Enhance EInkDisplayHandler and LVGLHandler with deep sleep functionality and partial refresh improvements

- Initialize LVGL with appropriate configuration and error handling.
- Create and initialize UIHandler to manage app icons and interactions.
- Register DemoApp and ShutdownApp with AppRegistry.
- Implement touch task and display initialization for EInkDisplayHandler.
- Handle shutdown signal by switching to ShutdownApp and performing cleanup.

dependencies.lock

@@ -51,16 +51,6 @@ dependencies:
     source:
       type: idf
     version: 5.5.2
-  joltwallet/littlefs:
-    component_hash: 1808d73e99168f6f3c26dd31799a248484762b3a320ec4962dec11a145f4277f
-    dependencies:
-    - name: idf
-      require: private
-      version: '>=5.0'
-    source:
-      registry_url: https://components.espressif.com/
-      type: service
-    version: 1.20.3
   lvgl/lvgl:
     component_hash: 17e68bfd21f0edf4c3ee838e2273da840bf3930e5dbc3bfa6c1190c3aed41f9f
     dependencies: []
@@ -73,8 +63,7 @@ direct_dependencies:
 - espressif/esp_lcd_touch_gt911
 - espressif/esp_lvgl_port
 - idf
-- joltwallet/littlefs
 - lvgl/lvgl
-manifest_hash: 534b6804ed0fcb2390bfe237db938fe86c9ba00561b361035a89dde4847214f2
+manifest_hash: 2010806782b4d2486b02b853afa44a545717d3d0593eb60f9aa6e5c696270f8f
 target: esp32s3
 version: 2.0.0

main/display/display.cpp.old

@@ -0,0 +1,199 @@
+#include "display/display.h"
+#include "common/constants.h"
+#include "esp_log.h"
+#include "esp_lcd_touch_gt911.h"
+
+#define BUSY_ACTIVE_LEVEL   0  // BUSY pin is active low
+#define BUSY_INACTIVE_LEVEL 1
+
+DisplayHandler::~DisplayHandler() {
+  if (_spi_mutex != nullptr) {
+    vSemaphoreDelete(_spi_mutex);
+  }
+  if (_spi != nullptr) {
+    spi_bus_remove_device(_spi);
+  }
+  if (_tp_handle != nullptr) {
+    esp_lcd_touch_del(_tp_handle);
+  }
+  if (_tp_io_handle != nullptr) {
+    esp_lcd_panel_io_del(_tp_io_handle);
+  }
+}
+
+void DisplayHandler::init_devices(bool set_display_ready /*= true*/) {
+  ESP_LOGI("DisplayHandler", "Initializing display and touch...");
+  _epd_init();
+  _touch_init();
+  ESP_LOGI("DisplayHandler", "Display and touch initialized.");
+  if (set_display_ready) {
+    ESP_LOGI("DisplayHandler", "Setting display ready bit.");
+    xEventGroupSetBits(_system_event_group, DISPLAY_READY_BIT | TOUCH_CALIBRATED_BIT);
+  }
+}
+
+
+void DisplayHandler::epd_write_cmd(uint8_t cmd) {
+  ESP_LOGI("DisplayHandler", "epd_write_cmd: waiting to send 0x%02X", cmd);
+  if (xSemaphoreTake(_spi_mutex, pdMS_TO_TICKS(5000)) != pdTRUE) {
+    ESP_LOGE("DisplayHandler", "SPI mutex timeout for cmd 0x%02X", cmd);
+    return;
+  }
+  _dangerous_epd_write_cmd_without_lock(cmd);
+  xSemaphoreGive(_spi_mutex);
+  ESP_LOGI("DisplayHandler", "epd_write_cmd: 0x%02X done", cmd);
+}
+
+void DisplayHandler::epd_write_data(uint8_t data) {
+  ESP_LOGI("DisplayHandler", "epd_write_data: waiting to send 0x%02X", data);
+  if (xSemaphoreTake(_spi_mutex, pdMS_TO_TICKS(5000)) != pdTRUE) {
+    ESP_LOGE("DisplayHandler", "SPI mutex timeout for data 0x%02X", data);
+    return;
+  }
+  _dangerous_epd_write_data_without_lock(data);
+  xSemaphoreGive(_spi_mutex);
+  ESP_LOGI("DisplayHandler", "epd_write_data: 0x%02X done", data);
+}
+
+void DisplayHandler::epd_write_cmd_with_data(uint8_t cmd, const uint8_t* data, size_t data_len) {
+  ESP_LOGI("DisplayHandler", "epd_write_cmd_with_data: waiting to send cmd 0x%02X with %u bytes of data", cmd, (unsigned)data_len);
+  if (xSemaphoreTake(_spi_mutex, pdMS_TO_TICKS(5000)) != pdTRUE) {
+    ESP_LOGE("DisplayHandler", "SPI mutex timeout for cmd with data 0x%02X", cmd);
+    return;
+  }
+  _dangerous_epd_write_cmd_without_lock(cmd);
+  for (size_t i = 0; i < data_len; ++i) {
+    _dangerous_epd_write_data_without_lock(data[i]);
+  }
+  xSemaphoreGive(_spi_mutex);
+  ESP_LOGI("DisplayHandler", "epd_write_cmd_with_data: cmd 0x%02X with %u bytes of data done", cmd, (unsigned)data_len);
+}
+
+//
+// Private methods
+//
+
+void DisplayHandler::_dangerous_epd_write_cmd_without_lock(uint8_t cmd) {
+  ESP_LOGI("DisplayHandler", "_dangerous_epd_write_cmd_without_lock: sending 0x%02X", cmd);
+  gpio_set_level(PIN_DC, 0); // Command mode
+  spi_transaction_t t {};
+  t.length = 8;t.tx_buffer = &cmd;
+  esp_err_t err = spi_device_polling_transmit(_spi, &t);
+  if (err != ESP_OK) {
+    ESP_LOGE("DisplayHandler", "Failed to send data 0x%02X", cmd);
+  } else {
+    ESP_LOGI("DisplayHandler", "_dangerous_epd_write_cmd_without_lock: 0x%02X sent", cmd);
+  }
+}
+
+void DisplayHandler::_dangerous_epd_write_data_without_lock(uint8_t data) {
+  ESP_LOGI("DisplayHandler", "_dangerous_epd_write_data_without_lock: sending 0x%02X", data);
+  gpio_set_level(PIN_DC, 1); // Data mode
+  spi_transaction_t t = { };
+  t.length = 8; t.tx_buffer = &data;
+  esp_err_t err = spi_device_polling_transmit(_spi, &t);
+  if (err != ESP_OK) {
+    ESP_LOGE("DisplayHandler", "Failed to send data 0x%02X", data);
+  } else {
+    ESP_LOGI("DisplayHandler", "_dangerous_epd_write_data_without_lock: 0x%02X sent", data);
+  }
+}
+
+// required to be called by inheriting class after SPI device is created
+void DisplayHandler::_epd_init(void) {
+  ESP_LOGI("DisplayHandler", "Initializing EPD...");
+  // 1. Hardware Reset
+  gpio_set_level(PIN_RST, 0);
+  vTaskDelay(pdMS_TO_TICKS(10));
+  gpio_set_level(PIN_RST, 1);
+  vTaskDelay(pdMS_TO_TICKS(10));
+
+  // 2. Initialization Sequence
+  const uint8_t panel_setting_data[] = { 0x1F };
+  epd_write_cmd_with_data(0x00, panel_setting_data, 1); // Panel Setting
+  vTaskDelay(pdMS_TO_TICKS(10));
+  const uint8_t vcom_data[] = { 0x10, 0x07 };
+  epd_write_cmd_with_data(0x50, vcom_data, 2); // VCOM
+  vTaskDelay(pdMS_TO_TICKS(10));
+  epd_write_cmd(0x04); // Power ON
+  vTaskDelay(pdMS_TO_TICKS(100)); // Wait for power on
+
+  // Check BUSY pin with detailed logging
+  ESP_LOGI("DisplayHandler", "Waiting for EPD to be ready after power on...");
+  ESP_LOGI("DisplayHandler", "BUSY pin level after power on: %d (0=BUSY, 1=FREE)", gpio_get_level(PIN_BUSY));
+
+  int busy_timeout = 0;
+  while (gpio_get_level(PIN_BUSY) == BUSY_ACTIVE_LEVEL) {  // BUSY is active LOW
+    vTaskDelay(pdMS_TO_TICKS(10));
+    busy_timeout++;
+    if (busy_timeout > 500) {  // 5 second timeout
+      ESP_LOGE("DisplayHandler", "EPD power on timeout! BUSY pin stuck at 0");
+      break;
+    }
+    if (busy_timeout % 50 == 0) {  // Log every 500ms
+      ESP_LOGW("DisplayHandler", "Still waiting for EPD power on, timeout: %d/500", busy_timeout);
+    }
+  }
+  ESP_LOGI("DisplayHandler", "EPD power on complete after %d * 10ms, BUSY pin: %d", busy_timeout, gpio_get_level(PIN_BUSY));
+  const uint8_t booster_data[] = { 0x27, 0x27, 0x18, 0x17 };
+  epd_write_cmd_with_data(0x06, booster_data, 4); // Booster Soft Start
+  vTaskDelay(pdMS_TO_TICKS(10));
+
+  // Enhanced display drive commands
+  const uint8_t e0_data[] = { 0x02 };
+  epd_write_cmd_with_data(0xE0, e0_data, 1);
+  const uint8_t e5_data[] = { 0x5A };
+  epd_write_cmd_with_data(0xE5, e5_data, 1);
+}
+
+void DisplayHandler::_touch_init(void) {
+  ESP_LOGI("DisplayHandler", "Initializing touch...");
+
+  // 1. Initialize I2C Bus
+  i2c_config_t conf = {};
+  conf.mode = I2C_MODE_MASTER;
+  conf.sda_io_num = PIN_TOUCH_SDA;
+  conf.scl_io_num = PIN_TOUCH_SCL;
+  conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
+  conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
+  conf.master.clk_speed = 400000;
+
+  i2c_param_config(I2C_NUM_0, &conf);
+  i2c_driver_install(I2C_NUM_0, I2C_MODE_MASTER, 0, 0, 0);
+  ESP_LOGI("DisplayHandler", "I2C driver installed");
+
+  // 2. Initialize GT911
+  ESP_LOGI("DisplayHandler", "Initializing GT911 touch controller...");
+  esp_lcd_panel_io_i2c_config_t tp_io_config = {};
+  // temporarily disable -Wmissing-field-initializers, as ESP_LCD_TOUCH_IO_I2C_GT911_CONFIG macro does not set all fields
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+  esp_lcd_panel_io_i2c_config_t default_tp_io_config = ESP_LCD_TOUCH_IO_I2C_GT911_CONFIG();
+#pragma GCC diagnostic pop
+  tp_io_config.dev_addr = default_tp_io_config.dev_addr;
+  tp_io_config.control_phase_bytes = default_tp_io_config.control_phase_bytes;
+  tp_io_config.dc_bit_offset = default_tp_io_config.dc_bit_offset;
+  tp_io_config.lcd_cmd_bits = default_tp_io_config.lcd_cmd_bits;
+  tp_io_config.flags = default_tp_io_config.flags;
+  esp_lcd_new_panel_io_i2c(I2C_NUM_0, &tp_io_config, &_tp_io_handle);
+
+  // GT911-specific config with I2C address (0x5D = INT low during reset)
+  static esp_lcd_touch_io_gt911_config_t gt911_config = {
+    .dev_addr = ESP_LCD_TOUCH_IO_I2C_GT911_ADDRESS  // 0x5D
+  };
+
+  esp_lcd_touch_config_t tp_cfg = {};
+  tp_cfg.x_max = 800;
+  tp_cfg.y_max = 480;
+  tp_cfg.rst_gpio_num = PIN_TOUCH_RST;
+  tp_cfg.int_gpio_num = PIN_TOUCH_IRQ;
+  tp_cfg.driver_data = &gt911_config;  // Pass GT911-specific config for automatic reset
+
+  esp_err_t touch_ret = esp_lcd_touch_new_i2c_gt911(_tp_io_handle, &tp_cfg, &_tp_handle);
+  if (touch_ret == ESP_OK && _tp_handle != nullptr) {
+    ESP_LOGI("DisplayHandler", "GT911 touch controller initialized successfully");
+  } else {
+    ESP_LOGE("DisplayHandler", "GT911 touch controller initialization failed: %s", esp_err_to_name(touch_ret));
+    _tp_handle = nullptr;
+  }
+}

main/display/display.h.old

@@ -0,0 +1,42 @@
+#pragma once
+#include "driver/spi_master.h"
+#include "driver/gpio.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_lcd_touch_gt911.h"
+#include "display/constants.h"
+#include <driver/i2c.h>
+
+class DisplayHandler {
+public:
+  DisplayHandler(
+    EventGroupHandle_t system_event_group
+  ) : _system_event_group(system_event_group) { }
+  virtual ~DisplayHandler();
+  
+  // required to be called by inheriting class after SPI device is created
+  // set set_display_ready to false if further initialization is needed before marking display ready
+  virtual void init_devices(bool set_display_ready = true);
+
+protected:
+  // Allow derived classes to access touch handle
+  esp_lcd_touch_handle_t get_touch_handle() const { return _tp_handle; }
+
+  void epd_write_cmd(uint8_t cmd);
+  void epd_write_data(uint8_t data);
+
+  void epd_write_cmd_with_data(uint8_t cmd, const uint8_t* data, size_t data_len);
+
+protected:
+  SemaphoreHandle_t _spi_mutex = xSemaphoreCreateMutex();
+  spi_device_handle_t _spi = nullptr;
+  EventGroupHandle_t _system_event_group = nullptr;
+  esp_lcd_panel_io_handle_t _tp_io_handle = nullptr;
+  esp_lcd_touch_handle_t _tp_handle = nullptr;
+
+  void _dangerous_epd_write_cmd_without_lock(uint8_t cmd);
+  void _dangerous_epd_write_data_without_lock(uint8_t data);
+
+  void _epd_init(void);
+  void _touch_init(void);
+};

main/display/eink_display_handler.cpp

@@ -11,53 +11,48 @@
 #define DISPLAY_BUFFER_SIZE (EINK_HEIGHT* EINK_WIDTH) / 8 // 1 bit per pixels
 #define MINIMUM_PIN_SETUP_DELAY_MS 10
 #define MINIMUM_POWER_ON_DELAY_MS 100
-#define PARTIAL_REFRESH_THRESHOLD 5  // Full refresh every N partial refreshes
+#define BUSY_ACTIVE_LEVEL   0  // BUSY pin is active low
+#define BUSY_INACTIVE_LEVEL 1
+#define DMA_TRANSFER_CHUNK_SIZE 4096  // 4KB chunk size for DMA transfers
 
-static uint8_t* DRAW_BUFFER; // 1 bit per pixel
-static uint8_t* OLD_DRAW_BUFFER; // 1 bit per pixel
-static uint8_t* black_data;
-static uint8_t* white_data;
+static uint8_t white_data[DISPLAY_BUFFER_SIZE]; // all white data
+static uint8_t black_data[DISPLAY_BUFFER_SIZE]; // all black data
 
 EInkDisplayHandler::EInkDisplayHandler() {
-  black_data = static_cast<uint8_t*>(heap_caps_malloc(DISPLAY_BUFFER_SIZE, MALLOC_CAP_SPIRAM));
-  white_data = static_cast<uint8_t*>(heap_caps_malloc(DISPLAY_BUFFER_SIZE, MALLOC_CAP_SPIRAM));
-  DRAW_BUFFER = static_cast<uint8_t*>(heap_caps_malloc(DISPLAY_BUFFER_SIZE, MALLOC_CAP_SPIRAM));
-  OLD_DRAW_BUFFER = static_cast<uint8_t*>(heap_caps_malloc(DISPLAY_BUFFER_SIZE, MALLOC_CAP_SPIRAM));
-  memset(black_data, 0xFF, DISPLAY_BUFFER_SIZE); // eink uses 1 for black
-  memset(white_data, 0x00, DISPLAY_BUFFER_SIZE);
-  memset(DRAW_BUFFER, 0x00, DISPLAY_BUFFER_SIZE); // start with all white (0 = white in e-ink)
-  memset(OLD_DRAW_BUFFER, 0x00, DISPLAY_BUFFER_SIZE); // start with all white (0 = white in e-ink)
-  draw_buffer_ = DRAW_BUFFER;
-  old_buffer_ = OLD_DRAW_BUFFER;
-
+  memset(white_data, 0xFF, sizeof(white_data));
+  memset(black_data, 0x00, sizeof(black_data));
+  spi_mutex_ = xSemaphoreCreateMutex();
+  if (spi_mutex_ == nullptr) {
+    ESP_LOGE(TAG, "Failed to create SPI mutex");
+  }
+  spi_transaction_mutex_ = xSemaphoreCreateMutex();
+  if (spi_transaction_mutex_ == nullptr) {
+    ESP_LOGE(TAG, "Failed to create SPI transaction mutex");
+  }
   refresh_mutex_ = xSemaphoreCreateMutex();
   if (refresh_mutex_ == nullptr) {
     ESP_LOGE(TAG, "Failed to create refresh mutex");
   }
 }
-
 EInkDisplayHandler::~EInkDisplayHandler() {
+  if (spi_mutex_ != nullptr) {
+    vSemaphoreDelete(spi_mutex_);
+  }
+  if (spi_transaction_mutex_ != nullptr) {
+    vSemaphoreDelete(spi_transaction_mutex_);
+  }
   if (refresh_mutex_ != nullptr) {
     vSemaphoreDelete(refresh_mutex_);
   }
+  if (spi_ != nullptr) {
+    spi_bus_remove_device(spi_);
+  }
   if (tp_handle_ != nullptr) {
     esp_lcd_touch_del(tp_handle_);
   }
   if (tp_io_handle_ != nullptr) {
     esp_lcd_panel_io_del(tp_io_handle_);
   }
-  if (black_data != nullptr) {
-    heap_caps_free(black_data);
-  }
-  if (white_data != nullptr) {
-    heap_caps_free(white_data);
-  }
-  if (DRAW_BUFFER != nullptr) {
-    heap_caps_free(DRAW_BUFFER);
-  }
-  if (OLD_DRAW_BUFFER != nullptr) {
-    heap_caps_free(OLD_DRAW_BUFFER);
-  }
 }
 
 esp_err_t EInkDisplayHandler::deep_sleep_display(void) {
@@ -68,26 +63,26 @@ esp_err_t EInkDisplayHandler::deep_sleep_display(void) {
   }
   {
     esp_err_t err = ESP_OK;
-    TransactionGuard transaction_guard(this->epd_handler_);
+    TransactionGuard transaction_guard(*this);
     err = transaction_guard.begin(pdMS_TO_TICKS(5000));
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to begin transaction for deep sleep: %s", esp_err_to_name(err));
       return err;
     }
-    epd_handler_.wait_for_idle();
+    wait_for_idle();
 
-    err = epd_handler_.epd_write_cmd(0x02, transaction_guard.transaction_id()); // power off
+    err = epd_write_cmd(0x02, transaction_guard.transaction_id()); // power off
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send power off command: %s", esp_err_to_name(err));
       return err;
     }
-    epd_handler_.wait_for_idle();
-    err = epd_handler_.epd_write_cmd(0x07, transaction_guard.transaction_id());   //deep sleep
+    wait_for_idle();
+    err = epd_write_cmd(0x07, transaction_guard.transaction_id());   //deep sleep
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send deep sleep command: %s", esp_err_to_name(err));
       return err;
     }
-    err = epd_handler_.epd_write_data(0xA5, transaction_guard.transaction_id());
+    err = epd_write_data(0xA5, transaction_guard.transaction_id());
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send deep sleep data: %s", esp_err_to_name(err));
       return err;
@@ -100,43 +95,32 @@ esp_err_t EInkDisplayHandler::deep_sleep_display(void) {
 esp_err_t EInkDisplayHandler::refresh_display() {
   esp_err_t err = ESP_OK;
 
-
   if (is_deep_sleep_) {
-
-    err = full_write(draw_buffer_, true);
-    if (err != ESP_OK) {
-      ESP_LOGE(TAG, "Full write failed during refresh_display: %s", esp_err_to_name(err));
-      return err;
+    epd_init_();
   }
-  } else {
-    // refresh does not correctly work after recovering from deep sleep due to sram reset
+
   {
     ESP_LOGI(TAG, "Waiting for display to be idle...");
-      TransactionGuard transaction_guard(this->epd_handler_);
+    TransactionGuard transaction_guard(*this);
     err = transaction_guard.begin(pdMS_TO_TICKS(10000));
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to begin transaction for display refresh: %s", esp_err_to_name(err));
       return err;
     }
-      if (is_deep_sleep_) {
-        epd_init_internal_(transaction_guard.transaction_id());
-      }
-
-      epd_handler_.wait_for_idle();
+    wait_for_idle();
     ESP_LOGI(TAG, "Starting display refresh...");
-      err = epd_handler_.epd_write_cmd(0x92, transaction_guard.transaction_id()); // enter normal mode
+    err = epd_write_cmd(0x92, transaction_guard.transaction_id()); // enter normal mode
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to enter normal mode: %s", esp_err_to_name(err));
       return err;
     }
-      err = epd_handler_.epd_write_cmd(0x12, transaction_guard.transaction_id()); // display refresh
+    err = epd_write_cmd(0x12, transaction_guard.transaction_id()); // display refresh
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send display refresh command: %s", esp_err_to_name(err));
       return err;
     }
     vTaskDelay(pdMS_TO_TICKS(MINIMUM_PIN_SETUP_DELAY_MS)); // at least 200us delay
-      epd_handler_.wait_for_idle();
-    }
+    wait_for_idle();
   }
 
   {
@@ -149,6 +133,12 @@ esp_err_t EInkDisplayHandler::refresh_display() {
     force_full_refresh_ = false;
   }
 
+  err = deep_sleep_display();
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to enter deep sleep after refresh: %s", esp_err_to_name(err));
+    return err;
+  }
+
   ESP_LOGI(TAG, "Refresh complete");
   return ESP_OK;
 }
@@ -157,35 +147,33 @@ esp_err_t EInkDisplayHandler::full_write(const uint8_t* framebuffer, const bool
   ESP_LOGI(TAG, "Starting full refresh (3 seconds)...");
   esp_err_t err = ESP_OK;
 
+  if (is_deep_sleep_) {
+    epd_init_();
+  }
 
   {
-    TransactionGuard transaction_guard(this->epd_handler_);
+    TransactionGuard transaction_guard(*this);
     err = transaction_guard.begin(pdMS_TO_TICKS(10000));
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to begin transaction for full refresh: %s", esp_err_to_name(err));
       return err;
     }
-    if (is_deep_sleep_) {
-      epd_init_internal_(transaction_guard.transaction_id());
-    }
 
-    write_to_buffer_(framebuffer, RefreshArea { 0, 0, DISPLAY_WIDTH - 1,  DISPLAY_HEIGHT - 1 });
-
-    epd_handler_.wait_for_idle();
+    wait_for_idle();
     // Step 0: Enter normal mode
-    err = epd_handler_.epd_write_cmd(0x92, transaction_guard.transaction_id()); // enter normal mode
+    err = epd_write_cmd(0x92, transaction_guard.transaction_id()); // enter normal mode
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to enter normal mode: %s", esp_err_to_name(err));
       return err;
     }
     // Step 1: Write old data (0x10) - Arduino uses 0xFF (all white) for base map
     {
-      err = epd_handler_.epd_write_cmd(0x10, transaction_guard.transaction_id());
+      err = epd_write_cmd(0x10, transaction_guard.transaction_id());
       if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to send old data command: %s", esp_err_to_name(err));
         return err;
       }
-      err = epd_handler_.transfer_spi_data(white_basemap ? black_data : white_data, DISPLAY_BUFFER_SIZE, transaction_guard.transaction_id()); // Send all white data (0xFF)
+      err = transfer_spi_data(white_basemap ? white_data : black_data, DISPLAY_BUFFER_SIZE, transaction_guard.transaction_id()); // Send all white data (0xFF)
       if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to send all white data for old data: %s", esp_err_to_name(err));
         return err;
@@ -194,20 +182,20 @@ esp_err_t EInkDisplayHandler::full_write(const uint8_t* framebuffer, const bool
 
     // Step 2: Write new data (0x13)
     {
-      err = epd_handler_.epd_write_cmd(0x13, transaction_guard.transaction_id());
+      err = epd_write_cmd(0x13, transaction_guard.transaction_id());
       if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to send new data command: %s", esp_err_to_name(err));
         return err;
       }
 
-      err = epd_handler_.transfer_spi_data(draw_buffer_, DISPLAY_BUFFER_SIZE, transaction_guard.transaction_id()); // Send new framebuffer data
+      err = transfer_spi_data(framebuffer, DISPLAY_BUFFER_SIZE, transaction_guard.transaction_id()); // Send new framebuffer data
       if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to send framebuffer data for new data: %s", esp_err_to_name(err));
         return err;
       }
     }
     // Step 3: Trigger display refresh (DRF)
-    err = epd_handler_.epd_write_cmd(0x12, transaction_guard.transaction_id());
+    err = epd_write_cmd(0x12, transaction_guard.transaction_id());
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send display refresh command: %s", esp_err_to_name(err));
       return err;
@@ -217,7 +205,7 @@ esp_err_t EInkDisplayHandler::full_write(const uint8_t* framebuffer, const bool
     ESP_LOGI(TAG, "Display refresh triggered, BUSY pin: %d", gpio_get_level(PIN_BUSY));
 
     // Wait for refresh to complete
-    epd_handler_.wait_for_idle();
+    wait_for_idle();
   }
 
   err = deep_sleep_display();
@@ -226,96 +214,57 @@ esp_err_t EInkDisplayHandler::full_write(const uint8_t* framebuffer, const bool
     return err;
   }
 
-  refresh_area_.reset();
-  memcpy(old_buffer_, draw_buffer_, DISPLAY_BUFFER_SIZE);
-
   ESP_LOGI(TAG, "Full refresh complete");
   return ESP_OK;
 }
 
-// TODO: Partial refresh is inverted in color
-esp_err_t EInkDisplayHandler::partial_refresh(const uint8_t* incoming_partial_framebuffer, const RefreshArea& incoming_area, const bool is_last_partial_update) {
+esp_err_t EInkDisplayHandler::partial_refresh(const uint8_t* partial_framebuffer, const RefreshArea& area) {
   ESP_LOGI(TAG, "Starting partial refresh (0.3 seconds)...");
   esp_err_t err = ESP_OK;
 
-  write_to_buffer_(incoming_partial_framebuffer, incoming_area);
-
-  // Always expand refresh_area_ to include incoming_area
-  refresh_area_.expand_to_include(incoming_area);
-
-  if (!is_last_partial_update) {
-    ESP_LOGI(TAG, "Partial refresh skipped (not last partial update)");
-    return ESP_OK;
-  }
-
-  {
-    TransactionGuard transaction_guard(this->epd_handler_);
-    err = transaction_guard.begin(pdMS_TO_TICKS(5000));
-    if (err != ESP_OK) {
-      ESP_LOGE(TAG, "Failed to begin transaction for partial refresh: %s", esp_err_to_name(err));
-      return err;
-    }
-    // Wake display from deep sleep INSIDE the transaction to prevent race conditions
-    if (is_deep_sleep_) {
-      err = epd_init_internal_(transaction_guard.transaction_id());
-      if (err != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to initialize EPD for partial refresh: %s", esp_err_to_name(err));
-        return err;
-      }
-      err = refresh_old_buffer_(transaction_guard.transaction_id());
-      if (err != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to refresh old buffer during partial refresh init: %s", esp_err_to_name(err));
-        return err;
-      }
-    }
-
-
-    RefreshArea area = refresh_area_;
-    if (area.x1 % 8 != 0 || area.x2 % 8 != 7) {
-      ESP_LOGE(TAG, "Partial refresh area x1 and x2 must be byte-aligned (x1 %% 8 == 0 and x2 %% 8 == 7)");
-      ESP_LOGI(TAG, "Given area: x1=%d, x2=%d", area.x1, area.x2);
-      return ESP_ERR_INVALID_ARG;
-    }
-
   // Calculate partial buffer size based on the refresh area
   const uint32_t area_width_bytes = (area.x2 - area.x1 + 1) / 8;
   const uint32_t area_height = area.y2 - area.y1 + 1;
   const size_t partial_buffer_size = area_width_bytes * area_height;
 
-    // uint8_t* partial_buffer = new uint8_t[partial_buffer_size];
-    uint8_t* partial_buffer = static_cast<uint8_t*>(heap_caps_malloc(partial_buffer_size, MALLOC_CAP_DMA | MALLOC_CAP_INTERNAL));
-
-    if (partial_buffer == nullptr) {
-      ESP_LOGE(TAG, "Failed to allocate partial buffer for partial refresh");
-      return ESP_ERR_NO_MEM;
-    }
-    // Copy the relevant area from draw_buffer_ to partial_buffer
-    for (int32_t row = 0; row < area_height; ++row) {
-      uint32_t fb_y = area.y1 + row;
-      uint32_t fb_x_byte_start = area.x1 / 8;
-      uint8_t* fb_ptr = &draw_buffer_[fb_y * (DISPLAY_WIDTH / 8) + fb_x_byte_start];
-      uint8_t* dest_ptr = &partial_buffer[row * area_width_bytes];
-      memcpy(dest_ptr, fb_ptr, area_width_bytes);
+  {
+    TransactionGuard transaction_guard(*this);
+    err = transaction_guard.begin(pdMS_TO_TICKS(5000));
+    if (err != ESP_OK) {
+      ESP_LOGE(TAG, "Failed to begin transaction for partial refresh: %s", esp_err_to_name(err));
+      return err;
     }
 
+    // Wake display from deep sleep INSIDE the transaction to prevent race conditions
+    if (is_deep_sleep_) {
+      err = epd_init_partial_internal_(transaction_guard.transaction_id());
+      if (err != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to initialize EPD for partial refresh: %s", esp_err_to_name(err));
+        return err;
+      }
+    }
 
-    epd_handler_.wait_for_idle();
+    wait_for_idle();
 
     // Step 1 VCOM setting
     std::vector<uint8_t> vcom_data = { 0xA9, 0x07 };
-    err = epd_handler_.epd_write_cmd_with_data(0x50, vcom_data, transaction_guard.transaction_id()); // VCOM for partial refresh
+    err = epd_write_cmd_with_data(0x50, vcom_data, transaction_guard.transaction_id()); // VCOM for partial refresh
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to set VCOM for partial refresh: %s", esp_err_to_name(err));
       return err;
     }
     // Step 2: Enter partial refresh mode
-    err = epd_handler_.epd_write_cmd(0x91, transaction_guard.transaction_id());  // Enter partial mode
+    err = epd_write_cmd(0x91, transaction_guard.transaction_id());  // Enter partial mode
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to enter partial refresh mode: %s", esp_err_to_name(err));
       return err;
     }
     // Step 3: Set partial window
     {
+      if (area.x1 % 8 != 0 || area.x2 % 8 != 7) {
+        ESP_LOGE(TAG, "Partial refresh area x1 and x2 must be byte-aligned (x1 %% 8 == 0 and x2 %% 8 == 7)");
+        return ESP_ERR_INVALID_ARG;
+      }
       // ------DD
       // DDDDD000
       // ------DD
@@ -353,41 +302,33 @@ esp_err_t EInkDisplayHandler::partial_refresh(const uint8_t* incoming_partial_fr
       ESP_LOGI(TAG, "Partial window data: %02X %02X %02X %02X %02X %02X %02X %02X",
         window_data[0], window_data[1], window_data[2], window_data[3], window_data[4],
         window_data[5], window_data[6], window_data[7]);
-      err = epd_handler_.epd_write_cmd_with_data(0x90, window_data, transaction_guard.transaction_id());  // Set partial window
+      err = epd_write_cmd_with_data(0x90, window_data, transaction_guard.transaction_id());  // Set partial window
       if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to send set partial window command: %s", esp_err_to_name(err));
         return err;
       }
     }
 
-    // Step 5: Write new data (0x13)
+    // Step 4: Write new data (0x13)
     {
-      err = epd_handler_.epd_write_cmd(0x13, transaction_guard.transaction_id());
+      err = epd_write_cmd(0x13, transaction_guard.transaction_id());
       if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to send new data command for partial refresh: %s", esp_err_to_name(err));
-        heap_caps_free(partial_buffer);
         return err;
       }
 
       // Send only the partial area data, not the full display buffer
-      ESP_LOGI(TAG, "Sending new partial buffer: %zu bytes (area: %dx%d)",
+      ESP_LOGI(TAG, "Sending partial buffer: %zu bytes (area: %dx%d)",
         partial_buffer_size, area_width_bytes * 8, area_height);
-      err = epd_handler_.transfer_spi_data(partial_buffer, partial_buffer_size, transaction_guard.transaction_id(), true); // Inverted for partial refresh
+      err = transfer_spi_data(partial_framebuffer, partial_buffer_size, transaction_guard.transaction_id());
       if (err != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to send partial_buffer data for partial refresh: %s", esp_err_to_name(err));
-        heap_caps_free(partial_buffer);
+        ESP_LOGE(TAG, "Failed to send partial_framebuffer data for partial refresh: %s", esp_err_to_name(err));
         return err;
       }
-
-      memcpy(old_buffer_, draw_buffer_, DISPLAY_BUFFER_SIZE);
     }
 
-    // Clean up partial buffer
-    heap_caps_free(partial_buffer);
-
-    // Step 6: Trigger partial display refresh (DRF)
-    // Use 0x12 (Display Update) command - same as full refresh, per sample code
-    err = epd_handler_.epd_write_cmd(0x12, transaction_guard.transaction_id());
+    // Step 5: Trigger partial display refresh (DRF) by ending the data write
+    err = epd_write_cmd(0x11, transaction_guard.transaction_id());
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send display refresh command for partial refresh: %s", esp_err_to_name(err));
       return err;
@@ -395,22 +336,15 @@ esp_err_t EInkDisplayHandler::partial_refresh(const uint8_t* incoming_partial_fr
 
     vTaskDelay(pdMS_TO_TICKS(MINIMUM_PIN_SETUP_DELAY_MS)); // at least 200us delay
 
-    epd_handler_.wait_for_idle();
-    // Step 7: Exit partial mode
-    err = epd_handler_.epd_write_cmd(0x92, transaction_guard.transaction_id());
+    wait_for_idle();
+    // Step 6: Exit partial mode
+    err = epd_write_cmd(0x92, transaction_guard.transaction_id());
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to exit partial refresh mode: %s", esp_err_to_name(err));
       return err;
     }
   }
   ESP_LOGI(TAG, "Partial refresh complete");
-
-  err = deep_sleep_display();
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to enter deep sleep after partial refresh: %s", esp_err_to_name(err));
-    return err;
-  }
-
   if (force_full_refresh_) {
     ESP_LOGI(TAG, "Full refresh already requested, skipping partial refresh count increment");
     err = refresh_display();
@@ -420,7 +354,6 @@ esp_err_t EInkDisplayHandler::partial_refresh(const uint8_t* incoming_partial_fr
     }
     return ESP_OK;
   }
-
   {
     SemaphoreGuard guard(refresh_mutex_);
     if (guard.take(pdMS_TO_TICKS(5000)) != pdTRUE) {
@@ -439,9 +372,11 @@ esp_err_t EInkDisplayHandler::partial_refresh(const uint8_t* incoming_partial_fr
     }
   }
 
-
-
-  refresh_area_.reset();
+  err = deep_sleep_display();
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to enter deep sleep after partial refresh: %s", esp_err_to_name(err));
+    return err;
+  }
 
   return ESP_OK;
 }
@@ -449,7 +384,7 @@ esp_err_t EInkDisplayHandler::partial_refresh(const uint8_t* incoming_partial_fr
 esp_err_t EInkDisplayHandler::clear_display(void) {
   ESP_LOGI(TAG, "Clearing display to all white...");
 
-  esp_err_t err = full_write(white_data, false);
+  esp_err_t err = full_write(black_data, false);
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "Failed to clear display: %s", esp_err_to_name(err));
     return err;
@@ -458,19 +393,7 @@ esp_err_t EInkDisplayHandler::clear_display(void) {
   return ESP_OK;
 }
 
-void EInkDisplayHandler::write_to_buffer_(const uint8_t* src_buffer, const RefreshArea& area) {
-  // Copy the relevant area from src_buffer to draw_buffer_
-  const uint32_t area_width_bytes = (area.x2 - area.x1 + 1) / 8;
-  const uint32_t area_height = area.y2 - area.y1 + 1;
 
-  for (int32_t row = 0; row < area_height; ++row) {
-    uint32_t fb_y = area.y1 + row;
-    uint32_t fb_x_byte_start = area.x1 / 8;
-    const uint8_t* src_ptr = &src_buffer[row * area_width_bytes];
-    uint8_t* dest_ptr = &draw_buffer_[fb_y * (DISPLAY_WIDTH / 8) + fb_x_byte_start];
-    memcpy(dest_ptr, src_ptr, area_width_bytes);
-  }
-}
 
 // Request a full refresh on next flush
 void EInkDisplayHandler::request_full_refresh(void) {
@@ -484,6 +407,26 @@ void EInkDisplayHandler::request_full_refresh(void) {
   }
 }
 
+// Check if display is busy (refreshing)
+bool EInkDisplayHandler::is_busy(void) const {
+  return gpio_get_level(PIN_BUSY) == BUSY_ACTIVE_LEVEL;  // BUSY is active LOW
+}
+void EInkDisplayHandler::wait_for_idle(void) const {
+  ESP_LOGI(TAG, "Waiting for display ready (BUSY pin)...");
+  int initial_level = gpio_get_level(PIN_BUSY);
+  ESP_LOGI(TAG, "Initial BUSY pin level: %d (0=BUSY, 1=FREE)", initial_level);
+
+  // If already free, no need to wait
+  if (initial_level == BUSY_INACTIVE_LEVEL) {
+    ESP_LOGI(TAG, "Display already ready (BUSY pin = 1)");
+    return;
+  }
+  while (gpio_get_level(PIN_BUSY) != BUSY_INACTIVE_LEVEL) {
+    vTaskDelay(pdMS_TO_TICKS(10));
+  }
+  ESP_LOGI(TAG, "Display is now ready (BUSY pin = 1)");
+}
+
 
 esp_err_t EInkDisplayHandler::init_devices(EventGroupHandle_t system_event_group) {
   esp_err_t err;
@@ -492,9 +435,9 @@ esp_err_t EInkDisplayHandler::init_devices(EventGroupHandle_t system_event_group
     ESP_LOGE(TAG, "Failed to initialize display pins: %s", esp_err_to_name(err));
     return err;
   }
-  err = this->epd_handler_.init();
+  err = epd_init_();
   if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize EPD handler: %s", esp_err_to_name(err));
+    ESP_LOGE(TAG, "Failed to initialize EPD: %s", esp_err_to_name(err));
     return err;
   }
   err = init_touch_();
@@ -502,6 +445,12 @@ esp_err_t EInkDisplayHandler::init_devices(EventGroupHandle_t system_event_group
     ESP_LOGE(TAG, "Failed to initialize touch: %s", esp_err_to_name(err));
     return err;
   }
+  err = deep_sleep_display();
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to put display into deep sleep: %s", esp_err_to_name(err));
+    return err;
+  }
+
   // if system_event_group is provided, set display ready bits
   if (system_event_group != nullptr) {
     // Indicate that display is ready
@@ -540,13 +489,50 @@ esp_err_t EInkDisplayHandler::init_display_pins_(void) {
     return ret;
   }
 
+  // Initialize SPI bus
+  spi_bus_config_t buscfg = {};
+  buscfg.mosi_io_num = 11;  // MOSI pin
+  buscfg.miso_io_num = -1;  // No MISO for e-paper
+  buscfg.sclk_io_num = 12;  // SCK pin
+  buscfg.quadwp_io_num = -1;
+  buscfg.quadhd_io_num = -1;
+  buscfg.max_transfer_sz = DISPLAY_BUFFER_SIZE;
+
+  ret = spi_bus_initialize(SPI2_HOST, &buscfg, SPI_DMA_CH_AUTO);
+  if (ret != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to initialize SPI bus: %s", esp_err_to_name(ret));
+    return ret;
+  }
+
+  // Add SPI device
+  spi_device_interface_config_t devcfg = {};
+  devcfg.clock_speed_hz = 10 * 1000 * 1000;  // 10 MHz
+  devcfg.mode = 0;  // SPI mode 0
+  devcfg.spics_io_num = PIN_CS;
+  devcfg.queue_size = 7;  // Queue size for non-blocking transactions
+  devcfg.pre_cb = nullptr;
+
+  ret = spi_bus_add_device(SPI2_HOST, &devcfg, &spi_);
+  if (ret != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to add SPI device: %s", esp_err_to_name(ret));
+    return ret;
+  }
   return ESP_OK;
 }
 
-esp_err_t EInkDisplayHandler::epd_init_internal_(uint32_t transaction_id) {
+
+// required to be called by inheriting class after SPI device is created
+esp_err_t EInkDisplayHandler::epd_init_(void) {
   ESP_LOGI(TAG, "Initializing EPD...");
   esp_err_t err;
 
+  {
+    TransactionGuard transaction_guard(*this);
+    esp_err_t begin_err = transaction_guard.begin();
+    if (begin_err != ESP_OK) {
+      ESP_LOGE(TAG, "Failed to begin transaction: %s", esp_err_to_name(begin_err));
+      return begin_err;
+    }
 
     // 1. Hardware Reset
     err = gpio_set_level(PIN_RST, 0);
@@ -564,20 +550,20 @@ esp_err_t EInkDisplayHandler::epd_init_internal_(uint32_t transaction_id) {
 
     // 2. Initialization Sequence
     std::vector<uint8_t> panel_setting_data = { 0x1F };
-  err = epd_handler_.epd_write_cmd_with_data(0x00, panel_setting_data, transaction_id); // Panel Setting
+    err = epd_write_cmd_with_data(0x00, panel_setting_data, transaction_guard.transaction_id()); // Panel Setting
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send Panel Setting command: %s", esp_err_to_name(err));
       return err;
     }
     vTaskDelay(pdMS_TO_TICKS(MINIMUM_PIN_SETUP_DELAY_MS));
     std::vector<uint8_t> vcom_data = { 0x10, 0x07 };
-  err = epd_handler_.epd_write_cmd_with_data(0x50, vcom_data, transaction_id); // VCOM
+    err = epd_write_cmd_with_data(0x50, vcom_data, transaction_guard.transaction_id()); // VCOM
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send VCOM command: %s", esp_err_to_name(err));
       return err;
     }
     vTaskDelay(pdMS_TO_TICKS(MINIMUM_PIN_SETUP_DELAY_MS));
-  err = epd_handler_.epd_write_cmd(0x04, transaction_id); // Power ON
+    err = epd_write_cmd(0x04, transaction_guard.transaction_id()); // Power ON
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send Power ON command: %s", esp_err_to_name(err));
       return err;
@@ -588,9 +574,21 @@ esp_err_t EInkDisplayHandler::epd_init_internal_(uint32_t transaction_id) {
     ESP_LOGI(TAG, "Waiting for EPD to be ready after power on...");
     ESP_LOGI(TAG, "BUSY pin level after power on: %d (0=BUSY, 1=FREE)", gpio_get_level(PIN_BUSY));
 
-  epd_handler_.wait_for_idle();
+    int busy_timeout = 0;
+    while (gpio_get_level(PIN_BUSY) == BUSY_ACTIVE_LEVEL) {  // BUSY is active LOW
+      vTaskDelay(pdMS_TO_TICKS(MINIMUM_PIN_SETUP_DELAY_MS));
+      busy_timeout++;
+      if (busy_timeout > 500) {  // 5 second timeout
+        ESP_LOGE(TAG, "EPD power on timeout! BUSY pin stuck at 0");
+        return ESP_ERR_TIMEOUT;
+      }
+      if (busy_timeout % 50 == 0) {  // Log every 500ms
+        ESP_LOGW(TAG, "Still waiting for EPD power on, timeout: %d/500", busy_timeout);
+      }
+    }
+    ESP_LOGI(TAG, "EPD power on complete after %d * 10ms, BUSY pin: %d", busy_timeout, gpio_get_level(PIN_BUSY));
     std::vector<uint8_t> booster_data = { 0x27, 0x27, 0x18, 0x17 };
-  err = epd_handler_.epd_write_cmd_with_data(0x06, booster_data, transaction_id); // Booster Soft Start
+    err = epd_write_cmd_with_data(0x06, booster_data, transaction_guard.transaction_id()); // Booster Soft Start
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send Booster Soft Start command: %s", esp_err_to_name(err));
       return err;
@@ -599,23 +597,32 @@ esp_err_t EInkDisplayHandler::epd_init_internal_(uint32_t transaction_id) {
 
     // Enhanced display drive commands
     std::vector<uint8_t> e0_data = { 0x02 };
-  err = epd_handler_.epd_write_cmd_with_data(0xE0, e0_data, transaction_id);
+    err = epd_write_cmd_with_data(0xE0, e0_data, transaction_guard.transaction_id());
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send Enhanced Display Drive command: %s", esp_err_to_name(err));
       return err;
     }
     std::vector<uint8_t> e5_data = { 0x5A };
-  err = epd_handler_.epd_write_cmd_with_data(0xE5, e5_data, transaction_id);
+    err = epd_write_cmd_with_data(0xE5, e5_data, transaction_guard.transaction_id());
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Failed to send Enhanced Display Drive command: %s", esp_err_to_name(err));
       return err;
     }
-
+  }
   is_deep_sleep_ = false;
-
   return err;
 }
 
+esp_err_t EInkDisplayHandler::epd_init_partial_(void) {
+  TransactionGuard transaction_guard(*this);
+  esp_err_t begin_err = transaction_guard.begin();
+  if (begin_err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to begin transaction: %s", esp_err_to_name(begin_err));
+    return begin_err;
+  }
+  return epd_init_partial_internal_(transaction_guard.transaction_id());
+}
+
 // Internal version that uses an existing transaction (no separate TransactionGuard)
 esp_err_t EInkDisplayHandler::epd_init_partial_internal_(uint32_t transaction_id) {
   ESP_LOGI(TAG, "Initializing EPD for partial refresh (internal)...");
@@ -637,7 +644,7 @@ esp_err_t EInkDisplayHandler::epd_init_partial_internal_(uint32_t transaction_id
 
   // 2. Panel Setting
   std::vector<uint8_t> panel_setting_data = { 0x1F };
-  err = epd_handler_.epd_write_cmd_with_data(0x00, panel_setting_data, transaction_id);
+  err = epd_write_cmd_with_data(0x00, panel_setting_data, transaction_id);
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "Failed to send Panel Setting command: %s", esp_err_to_name(err));
     return err;
@@ -645,37 +652,30 @@ esp_err_t EInkDisplayHandler::epd_init_partial_internal_(uint32_t transaction_id
   vTaskDelay(pdMS_TO_TICKS(MINIMUM_PIN_SETUP_DELAY_MS));
 
   // 3. Power ON
-  err = epd_handler_.epd_write_cmd(0x04, transaction_id);
+  err = epd_write_cmd(0x04, transaction_id);
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "Failed to send Power ON command: %s", esp_err_to_name(err));
     return err;
   }
   vTaskDelay(pdMS_TO_TICKS(MINIMUM_POWER_ON_DELAY_MS));
-  epd_handler_.wait_for_idle();
+  wait_for_idle();
 
   // 4. Partial initialization sequence - Enhanced Display Drive
   std::vector<uint8_t> e0_data = { 0x02 };
-  err = epd_handler_.epd_write_cmd_with_data(0xE0, e0_data, transaction_id);
+  err = epd_write_cmd_with_data(0xE0, e0_data, transaction_id);
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "Failed to send Enhanced Display Drive command (E0): %s", esp_err_to_name(err));
     return err;
   }
 
   std::vector<uint8_t> e5_data = { 0x6E };
-  err = epd_handler_.epd_write_cmd_with_data(0xE5, e5_data, transaction_id);
+  err = epd_write_cmd_with_data(0xE5, e5_data, transaction_id);
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "Failed to send Enhanced Display Drive command (E5): %s", esp_err_to_name(err));
     return err;
   }
 
   is_deep_sleep_ = false;
-
-  err = refresh_old_buffer_(transaction_id);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to refresh old buffer during partial init: %s", esp_err_to_name(err));
-    return err;
-  }
-
   ESP_LOGI(TAG, "EPD partial init (internal) complete");
   return ESP_OK;
 }
@@ -742,48 +742,201 @@ esp_err_t EInkDisplayHandler::init_touch_() {
   return err;
 }
 
-esp_err_t EInkDisplayHandler::refresh_old_buffer_(uint32_t transaction_id) {
-  ESP_LOGI(TAG, "Refreshing display SRAM to restore state after wake...");
-  esp_err_t err;
 
-  err = epd_handler_.epd_write_cmd(0x92, transaction_id); // enter normal mode
+esp_err_t EInkDisplayHandler::epd_write_cmd(const uint8_t cmd, uint32_t transaction_id) {
+  ESP_LOGI(TAG, "epd_write_cmd: waiting to send 0x%02X", cmd);
+
+  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
+  esp_err_t err =
+    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
   if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to enter normal mode: %s", esp_err_to_name(err));
+    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending cmd 0x%02X: %s",
+      cmd, esp_err_to_name(err));
     return err;
   }
 
-  // Write OLD data (0x10) as all 0x00 (white in e-ink terms)
-  // This tells the controller: "assume display was all white"
-  // Matches sample's EPD_WhiteScreen_ALL() which uses 0x00 for old SRAM
-  // The differential refresh: old=0 + new=0 → stay white, old=0 + new=1 → drive to black
-  err = epd_handler_.epd_write_cmd(0x10, transaction_id);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to send old data command: %s", esp_err_to_name(err));
+  SemaphoreGuard guard(spi_mutex_);
+  if (!guard.take(pdMS_TO_TICKS(5000))) {
+    ESP_LOGE(TAG, "SPI mutex timeout for cmd 0x%02X", cmd);
+    return ESP_ERR_TIMEOUT;
+  }
+  err = dangerous_epd_write_cmd_without_lock_(cmd);
+  ESP_LOGI(TAG, "epd_write_cmd: 0x%02X done", cmd);
   return err;
 }
 
-  // Send the old buffer as old data
-  err = epd_handler_.transfer_spi_data(old_buffer_, DISPLAY_BUFFER_SIZE, transaction_id);
+esp_err_t EInkDisplayHandler::epd_write_data(const uint8_t data, uint32_t transaction_id) {
+  ESP_LOGI(TAG, "epd_write_data: waiting to send 0x%02X", data);
+  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
+  esp_err_t err =
+    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
   if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to send white baseline to old SRAM: %s", esp_err_to_name(err));
+    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending data 0x%02X: %s",
+      data, esp_err_to_name(err));
+    return err;
+  }
+  SemaphoreGuard guard(spi_mutex_);
+  if (!guard.take(pdMS_TO_TICKS(5000))) {
+    ESP_LOGE(TAG, "SPI mutex timeout for data 0x%02X", data);
+    return ESP_ERR_TIMEOUT;
+  }
+  err = dangerous_epd_write_data_without_lock_(data);
+  ESP_LOGI(TAG, "epd_write_data: 0x%02X done", data);
   return err;
 }
 
-  // Write NEW data (0x13) with the actual display content
-  // This restores the display to show old_buffer_ content
-  err = epd_handler_.epd_write_cmd(0x13, transaction_id);
+esp_err_t EInkDisplayHandler::epd_write_cmd_with_data(const uint8_t cmd, std::vector<uint8_t>& data, uint32_t transaction_id) {
+  const size_t data_len = data.size();
+  ESP_LOGI(TAG, "epd_write_cmd_with_data: waiting to send cmd 0x%02X with %u bytes of data", cmd, data_len);
+
+  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
+  esp_err_t err =
+    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
   if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to send new data command: %s", esp_err_to_name(err));
+    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending cmd 0x%02X: %s, with data",
+      cmd, esp_err_to_name(err));
     return err;
   }
 
-  // Send the last displayed content to new SRAM
-  err = epd_handler_.transfer_spi_data(old_buffer_, DISPLAY_BUFFER_SIZE, transaction_id);
+  SemaphoreGuard guard(spi_mutex_);
+  if (!guard.take(pdMS_TO_TICKS(5000))) {
+    ESP_LOGE(TAG, "SPI mutex timeout for cmd with data 0x%02X", cmd);
+    return ESP_ERR_TIMEOUT;
+  }
+  err = dangerous_epd_write_cmd_without_lock_(cmd);
+  if (err != ESP_OK) {
+    return err;
+  };
+  for (size_t i = 0; i < data_len; ++i) {
+    err = dangerous_epd_write_data_without_lock_(data[i]);
     if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to send display content to new SRAM: %s", esp_err_to_name(err));
       return err;
     }
-
-  ESP_LOGI(TAG, "Display SRAM restored successfully");
+  }
+  ESP_LOGI(TAG, "epd_write_cmd_with_data: cmd 0x%02X with %u bytes of data done", cmd, data_len);
+  return ESP_OK;
+}
+
+
+esp_err_t EInkDisplayHandler::dangerous_epd_write_cmd_without_lock_(const uint8_t cmd) {
+  ESP_LOGI(TAG, "dangerous_epd_write_cmd_without_lock_: sending 0x%02X", cmd);
+  gpio_set_level(PIN_DC, 0); // Command mode
+  spi_transaction_t t {};
+  t.length = 8;t.tx_buffer = &cmd;
+  esp_err_t err = spi_device_polling_transmit(spi_, &t);
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to send data 0x%02X", cmd);
+  } else {
+    ESP_LOGI(TAG, "dangerous_epd_write_cmd_without_lock_: 0x%02X sent", cmd);
+  }
+  return err;
+}
+
+esp_err_t EInkDisplayHandler::dangerous_epd_write_data_without_lock_(const uint8_t data) {
+  ESP_LOGI(TAG, "dangerous_epd_write_data_without_lock_: sending 0x%02X", data);
+  gpio_set_level(PIN_DC, 1); // Data mode
+  spi_transaction_t t = { };
+  t.length = 8; t.tx_buffer = &data;
+  esp_err_t err = spi_device_polling_transmit(spi_, &t);
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to send data 0x%02X", data);
+  } else {
+    ESP_LOGI(TAG, "dangerous_epd_write_data_without_lock_: 0x%02X sent", data);
+  }
+  return err;
+}
+
+esp_err_t EInkDisplayHandler::transfer_spi_data(const uint8_t* data, const size_t& length, uint32_t transaction_id) {
+  ESP_LOGI(TAG, "transfer_spi_data: waiting to send %zu bytes of data", length);
+
+  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
+  esp_err_t err =
+    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending data of %zu bytes: %s",
+      length, esp_err_to_name(err));
+    return err;
+  }
+  SemaphoreGuard guard(spi_mutex_);
+  if (!guard.take(pdMS_TO_TICKS(5000))) {
+    ESP_LOGE(TAG, "SPI mutex timeout for data transfer of %zu bytes", length);
+    return ESP_ERR_TIMEOUT;
+  }
+  ESP_LOGI(TAG, "transfer_spi_data: starting to send %zu bytes of data", length);
+
+  size_t offset = 0;
+  size_t remaining = length;
+  gpio_set_level(PIN_DC, 1); // Data mode
+  while (remaining > 0) {
+    size_t transfer_size = (remaining < DMA_TRANSFER_CHUNK_SIZE) ? remaining : DMA_TRANSFER_CHUNK_SIZE;
+
+    spi_transaction_t t = {};
+    t.length = transfer_size * 8;  // Length in bits
+    t.tx_buffer = data + offset;
+
+    esp_err_t ret = spi_device_polling_transmit(spi_, &t);
+    if (ret != ESP_OK) {
+      ESP_LOGE(TAG, "Failed to send SPI chunk at offset %zu: %s", offset, esp_err_to_name(ret));
+      return ret;
+    }
+
+    remaining -= transfer_size;
+    offset += transfer_size;
+
+    // Yield every 16KB to prevent watchdog timeout
+    if (offset % (16 * 1024) == 0) {
+      ESP_LOGI(TAG, "New data progress: %zu/%zu bytes sent, yielding...", offset, length);
+      vTaskDelay(pdMS_TO_TICKS(1));
+    }
+  }
+
+  ESP_LOGI(TAG, "transfer_spi_data: completed sending %zu bytes of data", length);
+  return ESP_OK;
+}
+
+esp_err_t EInkDisplayHandler::begin_transaction_(TickType_t timeout, uint32_t& out_id) {
+  ESP_LOGI(TAG, "begin_transaction_: waiting to obtain transaction mutex");
+  if (xSemaphoreTake(spi_transaction_mutex_, timeout) != pdTRUE) {
+    ESP_LOGE(TAG, "begin_transaction_: transaction mutex timeout");
+    return ESP_ERR_TIMEOUT;
+  }
+
+  out_id = ++spi_transaction_id;
+  ESP_LOGI(TAG, "begin_transaction_: transaction mutex obtained");
+  return ESP_OK;
+}
+
+esp_err_t EInkDisplayHandler::end_transaction_(void) {
+  ESP_LOGI(TAG, "end_transaction_: releasing transaction mutex");
+  if (xSemaphoreGive(spi_transaction_mutex_) != pdTRUE) {
+    ESP_LOGE(TAG, "end_transaction_: failed to release transaction mutex");
+    return ESP_FAIL;
+  }
+
+  ESP_LOGI(TAG, "end_transaction_: transaction mutex released");
+  return ESP_OK;
+}
+
+esp_err_t EInkDisplayHandler::wait_for_transaction_end_(TickType_t timeout, uint32_t awaiting_transaction_id, SemaphoreGuard& out_transaction_guard) {
+  // Validate transaction ID if provided
+  if (awaiting_transaction_id != 0 && awaiting_transaction_id != spi_transaction_id) {
+    // Invalid transaction ID
+    ESP_LOGE(TAG, "Invalid transaction ID 0x%08X while waiting, current transaction ID: 0x%08X",
+      awaiting_transaction_id, spi_transaction_id);
+    return ESP_ERR_INVALID_ARG;
+  }
+  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
+  if (awaiting_transaction_id == 0) {
+    // wait for current transaction to complete
+    ESP_LOGV(TAG, "Waiting for current transaction 0x%08X to complete",
+      spi_transaction_id);
+    // take the mutex to ensure no transaction is active
+    if (!transaction_guard.take(timeout)) {
+      ESP_LOGE(TAG, "SPI transaction mutex timeout while waiting for transaction end");
+      return ESP_ERR_TIMEOUT;
+    }
+  }
+  // awaited_transaction_id is valid and matches current transaction ID or 0
+  out_transaction_guard = std::move(transaction_guard);
   return ESP_OK;
 }

main/display/eink_display_handler.cpp.old

@@ -0,0 +1,661 @@
+#include "display/eink_display_handler.h"
+#include "display/constants.h"
+#include "common/constants.h"
+#include "esp_log.h"
+#include "esp_heap_caps.h"
+#include "esp_task_wdt.h"
+#include <cstring>
+
+#define TAG "EInkDisplayHandler"
+#define BUSY_ACTIVE_LEVEL   0  // BUSY pin is active low
+#define BUSY_INACTIVE_LEVEL 1
+
+EInkDisplayHandler::EInkDisplayHandler(EventGroupHandle_t system_event_group)
+  : DisplayHandler(system_event_group) {
+  _refresh_mutex = xSemaphoreCreateMutex();
+  if (_refresh_mutex == nullptr) {
+    ESP_LOGE(TAG, "Failed to create refresh mutex");
+  }
+}
+
+EInkDisplayHandler::~EInkDisplayHandler() {
+  if (_refresh_task_handle != nullptr) {
+    vTaskDelete(_refresh_task_handle);
+  }
+  if (_touch_task_handle != nullptr) {
+    vTaskDelete(_touch_task_handle);
+  }
+  if (_refresh_queue != nullptr) {
+    vQueueDelete(_refresh_queue);
+  }
+  if (_lvgl_display != nullptr) {
+    lv_display_delete(_lvgl_display);
+    _lvgl_display = nullptr;
+    if (_lvgl_draw_buf != nullptr) {
+      lv_draw_buf_destroy(_lvgl_draw_buf);
+      _lvgl_draw_buf = nullptr;
+    }
+  }
+  if (_lvgl_touch_indev != nullptr) {
+    lvgl_port_remove_touch(_lvgl_touch_indev);
+  }
+  if (_framebuffer != nullptr) {
+    heap_caps_free(_framebuffer);
+  }
+  if (_refresh_mutex != nullptr) {
+    vSemaphoreDelete(_refresh_mutex);
+  }
+}
+
+void EInkDisplayHandler::init() {
+  ESP_LOGI(TAG, "Initializing E-Ink display handler...");
+
+  // Initialize GPIO pins
+  gpio_config_t io_conf = {};
+  io_conf.pin_bit_mask = (1ULL << PIN_DC) | (1ULL << PIN_RST);
+  io_conf.mode = GPIO_MODE_OUTPUT;
+  io_conf.pull_up_en = GPIO_PULLUP_DISABLE;
+  io_conf.pull_down_en = GPIO_PULLDOWN_DISABLE;
+  io_conf.intr_type = GPIO_INTR_DISABLE;
+  gpio_config(&io_conf);
+
+  // Configure BUSY pin as input (no pull-up like sample code)
+  io_conf.pin_bit_mask = (1ULL << PIN_BUSY);
+  io_conf.mode = GPIO_MODE_INPUT;
+  io_conf.pull_up_en = GPIO_PULLUP_DISABLE;
+  gpio_config(&io_conf);
+
+  // Initialize SPI bus
+  spi_bus_config_t buscfg = {};
+  buscfg.mosi_io_num = 11;  // MOSI pin
+  buscfg.miso_io_num = -1;  // No MISO for e-paper
+  buscfg.sclk_io_num = 12;  // SCK pin
+  buscfg.quadwp_io_num = -1;
+  buscfg.quadhd_io_num = -1;
+  buscfg.max_transfer_sz = DISPLAY_BUFFER_SIZE;
+
+  esp_err_t ret = spi_bus_initialize(SPI2_HOST, &buscfg, SPI_DMA_CH_AUTO);
+  if (ret != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to initialize SPI bus: %s", esp_err_to_name(ret));
+    return;
+  }
+
+  // Add SPI device
+  spi_device_interface_config_t devcfg = {};
+  devcfg.clock_speed_hz = 6 * 1000 * 1000;  // 6 MHz (reduced for reliability)
+  devcfg.mode = 0;  // SPI mode 0
+  devcfg.spics_io_num = PIN_CS;
+  devcfg.queue_size = 7;  // Queue size for non-blocking transactions
+  devcfg.pre_cb = nullptr;
+
+  ret = spi_bus_add_device(SPI2_HOST, &devcfg, &_spi);
+  if (ret != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to add SPI device: %s", esp_err_to_name(ret));
+    return;
+  }
+
+  // Initialize base display and touch devices
+  init_devices(false);  // Don't set ready bit yet
+
+  // Create refresh queue (queue 5 refresh requests)
+  _refresh_queue = xQueueCreate(5, sizeof(bool));
+  if (_refresh_queue == nullptr) {
+    ESP_LOGE(TAG, "Failed to create refresh queue");
+    return;
+  }
+
+  // Create refresh task
+  BaseType_t ret_task = xTaskCreatePinnedToCore(
+    _refresh_task,
+    "eink_refresh",
+    8192,
+    this,
+    5,  // Priority - lower than LVGL task
+    &_refresh_task_handle,
+    1   // Pin to core 1
+  );
+  if (ret_task != pdPASS) {
+    ESP_LOGE(TAG, "Failed to create refresh task");
+    return;
+  }
+
+  // Allocate framebuffer - try PSRAM first, fallback to internal RAM
+  // Note: Internal framebuffer excludes the 8-byte palette (raw pixel data only)
+  const size_t fb_size = DISPLAY_BUFFER_SIZE - 8;  // Exclude palette from internal storage
+  _framebuffer = (uint8_t*)heap_caps_malloc(fb_size, MALLOC_CAP_SPIRAM);
+  if (_framebuffer != nullptr) {
+    _framebuffer_in_psram = true;
+    ESP_LOGI(TAG, "Framebuffer allocated in PSRAM (%zu bytes, LVGL buffer: %d bytes)",
+      fb_size, DISPLAY_BUFFER_SIZE);
+  } else {
+    ESP_LOGW(TAG, "PSRAM not available, allocating framebuffer in internal RAM");
+    _framebuffer = (uint8_t*)heap_caps_malloc(fb_size, MALLOC_CAP_INTERNAL);
+    _framebuffer_in_psram = false;
+    if (_framebuffer == nullptr) {
+      ESP_LOGE(TAG, "Failed to allocate framebuffer");
+      return;
+    }
+    ESP_LOGI(TAG, "Framebuffer allocated in internal RAM (%zu bytes, LVGL buffer: %d bytes)",
+      fb_size, DISPLAY_BUFFER_SIZE);
+  }
+  memset(_framebuffer, 0xFF, fb_size);  // Initialize to white
+
+  // Perform initial full refresh to clear display BEFORE creating LVGL display
+  // This prevents LVGL from trying to render during the initial clear
+  ESP_LOGI(TAG, "Performing initial display clear...");
+  _perform_full_refresh(_framebuffer);
+  ESP_LOGI(TAG, "Initial display clear complete");
+
+  // Create LVGL display manually (no esp_lcd panel for e-paper)
+  lv_display_t* disp = lv_display_create(DISPLAY_WIDTH, DISPLAY_HEIGHT);
+  if (disp == nullptr) {
+    ESP_LOGE(TAG, "Failed to create LVGL display");
+    return;
+  }
+
+  /* 1-bit e-paper display */
+  lv_display_set_color_format(disp, LV_COLOR_FORMAT_I1);
+
+  /* Disable antialiasing for monochrome display to ensure crisp 1px lines */
+  lv_display_set_antialiasing(disp, false);
+
+  /* Create a draw buffer covering ~40 lines */
+  _lvgl_draw_buf = lv_draw_buf_create(DISPLAY_WIDTH, DISPLAY_HEIGHT, LV_COLOR_FORMAT_I1, LV_STRIDE_AUTO);
+  if (_lvgl_draw_buf == nullptr) {
+    ESP_LOGE(TAG, "Failed to create LVGL draw buffer");
+    lv_display_delete(disp);
+    return;
+  }
+
+  lv_display_set_draw_buffers(disp, _lvgl_draw_buf, NULL);
+  lv_display_set_render_mode(disp, LV_DISPLAY_RENDER_MODE_DIRECT);
+
+  // Set custom flush callback and user data
+  lv_display_set_flush_cb(disp, _lvgl_flush_cb);
+  lv_display_set_user_data(disp, this);
+
+  _lvgl_display = disp;
+
+  ESP_LOGI(TAG, "LVGL display registered");
+
+  // Register GT911 touch input with LVGL, only if touch handle is valid
+  esp_lcd_touch_handle_t tp_handle = get_touch_handle();
+  if (tp_handle == nullptr) {
+    ESP_LOGE(TAG, "Touch handle is NULL — touch initialization failed; skipping LVGL touch registration");
+  } else {
+    const lvgl_port_touch_cfg_t touch_cfg = {
+      .disp = _lvgl_display,
+      .handle = tp_handle,
+      .scale = {}, // Default scaling
+    };
+
+    _lvgl_touch_indev = lvgl_port_add_touch(&touch_cfg);
+    if (_lvgl_touch_indev == nullptr) {
+      ESP_LOGE(TAG, "Failed to register LVGL touch input");
+      return;
+    }
+
+    // Override touch read callback to check BUSY pin
+    lv_indev_set_read_cb(_lvgl_touch_indev, _lvgl_touch_read_cb);
+    lv_indev_set_user_data(_lvgl_touch_indev, this);
+
+    ESP_LOGI(TAG, "LVGL touch input registered");
+  }
+
+  // Set display ready bits
+  xEventGroupSetBits(_system_event_group, DISPLAY_READY_BIT | TOUCH_CALIBRATED_BIT);
+  ESP_LOGI(TAG, "E-Ink display handler initialized successfully");
+}
+
+void EInkDisplayHandler::start_touch_task() {
+  // Note: With lvgl_port_add_touch, the ESP-IDF LVGL port handles touch reading internally
+  // We don't need a separate touch task unless we want custom processing
+  ESP_LOGI(TAG, "Touch input handled by LVGL port");
+}
+
+void EInkDisplayHandler::request_full_refresh() {
+  if (xSemaphoreTake(_refresh_mutex, pdMS_TO_TICKS(100)) == pdTRUE) {
+    _force_full_refresh = true;
+    _partial_refresh_count = 0;
+    xSemaphoreGive(_refresh_mutex);
+    ESP_LOGI(TAG, "Full refresh requested");
+  }
+}
+
+bool EInkDisplayHandler::is_busy() const {
+  return gpio_get_level(PIN_BUSY) == BUSY_ACTIVE_LEVEL;  // BUSY is active LOW
+}
+
+void EInkDisplayHandler::_lvgl_flush_cb(lv_display_t* disp, const lv_area_t* area, uint8_t* px_map) {
+  EInkDisplayHandler* handler = static_cast<EInkDisplayHandler*>(lv_display_get_user_data(disp));
+  if (handler == nullptr) {
+    ESP_LOGE(TAG, "Invalid handler in flush callback");
+    lv_display_flush_ready(disp);
+    return;
+  }
+
+  // Check if display is busy with detailed logging
+  int busy_level = gpio_get_level(PIN_BUSY);
+  ESP_LOGI(TAG, "Flush callback: BUSY pin = %d, is_busy() = %d", busy_level, handler->is_busy());
+
+  if (handler->is_busy()) {
+    ESP_LOGW(TAG, "Display busy (BUSY pin = 0), skipping flush");
+    lv_display_flush_ready(disp);
+    return;
+  }
+
+  // Wait for any ongoing refresh to complete
+  handler->_wait_for_busy();
+
+  bool perform_full_refresh = false;
+
+  if (xSemaphoreTake(handler->_refresh_mutex, pdMS_TO_TICKS(100)) == pdTRUE) {
+    // Check if full refresh is needed
+    if (handler->_force_full_refresh) {
+      perform_full_refresh = true;
+      handler->_force_full_refresh = false;
+      handler->_partial_refresh_count = 0;
+    } else {
+      handler->_partial_refresh_count++;
+      if (handler->_partial_refresh_count >= PARTIAL_REFRESH_THRESHOLD) {
+        perform_full_refresh = true;
+        handler->_partial_refresh_count = 0;
+      }
+    }
+    xSemaphoreGive(handler->_refresh_mutex);
+  }
+
+  // Copy LVGL buffer to framebuffer
+  // For 1-bit mode, LVGL provides data in packed format (8 pixels per byte)
+  // CRITICAL: Skip first 8 bytes (LVGL I1 palette) as per LVGL documentation
+  uint8_t* pixel_data = px_map + 8;  // Skip 8-byte palette
+  int32_t w = lv_area_get_width(area);
+  int32_t h = lv_area_get_height(area);
+
+  ESP_LOGI(TAG, "Flushing area: x=%d, y=%d, w=%d, h=%d, full_refresh=%d",
+    area->x1, area->y1, w, h, perform_full_refresh);
+  ESP_LOGI(TAG, "Buffer: px_map=%p, pixel_data=%p, palette skipped: %d bytes",
+    (void*)px_map, (void*)pixel_data, 8);
+
+  // Check if this is a full screen update - if so, simple copy
+  if (area->x1 == 0 && area->y1 == 0 && w == DISPLAY_WIDTH && h == DISPLAY_HEIGHT) {
+    ESP_LOGI(TAG, "Full screen update, direct copy (skipping palette)");
+    memcpy(handler->_framebuffer, pixel_data, DISPLAY_BUFFER_SIZE - 8);
+  } else {
+    ESP_LOGI(TAG, "Partial area update");
+    // In DIRECT render mode, px_map points to the full screen buffer
+    // The stride is always the full display width
+    const uint32_t stride = DISPLAY_WIDTH / 8;  // 800 / 8 = 100 bytes per row
+
+    // Check if we can do row-by-row copy (byte-aligned on both x1 and width)
+    bool byte_aligned = (area->x1 % 8 == 0) && (w % 8 == 0);
+
+    if (byte_aligned) {
+      // Optimized: byte-aligned row copy
+      ESP_LOGI(TAG, "Byte-aligned copy: x=%ld, y=%ld, w=%ld, h=%ld",
+        (long)area->x1, (long)area->y1, (long)w, (long)h);
+
+      uint32_t x_byte = area->x1 / 8;
+      uint32_t width_bytes = w / 8;
+
+      for (int32_t y = 0; y < h; y++) {
+        int32_t fb_y = area->y1 + y;
+        if (fb_y >= DISPLAY_HEIGHT) break;
+
+        uint8_t* src = pixel_data + (fb_y * stride + x_byte);
+        uint8_t* dst = handler->_framebuffer + (fb_y * stride + x_byte);
+        memcpy(dst, src, width_bytes);
+      }
+    } else {
+      // Bit-level copy for non-aligned regions
+      ESP_LOGI(TAG, "Bit-level copy: x=%ld, y=%ld, w=%ld, h=%ld",
+        (long)area->x1, (long)area->y1, (long)w, (long)h);
+
+      for (int32_t y = 0; y < h; y++) {
+        int32_t fb_y = area->y1 + y;
+        if (fb_y >= DISPLAY_HEIGHT) break;
+
+        for (int32_t x = 0; x < w; x++) {
+          int32_t fb_x = area->x1 + x;
+          if (fb_x >= DISPLAY_WIDTH) break;
+
+          // Get pixel from source buffer (using full screen coordinates)
+          size_t src_byte_idx = fb_y * stride + (fb_x / 8);
+          size_t src_bit_idx = fb_x % 8;
+          uint8_t src_bit = (pixel_data[src_byte_idx] >> (7 - src_bit_idx)) & 0x01;
+
+          // Set pixel in destination buffer
+          size_t dst_byte_idx = fb_y * stride + (fb_x / 8);
+          size_t dst_bit_idx = fb_x % 8;
+
+          if (dst_byte_idx < (DISPLAY_BUFFER_SIZE - 8)) {
+            if (src_bit) {
+              handler->_framebuffer[dst_byte_idx] |= (1 << (7 - dst_bit_idx));
+            } else {
+              handler->_framebuffer[dst_byte_idx] &= ~(1 << (7 - dst_bit_idx));
+            }
+          }
+        }
+      }
+    }
+  }
+
+  // Queue refresh request (non-blocking)
+  if (handler->_refresh_queue != nullptr) {
+    if (xQueueSend(handler->_refresh_queue, &perform_full_refresh, 0) != pdPASS) {
+      ESP_LOGW(TAG, "Refresh queue full, skipping refresh");
+    } else {
+      ESP_LOGI(TAG, "Queued %s refresh", perform_full_refresh ? "full" : "partial");
+    }
+  }
+
+  lv_display_flush_ready(disp);
+}
+
+void EInkDisplayHandler::_lvgl_touch_read_cb(lv_indev_t* indev, lv_indev_data_t* data) {
+  EInkDisplayHandler* handler = static_cast<EInkDisplayHandler*>(lv_indev_get_user_data(indev));
+
+  // Disable touch input during display refresh (BUSY)
+  if (handler->is_busy()) {
+    data->state = LV_INDEV_STATE_RELEASED;
+    data->continue_reading = false;
+    return;
+  }
+
+  esp_lcd_touch_handle_t tp_handle = handler->get_touch_handle();
+  if (tp_handle == nullptr) {
+    data->state = LV_INDEV_STATE_RELEASED;
+    return;
+  }
+
+
+  // Read touch data from GT911
+  esp_err_t ret = esp_lcd_touch_read_data(tp_handle);
+  if (ret == ESP_OK) {
+    uint8_t touch_cnt = 0;
+    // Get touch data using new API
+    esp_lcd_touch_point_data_t point_data[1];
+    esp_lcd_touch_get_data(tp_handle, point_data, &touch_cnt, 1);
+
+    if (touch_cnt > 0) {
+      ESP_LOGI(TAG, "Touch data read successfully: x=%d, y=%d", point_data[0].x, point_data[0].y);
+      data->point.x = point_data[0].x;
+      data->point.y = point_data[0].y;
+      data->state = LV_INDEV_STATE_PRESSED;
+    } else {
+      data->state = LV_INDEV_STATE_RELEASED;
+    }
+  } else {
+    data->state = LV_INDEV_STATE_RELEASED;
+  }
+
+  data->continue_reading = false;
+}
+
+void EInkDisplayHandler::_perform_full_refresh(const uint8_t* framebuffer) {
+  ESP_LOGI(TAG, "Starting full refresh (3 seconds)...");
+
+  _wait_for_busy();
+
+  // Step 1: Write old data (0x10) - Arduino uses 0xFF (all white) for base map
+  epd_write_cmd(0x10);
+
+  if (xSemaphoreTake(_spi_mutex, pdMS_TO_TICKS(5000)) != pdTRUE) {
+    ESP_LOGE(TAG, "SPI mutex timeout in full refresh step 1");
+    return;
+  }
+  gpio_set_level(PIN_DC, 1);  // Data mode
+
+  ESP_LOGI(TAG, "Starting SPI data transmission for old data (0x10)...");
+
+  // Send 0xFF (white) for all old data, matching Arduino EPD_SetRAMValue_BaseMap
+  // Use DMA transfers in chunks for better performance
+  static uint8_t white_buffer[4096];  // 4KB chunk buffer
+  memset(white_buffer, 0xFF, sizeof(white_buffer));
+
+  const size_t CHUNK_SIZE = sizeof(white_buffer);
+  size_t remaining = DISPLAY_BUFFER_SIZE - 8;  // Exclude palette from transmission
+  size_t offset = 0;
+
+  while (remaining > 0) {
+    size_t transfer_size = (remaining < CHUNK_SIZE) ? remaining : CHUNK_SIZE;
+
+    spi_transaction_t t = {};
+    t.length = transfer_size * 8;  // Length in bits
+    t.tx_buffer = white_buffer;
+
+    esp_err_t ret = spi_device_polling_transmit(_spi, &t);
+    if (ret != ESP_OK) {
+      ESP_LOGE(TAG, "Failed to send SPI chunk at offset %zu: %s", offset, esp_err_to_name(ret));
+      break;
+    }
+
+    remaining -= transfer_size;
+    offset += transfer_size;
+
+    // Yield every 16KB to prevent watchdog timeout
+    if (offset % (16 * 1024) == 0) {
+      ESP_LOGI(TAG, "Old data progress: %zu/%zu bytes (%.1f%%)", offset, remaining,
+        (float)offset * 100.0f / (float)remaining);
+      vTaskDelay(pdMS_TO_TICKS(1));
+    }
+  }
+  ESP_LOGI(TAG, "Completed SPI data transmission for old data");
+  xSemaphoreGive(_spi_mutex);
+
+  // Step 2: Write new data (0x13)
+  epd_write_cmd(0x13);
+
+  if (xSemaphoreTake(_spi_mutex, pdMS_TO_TICKS(5000)) != pdTRUE) {
+    ESP_LOGE(TAG, "SPI mutex timeout in full refresh step 2");
+    return;
+  }
+  gpio_set_level(PIN_DC, 1);  // Data mode
+
+  ESP_LOGI(TAG, "Starting SPI data transmission for new data (0x13)...");
+
+  // Send actual framebuffer data in chunks using DMA for better performance
+  offset = 0;
+  remaining = DISPLAY_BUFFER_SIZE - 8;  // Reset remaining for step 2
+
+  while (remaining > 0) {
+    size_t transfer_size = (remaining < CHUNK_SIZE) ? remaining : CHUNK_SIZE;
+
+    spi_transaction_t t = {};
+    t.length = transfer_size * 8;  // Length in bits
+    t.tx_buffer = framebuffer + offset;
+
+    esp_err_t ret = spi_device_polling_transmit(_spi, &t);
+    if (ret != ESP_OK) {
+      ESP_LOGE(TAG, "Failed to send SPI chunk at offset %zu: %s", offset, esp_err_to_name(ret));
+      break;
+    }
+
+    remaining -= transfer_size;
+    offset += transfer_size;
+
+    // Yield every 16KB to prevent watchdog timeout
+    if (offset % (16 * 1024) == 0) {
+      ESP_LOGI(TAG, "New data progress: %zu/%zu bytes (%.1f%%)", offset, remaining,
+        (float)offset * 100.0f / (float)remaining);
+      vTaskDelay(pdMS_TO_TICKS(1));
+    }
+  }
+
+  ESP_LOGI(TAG, "Completed SPI data transmission for new data");
+  xSemaphoreGive(_spi_mutex);
+
+  // Step 3: Trigger display refresh (DRF)
+  epd_write_cmd(0x12);
+  // Critical delay - sample code says "!!!The delay here is necessary, 200uS at least!!!"
+  vTaskDelay(pdMS_TO_TICKS(10));
+  ESP_LOGI(TAG, "Display refresh triggered, BUSY pin: %d", gpio_get_level(PIN_BUSY));
+
+  // Wait for refresh to complete
+  _wait_for_busy();
+
+  ESP_LOGI(TAG, "Full refresh complete");
+}
+
+void EInkDisplayHandler::_perform_partial_refresh(const uint8_t* framebuffer) {
+  ESP_LOGI(TAG, "Starting partial refresh (0.3 seconds)...");
+
+  _wait_for_busy();
+
+  // Step 1: Configure VCOM for partial refresh
+  const uint8_t vcom_data[] = { 0xA9, 0x07 };
+  epd_write_cmd_with_data(0x50, vcom_data, 2);
+
+  // Step 2: Enter partial refresh mode
+  epd_write_cmd(0x91);
+
+  // Step 3: Define partial window (full screen for now)
+  // Format: 0x90 + 9 bytes (x_start_H, x_start_L, x_end_H, x_end_L, y_start_H, y_start_L, y_end_H, y_end_L, 0x01)
+  // For full screen: x=0 to 799 (0x031F), y=0 to 479 (0x01DF)
+  const uint8_t window_data[] = {
+    0x00, 0x00,  // x_start = 0
+    0x03, 0x1F,  // x_end = 799 (0x31F)
+    0x00, 0x00,  // y_start = 0
+    0x01, 0xDF,  // y_end = 479 (0x1DF)
+    0x01         // PT_SCAN
+  };
+  epd_write_cmd_with_data(0x90, window_data, 9);
+
+  // Step 4: Write new data (0x13 command)
+  epd_write_cmd(0x13);
+
+  if (xSemaphoreTake(_spi_mutex, pdMS_TO_TICKS(5000)) != pdTRUE) {
+    ESP_LOGE(TAG, "SPI mutex timeout in partial refresh");
+    return;
+  }
+  gpio_set_level(PIN_DC, 1);  // Data mode
+
+  ESP_LOGI(TAG, "Starting SPI data transmission for partial refresh...");
+
+  // Send framebuffer data in chunks using DMA for better performance
+  const size_t CHUNK_SIZE = 4096;  // 4KB chunks
+  size_t remaining = DISPLAY_BUFFER_SIZE - 8;  // Exclude palette from transmission
+  size_t offset = 0;
+
+  while (remaining > 0) {
+    size_t transfer_size = (remaining < CHUNK_SIZE) ? remaining : CHUNK_SIZE;
+
+    spi_transaction_t t = {};
+    t.length = transfer_size * 8;  // Length in bits
+    t.tx_buffer = framebuffer + offset;
+
+    esp_err_t ret = spi_device_polling_transmit(_spi, &t);
+    if (ret != ESP_OK) {
+      ESP_LOGE(TAG, "Failed to send SPI chunk at offset %zu: %s", offset, esp_err_to_name(ret));
+      break;
+    }
+
+    remaining -= transfer_size;
+    offset += transfer_size;
+
+    // Yield every 16KB to prevent watchdog timeout
+    if (offset % (16 * 1024) == 0) {
+      ESP_LOGI(TAG, "Partial refresh progress: %zu/%zu bytes (%.1f%%)", offset, remaining,
+        (float)offset * 100.0f / (float)remaining);
+      vTaskDelay(pdMS_TO_TICKS(1));
+    }
+  }
+  ESP_LOGI(TAG, "Completed SPI data transmission for partial refresh");
+  xSemaphoreGive(_spi_mutex);
+
+  // Step 5: Trigger partial display refresh (DRF)
+  epd_write_cmd(0x12);
+  // Critical delay - sample code says "!!!The delay here is necessary, 200uS at least!!!"
+  vTaskDelay(pdMS_TO_TICKS(10));
+  ESP_LOGI(TAG, "Partial refresh triggered, BUSY pin: %d", gpio_get_level(PIN_BUSY));
+
+  // Wait for refresh to complete
+  _wait_for_busy();
+
+  // Step 6: Exit partial refresh mode
+  epd_write_cmd(0x92);
+
+  ESP_LOGI(TAG, "Partial refresh complete");
+}
+
+void EInkDisplayHandler::_refresh_task(void* param) {
+  EInkDisplayHandler* handler = static_cast<EInkDisplayHandler*>(param);
+  bool perform_full_refresh = false;
+
+  ESP_LOGI(TAG, "Refresh task started");
+
+  while (true) {
+    // Wait for refresh request
+    if (xQueueReceive(handler->_refresh_queue, &perform_full_refresh, portMAX_DELAY) == pdTRUE) {
+      // Perform the requested refresh type
+      if (perform_full_refresh) {
+        ESP_LOGI(TAG, "Refresh task: Performing full refresh...");
+        handler->_perform_full_refresh(handler->_framebuffer);
+      } else {
+        ESP_LOGI(TAG, "Refresh task: Performing partial refresh...");
+        handler->_perform_partial_refresh(handler->_framebuffer);
+      }
+    }
+  }
+}
+
+void EInkDisplayHandler::_wait_for_busy() {
+  ESP_LOGI(TAG, "Waiting for display ready (BUSY pin)...");
+  int initial_level = gpio_get_level(PIN_BUSY);
+  ESP_LOGI(TAG, "Initial BUSY pin level: %d (0=BUSY, 1=FREE)", initial_level);
+
+  // If already free, no need to wait
+  if (initial_level == BUSY_INACTIVE_LEVEL) {
+    ESP_LOGI(TAG, "Display already ready (BUSY pin = 1)");
+    return;
+  }
+
+  int timeout = 0;
+  while (gpio_get_level(PIN_BUSY) == BUSY_ACTIVE_LEVEL) {  // 0=BUSY, 1=FREE
+    vTaskDelay(pdMS_TO_TICKS(100));
+    timeout++;
+    if (timeout > 100) {  // 10 second timeout
+      ESP_LOGE(TAG, "Display BUSY timeout! Pin level: %d", gpio_get_level(PIN_BUSY));
+      ESP_LOGW(TAG, "Attempting hardware reset...");
+
+      // Hardware reset sequence
+      gpio_set_level(PIN_RST, 0);
+      vTaskDelay(pdMS_TO_TICKS(10));
+      gpio_set_level(PIN_RST, 1);
+      vTaskDelay(pdMS_TO_TICKS(100));
+
+      // Re-initialize display
+      ESP_LOGI(TAG, "Re-initializing display after reset...");
+      _epd_init();
+
+      // Check if reset worked
+      int reset_timeout = 0;
+      while (gpio_get_level(PIN_BUSY) == BUSY_ACTIVE_LEVEL) {
+        vTaskDelay(pdMS_TO_TICKS(100));
+        reset_timeout++;
+        if (reset_timeout > 50) {  // 5 second timeout after reset
+          ESP_LOGE(TAG, "Display reset failed! Still busy after reset.");
+          break;
+        }
+      }
+
+      if (gpio_get_level(PIN_BUSY) != BUSY_ACTIVE_LEVEL) {
+        ESP_LOGI(TAG, "Display reset successful after %d tenths of a second", reset_timeout);
+      }
+      break;
+    }
+
+    // Log every 2 seconds to track progress
+    if (timeout % 20 == 0) {
+      ESP_LOGW(TAG, "Still waiting for BUSY pin, timeout: %d/100, level: %d",
+        timeout, gpio_get_level(PIN_BUSY));
+    }
+  }
+  ESP_LOGI(TAG, "Display ready after %d tenths of a second", timeout);
+}
+
+void EInkDisplayHandler::_convert_buffer_to_epaper(const uint8_t* lvgl_buf, uint8_t* epd_buf, size_t size) {
+  // LVGL 1-bit format is already compatible with e-paper
+  // Just copy directly
+  memcpy(epd_buf, lvgl_buf, size);
+}

main/display/eink_display_handler.h

@@ -5,9 +5,9 @@
 #include "common/semaphore_guard.h"
 #include <vector>
 #include <atomic>
-#include "epd_handler.h"
 
 // Refresh mode configuration
+#define PARTIAL_REFRESH_THRESHOLD 10  // Full refresh every N partial refreshes
 #define DISPLAY_WIDTH 800
 #define DISPLAY_HEIGHT 480
 
@@ -56,43 +56,71 @@ public:
 
   esp_err_t refresh_display(void);
   esp_err_t full_write(const uint8_t* framebuffer, const bool white_basemap = true);
-  esp_err_t partial_refresh(const uint8_t* framebuffer, const RefreshArea& area, const bool is_last_partial_update = true);
+  esp_err_t partial_refresh(const uint8_t* framebuffer, const RefreshArea& area);
   esp_err_t clear_display(void);
   esp_err_t deep_sleep_display(void);
   // Request a full refresh on next flush
   void request_full_refresh(void);
 
-  bool is_busy() {
-    return epd_handler_.is_busy();
-  }
+  // Check if display is busy (refreshing)
+  bool is_busy(void) const;
+  void wait_for_idle(void) const;
 
   esp_lcd_touch_handle_t get_touch_handle() const { return tp_handle_; }
 
+protected:
+  esp_err_t epd_write_cmd(const uint8_t cmd, uint32_t transaction_id);
+  esp_err_t epd_write_data(const uint8_t data, uint32_t transaction_id);
+  esp_err_t epd_write_cmd_with_data(const uint8_t cmd, std::vector<uint8_t>& data, uint32_t transaction_id);
+  esp_err_t transfer_spi_data(const uint8_t* data, const size_t& length, uint32_t transaction_id);
+
 private:
 
   esp_err_t init_display_pins_(void);
-  esp_err_t epd_init_internal_(uint32_t transaction_id); // full fast refresh init
+  esp_err_t epd_init_(void); // full fast refresh init
+  esp_err_t epd_init_partial_(void); // partial refresh init (standalone)
   esp_err_t epd_init_partial_internal_(uint32_t transaction_id); // partial refresh init (within existing transaction)
   esp_err_t init_touch_(void);
+  esp_err_t dangerous_epd_write_cmd_without_lock_(const uint8_t cmd);
+  esp_err_t dangerous_epd_write_data_without_lock_(const uint8_t data);
 
-  // write to the internal draw buffer
-  void write_to_buffer_(const uint8_t* src, const RefreshArea& area);
-  // write the internal draw buffer to the display's old sram
-  esp_err_t refresh_old_buffer_(uint32_t transaction_id);
+  esp_err_t begin_transaction_(TickType_t timeout, uint32_t& out_id);
+  esp_err_t end_transaction_(void);
+  // given a transaction ID, wait for current transaction to complete. The transaction ID will determine if the wait is needed.
+  esp_err_t wait_for_transaction_end_(TickType_t timeout, uint32_t awaiting_transaction_id, SemaphoreGuard& out_transaction_guard);
 
+  friend class TransactionGuard;
 
-  EPDHandler epd_handler_;
   uint32_t partial_refresh_count_ = 0;
   bool force_full_refresh_ = false;
   std::atomic<bool> is_deep_sleep_ { false };
 
+  SemaphoreHandle_t spi_mutex_ = nullptr;
+  SemaphoreHandle_t spi_transaction_mutex_ = nullptr;
   SemaphoreHandle_t refresh_mutex_ = nullptr;
+  uint32_t spi_transaction_id = 0; // For tracking SPI transactions
+  spi_device_handle_t spi_ = nullptr;
   esp_lcd_panel_io_handle_t tp_io_handle_ = nullptr;
   esp_lcd_touch_handle_t tp_handle_ = nullptr;
-
-  // this buffer reflects the current display state (1=black, 0=white)
-  uint8_t* draw_buffer_ = nullptr;
-  uint8_t* old_buffer_ = nullptr;
-  RefreshArea refresh_area_ = { 0, 0, 0, 0 };
 };
 
+
+class TransactionGuard {
+public:
+  TransactionGuard(EInkDisplayHandler& handler, TickType_t timeout = portMAX_DELAY)
+    : handler_(handler) { }
+  ~TransactionGuard() { if (transaction_id_) handler_.end_transaction_(); }
+
+  esp_err_t begin(TickType_t timeout = portMAX_DELAY) {
+    esp_err_t err = handler_.begin_transaction_(timeout, transaction_id_);
+    return err;
+  }
+  uint32_t transaction_id() const { return transaction_id_; }
+  bool is_active() const { return transaction_id_ != 0; }
+private:
+  // delete copy constructor and assignment operator
+  TransactionGuard(const TransactionGuard&) = delete;
+  TransactionGuard& operator=(const TransactionGuard&) = delete;
+  EInkDisplayHandler& handler_;
+  uint32_t transaction_id_ = 0;
+};

main/display/eink_display_handler.h.old

@@ -0,0 +1,66 @@
+#pragma once
+#include "display/display.h"
+#include "lvgl.h"
+#include "esp_lvgl_port.h"
+#include "freertos/semphr.h"
+
+// Refresh mode configuration
+#define PARTIAL_REFRESH_THRESHOLD 10  // Full refresh every N partial refreshes
+#define DISPLAY_WIDTH 800
+#define DISPLAY_HEIGHT 480
+#define DISPLAY_BUFFER_SIZE (((DISPLAY_WIDTH * DISPLAY_HEIGHT) / 8) + 8)  // 1-bit per pixel + 8-byte palette
+
+class EInkDisplayHandler : public DisplayHandler {
+public:
+  EInkDisplayHandler(EventGroupHandle_t system_event_group);
+  virtual ~EInkDisplayHandler();
+
+  void init();
+  void start_touch_task();
+
+  // Request a full refresh on next flush
+  void request_full_refresh();
+
+  // Check if display is busy (refreshing)
+  bool is_busy() const;
+
+private:
+  // LVGL display and input device handles
+  lv_display_t* _lvgl_display = nullptr;
+  lv_indev_t* _lvgl_touch_indev = nullptr;
+  lv_draw_buf_t* _lvgl_draw_buf = nullptr;
+
+  // Framebuffer
+  uint8_t* _framebuffer = nullptr;
+  bool _framebuffer_in_psram = false;
+
+  // Refresh tracking
+  uint32_t _partial_refresh_count = 0;
+  bool _force_full_refresh = false;
+  SemaphoreHandle_t _refresh_mutex = nullptr;
+
+  // Touch task
+  TaskHandle_t _touch_task_handle = nullptr;
+
+  // Refresh task and queue
+  TaskHandle_t _refresh_task_handle = nullptr;
+  QueueHandle_t _refresh_queue = nullptr;
+
+  // LVGL callbacks
+  static void _lvgl_flush_cb(lv_display_t* disp, const lv_area_t* area, uint8_t* px_map);
+  static void _lvgl_touch_read_cb(lv_indev_t* indev, lv_indev_data_t* data);
+
+  // Display operations
+  void _perform_full_refresh(const uint8_t* framebuffer);
+  void _perform_partial_refresh(const uint8_t* framebuffer);
+  void _wait_for_busy();
+
+  // Touch task
+  static void _touch_task(void* param);
+
+  // Refresh task
+  static void _refresh_task(void* param);
+
+  // Helper to convert LVGL 1-bit buffer to e-paper format
+  void _convert_buffer_to_epaper(const uint8_t* lvgl_buf, uint8_t* epd_buf, size_t size);
+};

main/display/epd_handler.cpp

@@ -1,326 +0,0 @@
-#include "display/epd_handler.h"
-#include "esp_log.h"
-#include "display/constants.h"
-#include "common/constants.h"
-#include "esp_lcd_touch_gt911.h"
-#include <driver/i2c.h>
-#define TAG "EPDHandler"
-
-#define BUSY_ACTIVE_LEVEL   0  // BUSY pin is active low
-#define BUSY_INACTIVE_LEVEL 1
-#define DMA_TRANSFER_CHUNK_SIZE 4096  // 4KB chunk size for DMA transfers
-
-EPDHandler::EPDHandler() {
-  spi_mutex_ = xSemaphoreCreateMutex();
-  if (spi_mutex_ == nullptr) {
-    ESP_LOGE(TAG, "Failed to create SPI mutex");
-  }
-  spi_transaction_mutex_ = xSemaphoreCreateMutex();
-  if (spi_transaction_mutex_ == nullptr) {
-    ESP_LOGE(TAG, "Failed to create SPI transaction mutex");
-  }
-}
-
-EPDHandler::~EPDHandler() {
-  if (spi_mutex_ != nullptr) {
-    vSemaphoreDelete(spi_mutex_);
-  }
-  if (spi_transaction_mutex_ != nullptr) {
-    vSemaphoreDelete(spi_transaction_mutex_);
-  }
-  if (spi_ != nullptr) {
-    spi_bus_remove_device(spi_);
-  }
-}
-
-esp_err_t EPDHandler::init() {
-  esp_err_t err;
-
-  // Initialize SPI bus
-  spi_bus_config_t buscfg = {};
-  buscfg.mosi_io_num = 11;  // MOSI pin
-  buscfg.miso_io_num = -1;  // No MISO for e-paper
-  buscfg.sclk_io_num = 12;  // SCK pin
-  buscfg.quadwp_io_num = -1;
-  buscfg.quadhd_io_num = -1;
-  buscfg.max_transfer_sz = DMA_TRANSFER_CHUNK_SIZE;
-
-  err = spi_bus_initialize(SPI2_HOST, &buscfg, SPI_DMA_CH_AUTO);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize SPI bus: %s", esp_err_to_name(err));
-    return err;
-  }
-
-  // Add SPI device
-  spi_device_interface_config_t devcfg = {};
-  devcfg.clock_speed_hz = 10 * 1000 * 1000;  // 10 MHz
-  devcfg.mode = 0;  // SPI mode 0
-  devcfg.spics_io_num = PIN_CS;
-  devcfg.queue_size = 7;  // Queue size for non-blocking transactions
-  devcfg.pre_cb = nullptr;
-
-  err = spi_bus_add_device(SPI2_HOST, &devcfg, &spi_);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to add SPI device: %s", esp_err_to_name(err));
-    return err;
-  }
-
-  return ESP_OK;
-}
-
-// Check if display is busy (refreshing)
-bool EPDHandler::is_busy(void) const {
-  return gpio_get_level(PIN_BUSY) != BUSY_ACTIVE_LEVEL;  // BUSY is active LOW
-}
-void EPDHandler::wait_for_idle(void) const {
-  ESP_LOGI(TAG, "Waiting for display ready (BUSY pin)...");
-  int initial_level = gpio_get_level(PIN_BUSY);
-  ESP_LOGI(TAG, "Initial BUSY pin level: %d (0=BUSY, 1=FREE)", initial_level);
-
-  // If already free, no need to wait
-  if (initial_level == BUSY_INACTIVE_LEVEL) {
-    ESP_LOGI(TAG, "Display already ready (BUSY pin = 1)");
-    return;
-  }
-  while (gpio_get_level(PIN_BUSY) != BUSY_INACTIVE_LEVEL) {
-    vTaskDelay(pdMS_TO_TICKS(10));
-  }
-  ESP_LOGI(TAG, "Display is now ready (BUSY pin = 1)");
-}
-
-esp_err_t EPDHandler::epd_write_cmd(const uint8_t cmd, uint32_t transaction_id) {
-  ESP_LOGI(TAG, "epd_write_cmd: waiting to send 0x%02X", cmd);
-
-  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
-  esp_err_t err =
-    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending cmd 0x%02X: %s",
-      cmd, esp_err_to_name(err));
-    return err;
-  }
-
-  SemaphoreGuard guard(spi_mutex_);
-  if (!guard.take(pdMS_TO_TICKS(5000))) {
-    ESP_LOGE(TAG, "SPI mutex timeout for cmd 0x%02X", cmd);
-    return ESP_ERR_TIMEOUT;
-  }
-  err = dangerous_epd_write_cmd_without_lock_(cmd);
-  ESP_LOGI(TAG, "epd_write_cmd: 0x%02X done", cmd);
-  return err;
-}
-
-esp_err_t EPDHandler::epd_write_data(const uint8_t data, uint32_t transaction_id) {
-  ESP_LOGI(TAG, "epd_write_data: waiting to send 0x%02X", data);
-  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
-  esp_err_t err =
-    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending data 0x%02X: %s",
-      data, esp_err_to_name(err));
-    return err;
-  }
-  SemaphoreGuard guard(spi_mutex_);
-  if (!guard.take(pdMS_TO_TICKS(5000))) {
-    ESP_LOGE(TAG, "SPI mutex timeout for data 0x%02X", data);
-    return ESP_ERR_TIMEOUT;
-  }
-  err = dangerous_epd_write_data_without_lock_(data);
-  ESP_LOGI(TAG, "epd_write_data: 0x%02X done", data);
-  return err;
-}
-
-esp_err_t EPDHandler::epd_write_cmd_with_data(const uint8_t cmd, std::vector<uint8_t>& data, uint32_t transaction_id) {
-  const size_t data_len = data.size();
-  ESP_LOGI(TAG, "epd_write_cmd_with_data: waiting to send cmd 0x%02X with %u bytes of data", cmd, data_len);
-
-  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
-  esp_err_t err =
-    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending cmd 0x%02X: %s, with data",
-      cmd, esp_err_to_name(err));
-    return err;
-  }
-
-  SemaphoreGuard guard(spi_mutex_);
-  if (!guard.take(pdMS_TO_TICKS(5000))) {
-    ESP_LOGE(TAG, "SPI mutex timeout for cmd with data 0x%02X", cmd);
-    return ESP_ERR_TIMEOUT;
-  }
-  err = dangerous_epd_write_cmd_without_lock_(cmd);
-  if (err != ESP_OK) {
-    return err;
-  };
-  for (size_t i = 0; i < data_len; ++i) {
-    err = dangerous_epd_write_data_without_lock_(data[i]);
-    if (err != ESP_OK) {
-      return err;
-    }
-  }
-  ESP_LOGI(TAG, "epd_write_cmd_with_data: cmd 0x%02X with %u bytes of data done", cmd, data_len);
-  return ESP_OK;
-}
-
-
-esp_err_t EPDHandler::dangerous_epd_write_cmd_without_lock_(const uint8_t cmd) {
-  ESP_LOGI(TAG, "dangerous_epd_write_cmd_without_lock_: sending 0x%02X", cmd);
-  gpio_set_level(PIN_DC, 0); // Command mode
-  spi_transaction_t t {};
-  t.length = 8;t.tx_buffer = &cmd;
-  esp_err_t err = spi_device_polling_transmit(spi_, &t);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to send data 0x%02X", cmd);
-  } else {
-    ESP_LOGI(TAG, "dangerous_epd_write_cmd_without_lock_: 0x%02X sent", cmd);
-  }
-  return err;
-}
-
-esp_err_t EPDHandler::dangerous_epd_write_data_without_lock_(const uint8_t data) {
-  ESP_LOGI(TAG, "dangerous_epd_write_data_without_lock_: sending 0x%02X", data);
-  gpio_set_level(PIN_DC, 1); // Data mode
-  spi_transaction_t t = { };
-  t.length = 8; t.tx_buffer = &data;
-  esp_err_t err = spi_device_polling_transmit(spi_, &t);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to send data 0x%02X", data);
-  } else {
-    ESP_LOGI(TAG, "dangerous_epd_write_data_without_lock_: 0x%02X sent", data);
-  }
-  return err;
-}
-
-esp_err_t EPDHandler::transfer_spi_data(const uint8_t* data, const size_t& length, uint32_t transaction_id, bool inverted) {
-  ESP_LOGI(TAG, "transfer_spi_data: waiting to send %zu bytes of data", length);
-
-  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
-  esp_err_t err =
-    wait_for_transaction_end_(pdMS_TO_TICKS(5000), transaction_id, transaction_guard);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to wait for previous transaction end before sending data of %zu bytes: %s",
-      length, esp_err_to_name(err));
-    return err;
-  }
-  SemaphoreGuard guard(spi_mutex_);
-  if (!guard.take(pdMS_TO_TICKS(5000))) {
-    ESP_LOGE(TAG, "SPI mutex timeout for data transfer of %zu bytes", length);
-    return ESP_ERR_TIMEOUT;
-  }
-  ESP_LOGI(TAG, "transfer_spi_data: starting to send %zu bytes of data", length);
-
-  size_t offset = 0;
-  size_t remaining = length;
-  gpio_set_level(PIN_DC, 1); // Data mode
-
-  // Allocate a temporary buffer for inverted data (only if inverted)
-  uint8_t* temp_transfer_buffer = nullptr;
-  if (inverted) {
-    temp_transfer_buffer = (uint8_t*)heap_caps_malloc(DMA_TRANSFER_CHUNK_SIZE, MALLOC_CAP_DMA);
-    if (temp_transfer_buffer == nullptr) {
-      ESP_LOGE(TAG, "Failed to allocate memory for inverted data transfer buffer");
-      ESP_LOGI(TAG, "Current free heap size: %u bytes", esp_get_free_heap_size());
-      ESP_LOGI(TAG, "Current free DMA-capable memory size: %u bytes",
-        heap_caps_get_free_size(MALLOC_CAP_DMA));
-      return ESP_ERR_NO_MEM;
-    }
-  }
-
-  while (remaining > 0) {
-    size_t transfer_size = (remaining < DMA_TRANSFER_CHUNK_SIZE) ? remaining : DMA_TRANSFER_CHUNK_SIZE;
-
-    const uint8_t* transfer_buffer = nullptr;
-    if (inverted) {
-      // Invert only the current chunk into the temporary buffer
-      for (size_t i = 0; i < transfer_size; ++i) {
-        temp_transfer_buffer[i] = ~data[offset + i];
-      }
-      transfer_buffer = temp_transfer_buffer;
-    } else {
-      transfer_buffer = data + offset;
-    }
-
-    spi_transaction_t t = {};
-    t.length = transfer_size * 8;  // Length in bits
-    t.tx_buffer = transfer_buffer;
-
-    esp_err_t ret = spi_device_polling_transmit(spi_, &t);
-    if (ret != ESP_OK) {
-      ESP_LOGE(TAG, "Failed to send SPI chunk at offset %zu: %s", offset, esp_err_to_name(ret));
-      if (ret == ESP_ERR_NO_MEM) {
-        ESP_LOGE(TAG, "Current free heap size: %u bytes", esp_get_free_heap_size());
-        ESP_LOGE(TAG, "Current free DMA-capable memory size: %u bytes",
-          heap_caps_get_free_size(MALLOC_CAP_DMA));
-      }
-      if (inverted && temp_transfer_buffer != nullptr) {
-        // Free the temporary inverted buffer
-        heap_caps_free(temp_transfer_buffer);
-      }
-      return ret;
-    }
-
-    remaining -= transfer_size;
-    offset += transfer_size;
-
-    // Yield every 16KB to prevent watchdog timeout
-    if (offset % (16 * 1024) == 0) {
-      ESP_LOGI(TAG, "New data progress: %zu/%zu bytes sent, yielding...", offset, length);
-      vTaskDelay(pdMS_TO_TICKS(1));
-    }
-  }
-
-  if (inverted && temp_transfer_buffer != nullptr) {
-    // Free the temporary inverted buffer
-    heap_caps_free(temp_transfer_buffer);
-  }
-
-  ESP_LOGI(TAG, "transfer_spi_data: completed sending %zu bytes of data", length);
-  return ESP_OK;
-}
-
-esp_err_t EPDHandler::begin_transaction_(TickType_t timeout, uint32_t& out_id) {
-  ESP_LOGI(TAG, "begin_transaction_: waiting to obtain transaction mutex");
-  if (xSemaphoreTake(spi_transaction_mutex_, timeout) != pdTRUE) {
-    ESP_LOGE(TAG, "begin_transaction_: transaction mutex timeout");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  out_id = ++spi_transaction_id;
-  ESP_LOGI(TAG, "begin_transaction_: transaction mutex obtained");
-  return ESP_OK;
-}
-
-esp_err_t EPDHandler::end_transaction_(void) {
-  ESP_LOGI(TAG, "end_transaction_: releasing transaction mutex");
-  if (xSemaphoreGive(spi_transaction_mutex_) != pdTRUE) {
-    ESP_LOGE(TAG, "end_transaction_: failed to release transaction mutex");
-    return ESP_FAIL;
-  }
-
-  ESP_LOGI(TAG, "end_transaction_: transaction mutex released");
-  return ESP_OK;
-}
-
-esp_err_t EPDHandler::wait_for_transaction_end_(TickType_t timeout, uint32_t awaiting_transaction_id, SemaphoreGuard& out_transaction_guard) {
-  // Validate transaction ID if provided
-  if (awaiting_transaction_id != 0 && awaiting_transaction_id != spi_transaction_id) {
-    // Invalid transaction ID
-    ESP_LOGE(TAG, "Invalid transaction ID 0x%08X while waiting, current transaction ID: 0x%08X",
-      awaiting_transaction_id, spi_transaction_id);
-    return ESP_ERR_INVALID_ARG;
-  }
-  SemaphoreGuard transaction_guard(spi_transaction_mutex_);
-  if (awaiting_transaction_id == 0) {
-    // wait for current transaction to complete
-    ESP_LOGV(TAG, "Waiting for current transaction 0x%08X to complete",
-      spi_transaction_id);
-    // take the mutex to ensure no transaction is active
-    if (!transaction_guard.take(timeout)) {
-      ESP_LOGE(TAG, "SPI transaction mutex timeout while waiting for transaction end");
-      return ESP_ERR_TIMEOUT;
-    }
-  }
-  // awaited_transaction_id is valid and matches current transaction ID or 0
-  out_transaction_guard = std::move(transaction_guard);
-  return ESP_OK;
-}

main/display/epd_handler.h

@@ -1,41 +0,0 @@
-#pragma once
-#include "freertos/FreeRTOS.h"
-#include "freertos/semphr.h"
-#include "driver/spi_master.h"
-#include "common/semaphore_guard.h"
-#include <vector>
-#include "display/transaction_guard.h"
-
-class EPDHandler : public WithTransaction {
-public:
-  EPDHandler();
-  ~EPDHandler();
-  esp_err_t init();
-
-  esp_err_t epd_write_cmd(const uint8_t cmd, uint32_t transaction_id);
-  esp_err_t epd_write_data(const uint8_t data, uint32_t transaction_id);
-  esp_err_t epd_write_cmd_with_data(const uint8_t cmd, std::vector<uint8_t>& data, uint32_t transaction_id);
-  esp_err_t transfer_spi_data(const uint8_t* data, const size_t& length, uint32_t transaction_id, bool inverted = false);
-
-  bool is_busy(void) const;
-  void wait_for_idle(void) const;
-
-private:
-
-  esp_err_t dangerous_epd_write_cmd_without_lock_(const uint8_t cmd);
-  esp_err_t dangerous_epd_write_data_without_lock_(const uint8_t data);
-
-  esp_err_t begin_transaction_(TickType_t timeout, uint32_t& out_id) override;
-  esp_err_t end_transaction_(void) override;
-  // given a transaction ID, wait for current transaction to complete. The transaction ID will determine if the wait is needed.
-  esp_err_t wait_for_transaction_end_(TickType_t timeout, uint32_t awaiting_transaction_id, SemaphoreGuard& out_transaction_guard);
-
-  spi_device_handle_t spi_ = nullptr;
-
-  SemaphoreHandle_t spi_mutex_ = nullptr;
-  SemaphoreHandle_t spi_transaction_mutex_ = nullptr;
-
-  uint32_t spi_transaction_id = 0; // For tracking SPI transactions
-
-  friend class TransactionGuard;
-};

main/display/lvgl_handler.cpp

@@ -11,7 +11,12 @@
 
 LVGLHandler::LVGLHandler(
   std::unique_ptr<EInkDisplayHandler> display_handler_in
-) : display_handler_(std::move(display_handler_in)) { }
+) : display_handler_(std::move(display_handler_in)) {
+  lvgl_mutex_ = xSemaphoreCreateMutex();
+  if (lvgl_mutex_ == nullptr) {
+    ESP_LOGE(TAG, "Failed to create LVGL mutex");
+  }
+}
 
 LVGLHandler::~LVGLHandler() {
   if (lvgl_display_ != nullptr) {
@@ -26,6 +31,14 @@ LVGLHandler::~LVGLHandler() {
     lv_draw_buf_destroy(lvgl_draw_buf_);
     lvgl_draw_buf_ = nullptr;
   }
+  if (framebuffer_ != nullptr) {
+    heap_caps_free(framebuffer_);
+    framebuffer_ = nullptr;
+  }
+  if (lvgl_mutex_ != nullptr) {
+    vSemaphoreDelete(lvgl_mutex_);
+    lvgl_mutex_ = nullptr;
+  }
 }
 
 esp_err_t LVGLHandler::initLVGL(EventGroupHandle_t system_event_group) {
@@ -90,64 +103,102 @@ void LVGLHandler::flush_cb_(lv_display_t* disp, const lv_area_t* area, uint8_t*
     return;
   }
   LVGLHandler* handler = static_cast<LVGLHandler*>(lv_display_get_user_data(disp));
-  if (handler == nullptr || handler->display_handler_ == nullptr) {
-    ESP_LOGE(TAG, "Invalid handler in flush callback");
+  if (handler == nullptr || handler->display_handler_ == nullptr || handler->framebuffer_ == nullptr) {
+    ESP_LOGE(TAG, "Invalid handler or framebuffer in flush callback");
     lv_display_flush_ready(disp);
     return;
   }
   uint8_t* pixel_data = px_map + 8; // Skip palette
   //
   ESP_LOGI(TAG, "Flush callback: x1=%d, y1=%d, x2=%d, y2=%d", area->x1, area->y1, area->x2, area->y2);
+  // take mutex
+  SemaphoreGuard guard(handler->lvgl_mutex_);
+  if (!guard.take(pdMS_TO_TICKS(5000))) {
+    ESP_LOGE(TAG, "LVGL mutex timeout in flush callback");
+    lv_display_flush_ready(disp);
+    return;
+  }
 
   // copy data to framebuffer
   int32_t area_w = lv_area_get_width(area);
   int32_t area_h = lv_area_get_height(area);
   if (area->x1 == 0 && area->y1 == 0 && area_w == DISPLAY_WIDTH && area_h == DISPLAY_HEIGHT) {
-    // revert the pixel data for e-ink (LVGL: 1=white, 0=black; E-Ink: 1=black, 0=white)
-    for (size_t i = 0; i < DISPLAY_BUFFER_SIZE; ++i) {
-      pixel_data[i] = ~pixel_data[i];
+    // Check if content actually changed before triggering expensive e-ink refresh
+    if (memcmp(handler->framebuffer_, pixel_data, DISPLAY_BUFFER_SIZE) == 0) {
+      ESP_LOGD(TAG, "Full screen flush with no changes - skipping e-ink refresh");
+      lv_display_flush_ready(disp);
+      return;
     }
-    esp_err_t err = handler->display_handler_->full_write(
-      pixel_data,
-      true  // white basemap
-    );
+    ESP_LOGI(TAG, "Full screen update");
+    memcpy(handler->framebuffer_, pixel_data, DISPLAY_BUFFER_SIZE);
+    // invert the framebuffer for e-ink display
+    for (size_t i = 0; i < DISPLAY_BUFFER_SIZE; ++i) {
+      handler->framebuffer_[i] = ~handler->framebuffer_[i];
+    }
+    // request full refresh
+    esp_err_t err = handler->display_handler_->full_write(handler->framebuffer_, true);
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Full refresh request failed: %s", esp_err_to_name(err));
     }
   } else {
     // partial update
     ESP_LOGI(TAG, "Partial update: x1=%d, y1=%d, w=%d, h=%d", area->x1, area->y1, area_w, area_h);
+    // update the framebuffer with the partial data
+    for (int32_t row = 0; row < area_h; ++row) {
+      int32_t fb_y = area->y1 + row;
+      int32_t fb_x_byte_start = area->x1 / 8;
+      int32_t fb_x_byte_end = area->x2 / 8;
+      uint8_t* fb_ptr = &handler->framebuffer_[fb_y * (DISPLAY_WIDTH / 8) + fb_x_byte_start];
+      const uint8_t* src_ptr = &pixel_data[row * (area_w / 8)];
+      // invert the partial framebuffer data for e-ink display
+      for (int32_t i = 0; i < (fb_x_byte_end - fb_x_byte_start + 1); ++i) {
+        fb_ptr[i] = ~src_ptr[i];
+      }
+    }
+    // update the refresh area
+    handler->refresh_area_.expand_to_include(area->x1, area->y1, area->x2, area->y2);
+    //
 
-    // Prepare partial buffer
-    const uint32_t area_width_bytes = (area->x2 - area->x1 + 1) / 8;
-    const uint32_t area_height = area->y2 - area->y1 + 1;
-    const size_t partial_buffer_size = area_width_bytes * area_height;
-    uint8_t* partial_buffer = new uint8_t[partial_buffer_size];
+    if (lv_display_flush_is_last(disp) && !handler->refresh_area_.is_empty()) {
+      ESP_LOGI(TAG, "Last flush in batch - performing partial refresh");
+      ESP_LOGI(TAG, "Refresh area: x1=%d, y1=%d, x2=%d, y2=%d",
+        handler->refresh_area_.x1, handler->refresh_area_.y1,
+        handler->refresh_area_.x2, handler->refresh_area_.y2);
+      // copy the area to refresh
+      uint8_t* partial_buffer = new uint8_t[handler->refresh_area_.area() / 8];
       if (partial_buffer == nullptr) {
-      ESP_LOGE(TAG, "Failed to allocate partial buffer for flush callback");
+        ESP_LOGE(TAG, "Failed to allocate partial buffer for refresh");
         lv_display_flush_ready(disp);
         return;
       }
-    // Copy pixel data to partial buffer and invert for e-ink
-    for (int32_t row = 0; row < area_height; ++row) {
-      for (int32_t col = 0; col < area_width_bytes; ++col) {
-        size_t src_index = row * area_width_bytes + col;
-        partial_buffer[src_index] = ~pixel_data[src_index];
+      // loop the refresh area and copy data
+      uint32_t x1 = handler->refresh_area_.x1;
+      uint32_t x2 = handler->refresh_area_.x2;
+      uint32_t y1 = handler->refresh_area_.y1;
+      uint32_t y2 = handler->refresh_area_.y2;
+      uint32_t height = y2 - y1 + 1;
+      uint32_t width = x2 - x1 + 1;
+
+      for (uint32_t row = 0; row < height; ++row) {
+        uint32_t fb_y = y1 + row;
+        uint32_t fb_x_byte_start = x1 / 8;
+        uint32_t fb_x_byte_end = x2 / 8;
+        uint8_t* fb_ptr = &handler->framebuffer_[fb_y * (DISPLAY_WIDTH / 8) + fb_x_byte_start];
+        uint8_t* dest_ptr = &partial_buffer[row * (width / 8)];
+        for (uint32_t i = 0; i < (fb_x_byte_end - fb_x_byte_start + 1); ++i) {
+          dest_ptr[i] = ~fb_ptr[i];
         }
       }
 
       esp_err_t err = handler->display_handler_->partial_refresh(partial_buffer,
-      RefreshArea {
-        area->x1,
-        area->y1,
-        area->x2,
-        area->y2
-      }, lv_display_flush_is_last(disp));
+        handler->refresh_area_);
       delete[] partial_buffer;
 
       if (err != ESP_OK) {
         ESP_LOGE(TAG, "Partial refresh request failed: %s", esp_err_to_name(err));
       }
+      handler->refresh_area_.reset();
+    }
   }
   //
   lv_display_flush_ready(disp);
@@ -183,7 +234,7 @@ void LVGLHandler::touch_read_cb_(lv_indev_t* indev, lv_indev_data_t* data) {
     esp_lcd_touch_get_data(tp_handle, point_data, &touch_cnt, 1);
 
     if (touch_cnt > 0) {
-      // ESP_LOGI(TAG, "Touch data read successfully: x=%d, y=%d", point_data[0].x, point_data[0].y);
+      ESP_LOGI(TAG, "Touch data read successfully: x=%d, y=%d", point_data[0].x, point_data[0].y);
       data->point.x = point_data[0].x;
       data->point.y = point_data[0].y;
       data->state = LV_INDEV_STATE_PRESSED;
@@ -217,10 +268,31 @@ esp_err_t LVGLHandler::initLVGLDisplay_() {
     return ESP_FAIL;
   }
 
+  // set framebuffer
+  framebuffer_ = (uint8_t*)heap_caps_malloc(LVGL_BUFFER_SIZE, MALLOC_CAP_SPIRAM);
+  if (framebuffer_ != nullptr) {
+    framebuffer_in_psram_ = true;
+    ESP_LOGI(TAG, "Framebuffer allocated in PSRAM (%zu bytes)", LVGL_BUFFER_SIZE);
+  } else {
+    ESP_LOGW(TAG, "PSRAM not available, allocating framebuffer in internal RAM");
+    framebuffer_ = (uint8_t*)heap_caps_malloc(LVGL_BUFFER_SIZE, MALLOC_CAP_INTERNAL);
+    framebuffer_in_psram_ = false;
+    if (framebuffer_ == nullptr) {
+      ESP_LOGE(TAG, "Failed to allocate framebuffer");
+      lv_display_delete(lvgl_display_);
+      lvgl_display_ = nullptr;
+      lvgl_port_unlock();
+      return ESP_FAIL;
+    }
+    ESP_LOGI(TAG, "Framebuffer allocated in internal RAM (%zu bytes)", LVGL_BUFFER_SIZE);
+  }
+  memset(framebuffer_, 0xFF, LVGL_BUFFER_SIZE);  // Initialize to white
   // Create a draw buffer covering the entire display
   lvgl_draw_buf_ = lv_draw_buf_create(DISPLAY_WIDTH, DISPLAY_HEIGHT, LV_COLOR_FORMAT_I1, LV_STRIDE_AUTO);
   if (lvgl_draw_buf_ == nullptr) {
     ESP_LOGE(TAG, "Failed to create LVGL draw buffer");
+    heap_caps_free(framebuffer_);
+    framebuffer_ = nullptr;
     lv_display_delete(lvgl_display_);
     lvgl_display_ = nullptr;
     lvgl_port_unlock();

main/display/lvgl_handler.h

@@ -31,4 +31,10 @@ private:
   lv_display_t* lvgl_display_ = nullptr;
   lv_indev_t* lvgl_touch_indev_ = nullptr;
   lv_draw_buf_t* lvgl_draw_buf_ = nullptr;
+  uint8_t* framebuffer_ = nullptr;
+  bool framebuffer_in_psram_ = false;
+  RefreshArea refresh_area_ = { 0, 0, 0, 0 };
+
+
+  SemaphoreHandle_t lvgl_mutex_ = nullptr;
 };

main/display/transaction_guard.h

@@ -1,33 +0,0 @@
-#pragma once
-#include "freertos/FreeRTOS.h"
-#include "freertos/semphr.h"
-#include <esp_err.h>
-#include <type_traits>
-
-class WithTransaction {
-protected:
-  virtual esp_err_t end_transaction_() = 0;
-  virtual esp_err_t begin_transaction_(TickType_t timeout, uint32_t& out_id) = 0;
-
-  friend class TransactionGuard;
-};
-
-class TransactionGuard {
-public:
-  TransactionGuard(WithTransaction& handler, TickType_t timeout = portMAX_DELAY)
-    : handler_(handler) { }
-  ~TransactionGuard() { if (transaction_id_) handler_.end_transaction_(); }
-
-  esp_err_t begin(TickType_t timeout = portMAX_DELAY) {
-    esp_err_t err = handler_.begin_transaction_(timeout, transaction_id_);
-    return err;
-  }
-  uint32_t transaction_id() const { return transaction_id_; }
-  bool is_active() const { return transaction_id_ != 0; }
-private:
-  // delete copy constructor and assignment operator
-  TransactionGuard(const TransactionGuard&) = delete;
-  TransactionGuard& operator=(const TransactionGuard&) = delete;
-  WithTransaction& handler_;
-  uint32_t transaction_id_ = 0;
-};

main/idf_component.yml

@@ -18,4 +18,3 @@ dependencies:
   espressif/esp_lcd_touch_gt911: ^1.2.0~1
   espressif/esp_lvgl_port: ^2.7.0
   espressif/cjson: ^1.7.19
-  joltwallet/littlefs: ==1.20.3

main/info/info.cpp

@@ -23,8 +23,7 @@ void display_chip_info() {
     (chip_info.features & CHIP_FEATURE_BLE) ? "BLE" : "",
     (chip_info.features & CHIP_FEATURE_IEEE802154) ? ", 802.15.4 (Zigbee/Thread), " : "",
     // psram
-    (chip_info.features & CHIP_FEATURE_EMB_PSRAM) ? "with embedded PSRAM, " : ""
-  );
+    (chip_info.features & CHIP_FEATURE_EMB_PSRAM) ? "with embedded PSRAM, " : "");
 
   unsigned major_rev = chip_info.revision / 100;
   unsigned minor_rev = chip_info.revision % 100;
@@ -40,8 +39,5 @@ void display_chip_info() {
   printf("Minimum free heap size: %" PRIu32 " bytes\n", esp_get_minimum_free_heap_size());
   // psram
   printf("PSRAM size: %u bytes\n", esp_psram_get_size());
-  // dma size
-  printf("DMA-capable memory size: %u bytes\n", heap_caps_get_free_size(MALLOC_CAP_DMA));
-  printf("DMA-capable internal memory size: %u bytes\n", heap_caps_get_free_size(MALLOC_CAP_DMA | MALLOC_CAP_INTERNAL));
 
 }

main/io/fs_handler.cpp

@@ -1,552 +0,0 @@
-#include "io/fs_handler.h"
-#include <sys/stat.h>
-#include <dirent.h>
-#include <errno.h>
-#include <cstring>
-#include "esp_partition.h"
-
-#define TAG "LittleFSHandler"
-#define PARTITION_LABEL "storage"
-#define BLOCK_SIZE 512  // Match typical flash sector size
-
-//
-// FSGuard implementation
-//
-
-FSGuard::FSGuard(LittleFSHandler* fs_handler, const std::string& relative_path, const char* flags)
-  : fs_handler_(fs_handler), file_(nullptr) {
-  if (fs_handler_ != nullptr) {
-    fs_handler_->open_file_(relative_path, flags, file_);
-  } else {
-    ESP_LOGE("FSGuard", "FSGuard initialized with null LittleFSHandler");
-  }
-}
-
-FSGuard::~FSGuard() {
-  this->close();
-}
-
-esp_err_t FSGuard::close() {
-  if (file_ != nullptr && fs_handler_ != nullptr) {
-    esp_err_t err = fs_handler_->close_file_(file_);
-    file_ = nullptr;
-    fs_handler_ = nullptr;
-    if (err != ESP_OK) {
-      ESP_LOGE("FSGuard", "Error closing file: %s", esp_err_to_name(err));
-    }
-    return err;
-  }
-  return ESP_OK;
-}
-
-//
-// LittleFSHandler implementation
-//
-
-LittleFSHandler::LittleFSHandler() {
-  this->fs_mutex_ = xSemaphoreCreateMutex();
-  if (this->fs_mutex_ == nullptr) {
-    ESP_LOGE(TAG, "Failed to create filesystem mutex");
-  }
-}
-
-LittleFSHandler::~LittleFSHandler() {
-  if (this->is_initialized_()) {
-    esp_vfs_littlefs_unregister(PARTITION_LABEL);
-    this->initialized_ = false;
-  }
-  if (this->fs_mutex_ != nullptr) {
-    vSemaphoreDelete(this->fs_mutex_);
-    this->fs_mutex_ = nullptr;
-  }
-}
-
-esp_err_t LittleFSHandler::init(std::string base_path) {
-  // default config
-  esp_vfs_littlefs_conf_t config = {};
-  config.dont_mount = false;
-  config.partition_label = PARTITION_LABEL;
-  config.base_path = base_path.c_str();
-  config.format_if_mount_failed = true;
-  //
-  base_path_ = base_path;
-  return init(config);
-}
-
-esp_err_t LittleFSHandler::init(const esp_vfs_littlefs_conf_t& config) {
-  base_path_ = std::string(config.base_path);
-  if (this->is_initialized_()) {
-    ESP_LOGW(TAG, "LittleFS already initialized, skipping");
-    return ESP_OK;
-  }
-
-  esp_err_t err = esp_vfs_littlefs_register(&config);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize LittleFS: %s", esp_err_to_name(err));
-
-    if (err == ESP_ERR_NOT_FOUND) {
-      ESP_LOGE(TAG, "Listing all available partitions:");
-      esp_partition_iterator_t it = esp_partition_find(ESP_PARTITION_TYPE_ANY, ESP_PARTITION_SUBTYPE_ANY, NULL);
-      while (it != NULL) {
-        const esp_partition_t* part = esp_partition_get(it);
-        ESP_LOGE(TAG, "  - Label: '%s', Type: 0x%02x, Subtype: 0x%02x, Address: 0x%08x, Size: 0x%08x",
-          part->label, part->type, part->subtype, part->address, part->size);
-        it = esp_partition_next(it);
-      }
-      esp_partition_iterator_release(it);
-    }
-
-    return ESP_ERR_INVALID_STATE;
-  }
-  this->initialized_ = true;
-  return ESP_OK;
-}
-
-std::string LittleFSHandler::get_base_path() const {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized, cannot get base path");
-    return "";
-  }
-  return base_path_;
-}
-
-std::string LittleFSHandler::get_full_path(const std::string& relative_path) const {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized, cannot get full path");
-    return "";
-  }
-  return base_path_ + "/" + relative_path;
-}
-
-esp_err_t LittleFSHandler::write_file(const std::string& relative_path, const uint8_t* data, size_t size, size_t& out_bytes_written) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-  if (data == nullptr) {
-    ESP_LOGE(TAG, "Data pointer is null");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  // Try to open with r+b first to preserve existing content for comparison
-  FSGuard file_guard(this, relative_path, "r+b");
-
-  // If file doesn't exist, open with wb
-  if (!file_guard.is_open()) {
-    FSGuard new_file_guard(this, relative_path, "wb");
-    if (!new_file_guard.is_open()) {
-      return ESP_ERR_NOT_FOUND;
-    }
-    return this->write_if_different_(new_file_guard.get_file(), data, size, out_bytes_written);
-  }
-  return this->write_if_different_(file_guard.get_file(), data, size, out_bytes_written);
-}
-
-
-// Caller is responsible for opening the file in appropriate mode
-// If the file doesn't exist, use write_file with "wb" mode
-// If the file exists, use "r+b" mode to read and write
-esp_err_t LittleFSHandler::write_file(FILE* file, const uint8_t* data, size_t size, size_t& out_bytes_written) {
-  return this->write_if_different_(file, data, size, out_bytes_written);
-}
-
-esp_err_t LittleFSHandler::append_file(const std::string& relative_path, const uint8_t* data, size_t size, size_t& out_bytes_written) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-  if (data == nullptr) {
-    ESP_LOGE(TAG, "Data pointer is null");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  FSGuard file_guard(this, relative_path, "ab");
-  FILE* file = file_guard.get_file();
-  if (file == nullptr) {
-    return ESP_ERR_NOT_FOUND;
-  }
-  return this->append_file(file, data, size, out_bytes_written);
-}
-
-esp_err_t LittleFSHandler::append_file(FILE* file, const uint8_t* data, size_t size, size_t& out_bytes_written) {
-  if (file == nullptr) {
-    ESP_LOGE(TAG, "File pointer is null");
-    return ESP_ERR_INVALID_ARG;
-  }
-  if (data == nullptr) {
-    ESP_LOGE(TAG, "Data pointer is null");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  if (fseek(file, 0, SEEK_END) != 0) {
-    ESP_LOGE(TAG, "Failed to seek to end of file");
-    return ESP_ERR_INVALID_STATE;
-  }
-  // write data with POSIX
-  size_t bytes_written = fwrite(data, 1, size, file);
-  if (bytes_written != size) {
-    ESP_LOGE(TAG, "Failed to write all data to file, expected %zu bytes, wrote %zu bytes", size, bytes_written);
-    return ESP_ERR_NO_MEM;
-  }
-  if (fflush(file) != 0) {
-    ESP_LOGE(TAG, "Failed to flush file");
-    return ESP_ERR_INVALID_STATE;
-  }
-  out_bytes_written = bytes_written;
-  return ESP_OK;
-}
-
-esp_err_t LittleFSHandler::read_file(const std::string& relative_path, const size_t max_size, uint8_t* out_data, size_t& out_size) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-  if (out_data == nullptr) {
-    ESP_LOGE(TAG, "Output data pointer is null");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  FSGuard file_guard(this, relative_path, "rb");
-  FILE* file = file_guard.get_file();
-  if (file == nullptr) {
-    return ESP_ERR_NOT_FOUND;
-  }
-  return this->read_file(file, max_size, out_data, out_size);
-}
-
-esp_err_t LittleFSHandler::read_file(FILE* file, const size_t max_size, uint8_t* out_data, size_t& out_size) {
-  if (file == nullptr) {
-    ESP_LOGE(TAG, "File pointer is null");
-    return ESP_ERR_INVALID_ARG;
-  }
-  if (out_data == nullptr) {
-    ESP_LOGE(TAG, "Output data pointer is null");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  size_t bytes_read = fread(out_data, 1, max_size, file);
-  if (bytes_read == 0 && ferror(file)) {
-    ESP_LOGE(TAG, "Failed to read from file");
-    return ESP_ERR_INVALID_STATE;
-  }
-  out_size = bytes_read;
-  return ESP_OK;
-}
-
-esp_err_t LittleFSHandler::delete_file(const std::string& relative_path) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  std::string full_path = this->get_full_path(relative_path);
-  if (remove(full_path.c_str()) != 0) {
-    ESP_LOGE(TAG, "Failed to delete file %s: %s", full_path.c_str(), strerror(errno));
-    return ESP_ERR_NOT_FOUND;
-  }
-  return ESP_OK;
-}
-
-bool LittleFSHandler::file_exists(const std::string& relative_path) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return false;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return false;
-  }
-
-  std::string full_path = this->get_full_path(relative_path);
-  struct stat st;
-  return (stat(full_path.c_str(), &st) == 0 && S_ISREG(st.st_mode));
-}
-
-esp_err_t LittleFSHandler::get_file_size(const std::string& relative_path, size_t& out_size) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  std::string full_path = this->get_full_path(relative_path);
-  struct stat st;
-  if (stat(full_path.c_str(), &st) != 0) {
-    ESP_LOGE(TAG, "Failed to stat file %s", full_path.c_str());
-    return ESP_ERR_NOT_FOUND;
-  }
-  out_size = st.st_size;
-  return ESP_OK;
-}
-
-esp_err_t LittleFSHandler::create_directory(const std::string& relative_path) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  std::string full_path = this->get_full_path(relative_path);
-  if (mkdir(full_path.c_str(), 0755) != 0) {
-    if (errno == EEXIST) {
-      ESP_LOGW(TAG, "Directory %s already exists", full_path.c_str());
-      return ESP_OK;
-    }
-    ESP_LOGE(TAG, "Failed to create directory %s: %s", full_path.c_str(), strerror(errno));
-    return ESP_ERR_INVALID_STATE;
-  }
-  return ESP_OK;
-}
-
-esp_err_t LittleFSHandler::list_directory(const std::string& relative_path, std::vector<std::string>& out_entries) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  SemaphoreGuard guard(this->fs_mutex_);
-  if (guard.take() != pdTRUE) {
-    ESP_LOGE(TAG, "Failed to acquire filesystem mutex");
-    return ESP_ERR_TIMEOUT;
-  }
-
-  std::string full_path = this->get_full_path(relative_path);
-  DIR* dir = opendir(full_path.c_str());
-  if (dir == nullptr) {
-    ESP_LOGE(TAG, "Failed to open directory %s", full_path.c_str());
-    return ESP_ERR_NOT_FOUND;
-  }
-
-  out_entries.clear();
-  struct dirent* entry;
-  while ((entry = readdir(dir)) != nullptr) {
-    // Skip . and ..
-    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
-      continue;
-    }
-    out_entries.push_back(entry->d_name);
-  }
-  closedir(dir);
-  return ESP_OK;
-}
-
-//
-// Private methods
-//
-
-esp_err_t LittleFSHandler::open_file_(const std::string& relative_path, const char* flags, FILE*& out_file) {
-  if (!this->is_initialized_()) {
-    ESP_LOGE(TAG, "LittleFS is not initialized, cannot open file");
-    return ESP_ERR_INVALID_STATE;
-  }
-  std::string full_path = this->get_full_path(relative_path);
-  FILE* file = fopen(full_path.c_str(), flags);
-  if (file == nullptr) {
-    // Use debug level if file doesn't exist (ENOENT), warning level for other errors
-    if (errno == ENOENT) {
-      ESP_LOGD(TAG, "File %s does not exist (flags %s)", full_path.c_str(), flags);
-    } else {
-      ESP_LOGW(TAG, "Failed to open file %s with flags %s: %s", full_path.c_str(), flags, strerror(errno));
-    }
-    return ESP_ERR_NOT_FOUND;
-  }
-  out_file = file;
-  return ESP_OK;
-}
-
-esp_err_t LittleFSHandler::close_file_(FILE* file) {
-  if (file == nullptr) {
-    return ESP_OK;
-  }
-  if (fclose(file) != 0) {
-    ESP_LOGE(TAG, "Failed to close file: %s", strerror(errno));
-    return ESP_ERR_INVALID_STATE;
-  }
-  return ESP_OK;
-}
-
-esp_err_t LittleFSHandler::write_if_different_(FILE* file, const uint8_t* data, size_t size) {
-  size_t out_bytes_written = 0;
-  return this->write_if_different_(file, data, size, out_bytes_written);
-}
-
-esp_err_t LittleFSHandler::write_if_different_(FILE* file, const uint8_t* data, size_t size, size_t& out_bytes_written) {
-  if (file == nullptr || data == nullptr) {
-    ESP_LOGE(TAG, "Invalid parameters");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  // Get existing file size
-  if (fseek(file, 0, SEEK_END) != 0) {
-    ESP_LOGE(TAG, "Failed to seek to end of file");
-    return ESP_ERR_INVALID_STATE;
-  }
-  long file_size_long = ftell(file);
-  if (file_size_long < 0) {
-    ESP_LOGE(TAG, "Failed to get file size");
-    return ESP_ERR_INVALID_STATE;
-  }
-  size_t file_size = (size_t)file_size_long;
-
-  if (fseek(file, 0, SEEK_SET) != 0) {
-    ESP_LOGE(TAG, "Failed to seek to beginning of file");
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  out_bytes_written = 0;
-  size_t compare_size = (file_size < size) ? file_size : size;
-
-  // Read entire file content for comparison
-  std::vector<uint8_t> existing_data;
-  if (file_size > 0) {
-    existing_data.resize(file_size);
-    size_t bytes_read = fread(existing_data.data(), 1, file_size, file);
-    if (bytes_read != file_size) {
-      ESP_LOGE(TAG, "Failed to read existing file data");
-      return ESP_ERR_INVALID_STATE;
-    }
-  }
-
-  // Compare and identify blocks that need updating
-  std::vector<bool> block_needs_update((size + BLOCK_SIZE - 1) / BLOCK_SIZE, false);
-  bool any_changes = false;
-
-  for (size_t offset = 0; offset < compare_size; offset += BLOCK_SIZE) {
-    size_t chunk_size = BLOCK_SIZE;
-    if (offset + chunk_size > compare_size) {
-      chunk_size = compare_size - offset;
-    }
-
-    if (memcmp(existing_data.data() + offset, data + offset, chunk_size) != 0) {
-      block_needs_update[offset / BLOCK_SIZE] = true;
-      any_changes = true;
-    }
-  }
-
-  // Check if size changed or there are additional blocks to write
-  if (size != file_size) {
-    any_changes = true;
-  }
-
-  if (!any_changes) {
-    ESP_LOGD(TAG, "File content unchanged, skipping write");
-    return ESP_OK;
-  }
-
-  // Seek to beginning to start writing
-  if (fseek(file, 0, SEEK_SET) != 0) {
-    ESP_LOGE(TAG, "Failed to seek to beginning for writing");
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  // Write only changed blocks
-  for (size_t offset = 0; offset < compare_size; offset += BLOCK_SIZE) {
-    size_t block_index = offset / BLOCK_SIZE;
-    if (!block_needs_update[block_index]) {
-      // Skip unchanged block
-      if (fseek(file, offset + BLOCK_SIZE, SEEK_SET) != 0) {
-        // If at end of compare region, this is OK
-        if (offset + BLOCK_SIZE > compare_size) {
-          if (fseek(file, compare_size, SEEK_SET) != 0) {
-            ESP_LOGE(TAG, "Failed to seek past unchanged block");
-            return ESP_ERR_INVALID_STATE;
-          }
-        } else {
-          ESP_LOGE(TAG, "Failed to seek past unchanged block at %zu", offset);
-          return ESP_ERR_INVALID_STATE;
-        }
-      }
-      continue;
-    }
-
-    size_t chunk_size = BLOCK_SIZE;
-    if (offset + chunk_size > compare_size) {
-      chunk_size = compare_size - offset;
-    }
-
-    if (fseek(file, offset, SEEK_SET) != 0) {
-      ESP_LOGE(TAG, "Failed to seek to offset %zu", offset);
-      return ESP_ERR_INVALID_STATE;
-    }
-
-    size_t written = fwrite(data + offset, 1, chunk_size, file);
-    if (written != chunk_size) {
-      ESP_LOGE(TAG, "Failed to write block at offset %zu", offset);
-      return ESP_ERR_INVALID_STATE;
-    }
-    out_bytes_written += written;
-  }
-
-  // Handle size differences
-  if (size > file_size) {
-    // Write additional data beyond original file size
-    if (fseek(file, file_size, SEEK_SET) != 0) {
-      ESP_LOGE(TAG, "Failed to seek to end for appending");
-      return ESP_ERR_INVALID_STATE;
-    }
-    size_t written = fwrite(data + file_size, 1, size - file_size, file);
-    if (written != (size - file_size)) {
-      ESP_LOGE(TAG, "Failed to write additional data");
-      return ESP_ERR_INVALID_STATE;
-    }
-    out_bytes_written += written;
-  } else if (size < file_size) {
-    // Truncate file to new size
-    if (ftruncate(fileno(file), size) != 0) {
-      ESP_LOGE(TAG, "Failed to truncate file to size %zu", size);
-      return ESP_ERR_INVALID_STATE;
-    }
-  }
-
-  // Flush to ensure data is written to storage
-  if (fflush(file) != 0) {
-    ESP_LOGE(TAG, "Failed to flush file after write");
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  return ESP_OK;
-}
-
-bool LittleFSHandler::is_initialized_() const {
-  return this->initialized_;
-}
-
-
-
-

main/io/fs_handler.h

@@ -1,95 +0,0 @@
-#pragma once
-#include "freertos/FreeRTOS.h"
-#include "freertos/semphr.h"
-#include "esp_littlefs.h"
-#include "esp_err.h"
-#include <string>
-#include <vector>
-#include <map>
-#include <memory>
-#include "esp_log.h"
-#include <semaphore_guard.h>
-
-// Forward declaration
-class LittleFSHandler;
-
-class FSGuard {
-public:
-  FSGuard(LittleFSHandler* fs_handler, const std::string& relative_path, const char* flags);
-  ~FSGuard();
-
-  esp_err_t close();
-
-  FILE* get_file() {
-    return file_;
-  }
-
-  bool is_open() const {
-    return file_ != nullptr;
-  }
-
-private:
-  LittleFSHandler* fs_handler_ = nullptr;
-  FILE* file_;
-
-  // prevent copying and moving
-  FSGuard(const FSGuard&) = delete;
-  FSGuard& operator=(const FSGuard&) = delete;
-  FSGuard(FSGuard&& other) = delete;
-  FSGuard& operator=(FSGuard&& other) = delete;
-};
-
-//LittleFSHandler interface
-// All paths are relative to the mounted filesystem root
-// Implementations should handle initialization of the filesystem, and mounting if necessary
-// When destroyed, implementations should unmount the filesystem if necessary
-// All paths are relative to the mounted filesystem root, e.g. if mounted at /littlefs, and file is /data.txt, the full path is /littlefs/data.txt
-// File operations use standard C FILE* wrapped in FSGuard for RAII
-class LittleFSHandler {
-public:
-  LittleFSHandler();
-  ~LittleFSHandler();
-
-  esp_err_t init(std::string base_path);
-  esp_err_t init(const esp_vfs_littlefs_conf_t& config);
-  std::string get_base_path() const;
-  std::string get_full_path(const std::string& relative_path) const;
-  // File operations
-  esp_err_t write_file(const std::string& relative_path, const uint8_t* data, size_t size, size_t& out_bytes_written);
-  esp_err_t write_file(FILE* file, const uint8_t* data, size_t size, size_t& out_bytes_written);
-  //
-  esp_err_t append_file(const std::string& relative_path, const uint8_t* data, size_t size, size_t& out_bytes_written);
-  esp_err_t append_file(FILE* file, const uint8_t* data, size_t size, size_t& out_bytes_written);
-  //
-  esp_err_t read_file(const std::string& relative_path, const size_t max_size, uint8_t* out_data, size_t& out_size);
-  esp_err_t read_file(FILE* file, const size_t max_size, uint8_t* out_data, size_t& out_size);
-  //
-  esp_err_t delete_file(const std::string& relative_path);
-  //
-  bool file_exists(const std::string& relative_path);
-  esp_err_t get_file_size(const std::string& relative_path, size_t& out_size);
-  // Directory operations
-  esp_err_t create_directory(const std::string& relative_path);
-  esp_err_t list_directory(const std::string& relative_path, std::vector<std::string>& out_entries);
-
-protected:
-
-  esp_err_t open_file_(const std::string& relative_path, const char* flags, FILE*& out_file);
-  esp_err_t close_file_(FILE* file);
-
-  // uses standard C FILE* for file operations
-  esp_err_t write_if_different_(FILE* file, const uint8_t* data, size_t size);
-  esp_err_t write_if_different_(FILE* file, const uint8_t* data, size_t size, size_t& out_bytes_written);
-
-  friend class FSGuard;
-
-private:
-  //
-  bool is_initialized_() const;
-
-  SemaphoreHandle_t fs_mutex_ = nullptr;
-  bool initialized_ = false;
-  std::string base_path_;
-};
-
-

main/io/nvs_handler.cpp

@@ -20,7 +20,6 @@ NVSStorageHandler::~NVSStorageHandler() {
 void NVSStorageHandler::init(const EventGroupHandle_t& system_event_group) {
   esp_err_t err = nvs_flash_init();
   if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
-    ESP_LOGW(TAG, "NVS Flash init failed with %s, erasing and retrying...", esp_err_to_name(err));
     nvs_flash_erase();
     err = nvs_flash_init();
   }
@@ -44,26 +43,11 @@ void NVSStorageHandler::put(const std::string& key, const std::string& value) {
   }
 
   esp_err_t err = nvs_set_str(this->nvsHandle, key.c_str(), value.c_str());
-  if (err == ESP_ERR_NVS_NOT_ENOUGH_SPACE) {
-    ESP_LOGE(TAG, "NVS storage full! Cannot store key '%s'. Consider clearing old data.", key.c_str());
-    ESP_LOGI(TAG, "Attempting to erase and retry...");
-    // Try to commit pending changes first
-    nvs_commit(this->nvsHandle);
-    // Retry once
-    err = nvs_set_str(this->nvsHandle, key.c_str(), value.c_str());
   if (err != ESP_OK) {
-      ESP_LOGE(TAG, "Retry failed: %s", esp_err_to_name(err));
-      return;
-    }
-  } else if (err != ESP_OK) {
     ESP_LOGE(TAG, "Error (%s) setting key-value pair in NVS!", esp_err_to_name(err));
-    return;
-  }
-
-  // Commit successful write
-  err = nvs_commit(this->nvsHandle);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Error (%s) committing to NVS!", esp_err_to_name(err));
+  } else {
+    nvs_commit(this->nvsHandle);
+    // ESP_LOGI(TAG, "Key-value pair (%s, %s) stored in NVS.", key.c_str(), value.c_str());
   }
 }
 

main/main.cpp

@@ -13,12 +13,14 @@
 #include "common/constants.h"
 #include "common/queue_defs.h"
 #include "io/nvs_handler.h"
-#include "io/fs_handler.h"
 #include "info/info.h"
 #include "display/eink_display_handler.h"
 #include "display/lvgl_handler.h"
 #include "ui/ui_handler.h"
-#include "ui/apps/registry.h"
+#include "ui/app_registry.h"
+#include "ui/apps/shutdown_app.h"
+#include "ui/apps/discord_app.h"
+#include "ui/apps/mtr_app.h"
 #include <tick/lv_tick.h>
 #include "esp_lvgl_port.h"
 #include "lvgl.h"
@@ -29,6 +31,7 @@
 
 // nvs storage namespaces, 15 characters max
 #define DEFAULT_STORAGE_NAMESPACE "storage"
+#define WIFI_CREDENTIALS_STORAGE_NAMESPACE "wifi_cred"
 #define TAG "Main"
 
 extern "C" void app_main(void);
@@ -39,6 +42,221 @@ void init_queues(
   EventGroupHandle_t& system_lifecycle_event_group
 );
 
+
+
+void EInk_Checkerboard(
+  EInkDisplayHandler* display_handler
+) {
+  struct CheckerboardTaskParams {
+    EInkDisplayHandler* display_handler;
+  };
+  auto checkerboard_task_fn = [](void* pvParameters) {
+    CheckerboardTaskParams* params = static_cast<CheckerboardTaskParams*>(pvParameters);
+    if (params != nullptr && params->display_handler != nullptr) {
+      // Add this task to the watchdog timer
+      esp_err_t wdt_err = esp_task_wdt_add(NULL);
+      if (wdt_err != ESP_OK) {
+        ESP_LOGW(TAG, "Failed to add checkerboard task to watchdog: %s", esp_err_to_name(wdt_err));
+      }
+
+      EInkDisplayHandler* display_handler = params->display_handler;
+      const size_t DISPLAY_BUFFER_SIZE = DISPLAY_WIDTH * DISPLAY_HEIGHT / 8;
+      uint8_t* framebuffer = new uint8_t[DISPLAY_BUFFER_SIZE];
+      if (framebuffer == nullptr) {
+        ESP_LOGE(TAG, "Failed to allocate framebuffer for checkerboard task");
+        if (wdt_err == ESP_OK) {
+          esp_task_wdt_delete(NULL);
+        }
+        vTaskDelete(NULL);
+        return;
+      }
+      // Create checkerboard pattern
+      for (size_t y = 0; y < DISPLAY_HEIGHT; y++) {
+        for (size_t x = 0; x < DISPLAY_WIDTH; x++) {
+          size_t byte_index = (y * DISPLAY_WIDTH + x) / 8;
+          size_t bit_index = 7 - (x % 8);
+          bool is_white = ((x / 20) % 2) == ((y / 20) % 2);
+          if (is_white) {
+            framebuffer[byte_index] |= (1 << bit_index); // Set bit to 1 for white
+          } else {
+            framebuffer[byte_index] &= ~(1 << bit_index); // Clear bit to 0 for black
+          }
+        }
+        // Yield and reset watchdog periodically
+        const size_t YIELD_INTERVAL = 16;
+        if (y % YIELD_INTERVAL == 0) {
+          if (wdt_err == ESP_OK) {
+            esp_task_wdt_reset();
+          }
+          vTaskDelay(1 / portTICK_PERIOD_MS);
+          // partial refresh to show progress
+          int32_t y_start = static_cast<int32_t>((y >= YIELD_INTERVAL - 1) ? (y - (YIELD_INTERVAL - 1)) : 0);
+          int32_t y_end = static_cast<int32_t>(y);
+          // get the partial framebuffer for this area
+          uint8_t* partial_framebuffer = &framebuffer[y_start * (DISPLAY_WIDTH / 8)];
+          esp_err_t err = display_handler->partial_refresh(partial_framebuffer, RefreshArea { 0, y_start, DISPLAY_WIDTH - 1, y_end });
+          if (err != ESP_OK) {
+            ESP_LOGE(TAG, "Partial refresh failed at y=%d: %s", y, esp_err_to_name(err));
+          }
+          // wait for 4 seconds to prevent spamming the display
+          // vTaskDelay(2000 / portTICK_PERIOD_MS);
+        }
+      }
+      // Perform full write to display
+      // esp_err_t err = display_handler->full_write(framebuffer);
+      // if (err != ESP_OK) {
+      //   ESP_LOGE(TAG, "Checkerboard full write failed: %s", esp_err_to_name(err));
+      // } else {
+      //   ESP_LOGI(TAG, "Checkerboard pattern displayed successfully.");
+      // }
+      delete[] framebuffer;
+
+      // Remove task from watchdog before deletion
+      if (wdt_err == ESP_OK) {
+        esp_task_wdt_delete(NULL);
+      }
+    } else {
+      ESP_LOGE(TAG, "Invalid parameters for checkerboard task");
+    }
+    vTaskDelete(NULL);
+    };
+  CheckerboardTaskParams* checker_params = new CheckerboardTaskParams();
+  checker_params->display_handler = display_handler;
+  BaseType_t res = xTaskCreate(
+    checkerboard_task_fn,
+    "checkerboard_task",
+    8192,
+    static_cast<void*>(checker_params),
+    tskIDLE_PRIORITY + 1,
+    NULL
+  );
+
+  if (res != pdPASS) {
+    ESP_LOGE(TAG, "Failed to create checkerboard task");
+    delete checker_params;
+  }
+}
+
+void LVGL_Checkerboard(
+  LVGLHandler* lvgl_handler
+) {
+  struct CheckerboardTaskParams {
+    LVGLHandler* lvgl_handler;
+  };
+  auto checkerboard_task_fn = [](void* pvParameters) {
+    CheckerboardTaskParams* params = static_cast<CheckerboardTaskParams*>(pvParameters);
+    if (params == nullptr || params->lvgl_handler == nullptr) {
+      ESP_LOGE(TAG, "Invalid parameters for LVGL checkerboard task");
+      delete params;
+      vTaskDelete(NULL);
+      return;
+    }
+    auto* handler = static_cast<LVGLHandler*>(params->lvgl_handler);
+
+    // Add safety checks
+    if (!handler) {
+      ESP_LOGE("LVGL", "Handler is null!");
+      delete params;
+      vTaskDelete(NULL);
+      return;
+    }
+
+    ESP_LOGI("HEAP", "Free: %d", esp_get_free_heap_size());
+
+    // Wait for LVGL system to fully initialize
+    vTaskDelay(pdMS_TO_TICKS(200));
+
+    // Acquire LVGL lock with proper timeout
+    if (!lvgl_port_lock(pdMS_TO_TICKS(5000))) {
+      ESP_LOGE(TAG, "Failed to acquire LVGL lock for checkerboard");
+      delete params;
+      vTaskDelete(NULL);
+      return;
+    }
+
+    // Verify LVGL is properly initialized
+    if (lv_display_get_default() == nullptr) {
+      ESP_LOGE(TAG, "LVGL default display not available");
+      lvgl_port_unlock();
+      delete params;
+      vTaskDelete(NULL);
+      return;
+    }
+
+    // Create LVGL objects for checkerboard
+    lv_obj_t* scr = lv_scr_act();
+    if (scr == nullptr) {
+      ESP_LOGE(TAG, "Failed to get active LVGL screen");
+      lvgl_port_unlock();
+      delete params;
+      vTaskDelete(NULL);
+      return;
+    }
+    lv_obj_t* checkerboard = lv_obj_create(scr);
+    if (checkerboard == nullptr) {
+      ESP_LOGE(TAG, "Failed to create LVGL checkerboard object");
+      lvgl_port_unlock();
+      delete params;
+      vTaskDelete(NULL);
+      return;
+    }
+    lv_obj_set_size(checkerboard, DISPLAY_WIDTH, DISPLAY_HEIGHT);
+    // remove border and padding
+    lv_obj_set_style_pad_all(checkerboard, 0, 0);
+    lv_obj_set_style_border_width(checkerboard, 0, 0);
+    const int CELL_SIZE = 40;
+    lvgl_port_unlock();
+    // Create checkerboard pattern using LVGL
+    for (int y = 0; y < DISPLAY_HEIGHT; y += CELL_SIZE) {
+      lvgl_port_lock(pdMS_TO_TICKS(1000));
+      for (int x = 0; x < DISPLAY_WIDTH; x += CELL_SIZE) {
+        lv_color_t color = (((x / CELL_SIZE) % 2) == ((y / CELL_SIZE) % 2)) ? lv_color_hex(0xFFFFFF) : lv_color_hex(0x000000);
+        lv_obj_t* cell = lv_obj_create(checkerboard);
+        if (cell == nullptr) {
+          ESP_LOGE(TAG, "Failed to create LVGL checkerboard cell");
+          lvgl_port_unlock();
+          continue;
+        }
+        lv_obj_set_size(cell, CELL_SIZE, CELL_SIZE);
+        lv_obj_set_style_bg_color(cell, color, 0);
+        lv_obj_set_pos(cell, x, y);
+        // remove border and padding
+        lv_obj_set_style_pad_all(cell, 0, 0);
+        lv_obj_set_style_border_width(cell, 0, 0);
+        lv_obj_t* label = lv_label_create(cell);
+        if (label != nullptr) {
+          lv_label_set_text_fmt(label, "(%d,%d)", x, y);
+          lv_obj_center(label);
+        }
+      }
+      lvgl_port_unlock();
+      // Yield to allow LVGL to process rendering
+      vTaskDelay(5000 / portTICK_PERIOD_MS);
+    }
+
+
+
+    ESP_LOGI(TAG, "LVGL Checkerboard pattern displayed successfully.");
+    delete params;
+    vTaskDelete(NULL);
+    };
+  CheckerboardTaskParams* checker_params = new CheckerboardTaskParams();
+  checker_params->lvgl_handler = lvgl_handler;
+  BaseType_t res = xTaskCreate(
+    checkerboard_task_fn,
+    "lvgl_checkerboard_task",
+    8192,
+    static_cast<void*>(checker_params),
+    tskIDLE_PRIORITY + 1,
+    NULL
+  );
+  if (res != pdPASS) {
+    ESP_LOGE(TAG, "Failed to create LVGL checkerboard task");
+    delete checker_params;
+  }
+}
+
+
 void app_main(void) {
   display_chip_info();
 
@@ -54,20 +272,14 @@ void app_main(void) {
   ESP_LOGI(TAG, "Queues initialized.\n");
 
   //
-  KVStorageHandler* kv_storage_handler = new NVSStorageHandler(
-    DEFAULT_STORAGE_NAMESPACE
-  );
+  // KVStorageHandler* kv_storage_handler = new NVSStorageHandler(
+  //   DEFAULT_STORAGE_NAMESPACE
+  // );
 
-  auto fs_handler = std::make_shared<LittleFSHandler>();
-  esp_err_t fs_err = fs_handler->init("/littlefs");
-  if (fs_err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize LittleFS: %s", esp_err_to_name(fs_err));
-    vTaskDelay(5000 / portTICK_PERIOD_MS);
-    return esp_restart();
-  }
-
-  auto wifi_handler = std::make_unique<WifiHandler>(fs_handler);
-  NetworkHandler* network_handler = new NetworkHandler(std::move(wifi_handler));
+  // auto wifi_handler = std::make_unique<WifiHandler>(
+  //   std::unique_ptr<KVStorageHandler>(new NVSStorageHandler(WIFI_CREDENTIALS_STORAGE_NAMESPACE))
+  // );
+  // NetworkHandler* network_handler = new NetworkHandler(std::move(wifi_handler));
   EInkDisplayHandler* display_handler = new EInkDisplayHandler();
   // Initialize display and touch
   // display_handler->init_devices(system_event_group);
@@ -84,8 +296,8 @@ void app_main(void) {
   }
 
   //
-  kv_storage_handler->init(system_event_group);
-  network_handler->init(system_event_group);
+  // kv_storage_handler->init(system_event_group);
+  // network_handler->init(system_event_group);
 
   //
   ESP_LOGI(TAG, "Waiting for system to be ready...\n");
@@ -100,19 +312,40 @@ void app_main(void) {
   );
   ESP_LOGI(TAG, "System is ready. Starting main application...\n");
 
-  // DiscordAppDescriptor::instance();
-  UIHandler ui_handler;
-  err = ui_handler.init();
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize UI handler: %s", esp_err_to_name(err));
-    vTaskDelay(5000 / portTICK_PERIOD_MS);
-    return esp_restart();
-  }
-  ESP_LOGI(TAG, "UI handler initialized.\n");
-
   // Allow LVGL system to stabilize before creating objects
   vTaskDelay(pdMS_TO_TICKS(100));
 
+  // Show checkerboard pattern on display for testing
+  // EInk_Checkerboard(display_handler);
+  LVGL_Checkerboard(&lvgl_handler);
+
+  // Register apps with AppRegistry by creating their descriptors
+  // Each descriptor will create and register the app instance
+  // DemoAppDescriptor* demo_descriptor = new DemoAppDescriptor();
+  // ShutdownAppDescriptor* shutdown_descriptor = new ShutdownAppDescriptor();
+  // DiscordAppDescriptor::instance(); // Use singleton pattern for Discord app
+  // MtrAppDescriptor* mtr_descriptor = new MtrAppDescriptor();
+
+  // Pass network handler to MtrApp so it can fetch arrival data
+  // MtrApp* mtr_app = dynamic_cast<MtrApp*>(mtr_descriptor->get_app_instance());
+  // if (mtr_app) {
+  //   mtr_app->set_network_handler(network_handler);
+  // }
+
+  // ESP_LOGI(TAG, "Apps registered with AppRegistry\n");
+
+  // Initialize UI Handler (will render app icons from registry)
+  // UIHandler ui_handler;
+  // if (ui_handler.init() != ESP_OK) {
+  //   ESP_LOGE(TAG, "Failed to initialize UI handler");
+  //   vTaskDelay(5000 / portTICK_PERIOD_MS);
+  //   return esp_restart();
+  // }
+  // ESP_LOGI(TAG, "UI handler initialized successfully\n");
+  // ESP_LOGI(TAG, "Main screen displayed with app icons. Tap an icon to launch an app.\n");
+
+
+
   // wait for shutdown signal
   ESP_LOGI(TAG, "Waiting for shutdown signal...\n");
   EventBits_t bits = xEventGroupWaitBits(

main/network/wifi_handler.cpp

@@ -8,27 +8,16 @@
 #include "common/semaphore_guard.h"
 #include "cJSON.h"
 
-#define TAG "WifiHandler"
-#define WIFI_CRED_FILE_PATH "wifi_credentials.json"
-
-/*
- * WiFi Credentials JSON Structure:
- * {
- *   "current_ssid": "MyWiFi",
- *   "credentials": {
- *     "MyWiFi": {
- *       "password": "mypassword123"
- *     },
- *     "OtherNetwork": {
- *       "password": "otherpass456"
- *     }
- *   }
- * }
- */
+static const char* TAG = "WifiHandler";
+static const char* WIFI_SSID_KEY = "ssid";
+static const char* WIFI_PASSWORD_STORE_KEY = "psw";
 
 WifiHandler::WifiHandler(
-  std::shared_ptr<LittleFSHandler> fs_handler_
-) : fs_handler_(std::move(fs_handler_)) {
+  // this handler is used to store/retrieve WiFi credentials
+  // should have a unique namespace for WiFi credentials
+  // it will be owned by WifiHandler and deleted in its destructor
+  std::unique_ptr<KVStorageHandler> kvs
+) : kvs(std::move(kvs)) {
   this->s_wifi_event_group = xEventGroupCreate();
   if (!this->s_wifi_event_group) {
     ESP_LOGE(TAG, "Failed to create WiFi event group");
@@ -45,13 +34,10 @@ WifiHandler::WifiHandler(
   if (!this->credential_mutex) {
     ESP_LOGE(TAG, "Failed to create credential mutex");
   }
-  if (this->fs_handler_ == nullptr) {
-    ESP_LOGW(TAG, "FSHandler is null, WiFi credentials will not be stored");
+  if (this->kvs == nullptr) {
+    ESP_LOGW(TAG, "KVStorageHandler is null, WiFi credentials will not be stored");
   } else {
-    esp_err_t err = this->fs_handler_->init("/littlefs");
-    if (err != ESP_OK) {
-      ESP_LOGE(TAG, "Failed to initialize FSHandler: %s", esp_err_to_name(err));
-    }
+    this->kvs->init(nullptr);
   }
 }
 
@@ -69,8 +55,8 @@ WifiHandler::~WifiHandler() {
     esp_event_handler_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, &WifiHandler::wifi_event_handler);
     esp_event_handler_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, &WifiHandler::wifi_event_handler);
     this->initialized = false;
-    //
-    this->fs_handler_ = nullptr;
+    // unique_ptr will automatically delete the object
+    this->kvs = nullptr;
   }
 }
 
@@ -174,7 +160,6 @@ esp_err_t WifiHandler::connect(const std::string& ssid, const std::string& passw
     this->current_ssid.clear();
   }
   this->current_ssid = ssid;
-  this->current_password = password;
 
   //
   wifi_config_t wifi_config = {};
@@ -197,8 +182,8 @@ esp_err_t WifiHandler::connect(const std::string& ssid, const std::string& passw
     return err;
   }
 
-  // Note: Credentials will be stored in the event handler after successful connection
-  // to avoid storing credentials for failed connection attempts
+  // store credentials after successful connection attempt
+  this->store_wifi_credentials(this->current_ssid, password);
 
   return ESP_OK;
 }
@@ -320,10 +305,6 @@ void WifiHandler::wifi_event_handler(void* arg, esp_event_base_t event_base, int
         self->s_wifi_event_group,
         WIFI_CONNECTED_BIT
       );
-      // Store credentials only after successful connection
-      if (!self->current_ssid.empty() && !self->current_password.empty()) {
-        self->store_wifi_credentials(self->current_ssid, self->current_password);
-      }
       break;
     }
     default:
@@ -337,8 +318,8 @@ void WifiHandler::wifi_event_handler(void* arg, esp_event_base_t event_base, int
 //
 
 void WifiHandler::store_wifi_credentials(const std::string& ssid, const std::string& password) {
-  if (!fs_handler_) {
-    ESP_LOGW(TAG, "FSHandler not set, cannot store WiFi credentials");
+  if (!kvs) {
+    ESP_LOGW(TAG, "KVStorageHandler not set, cannot store WiFi credentials");
     return;
   }
   SemaphoreGuard guard(this->credential_mutex);
@@ -347,187 +328,95 @@ void WifiHandler::store_wifi_credentials(const std::string& ssid, const std::str
     ESP_LOGE(TAG, "Failed to take credential mutex");
     return;
   }
-
+  // store the password according to the JSON structure
+  std::string password_key_store = kvs->get(WIFI_PASSWORD_STORE_KEY);
   cJSON* json = nullptr;
-
-  // Try to read existing credentials file
-  if (fs_handler_->file_exists(WIFI_CRED_FILE_PATH)) {
-    // Read existing file
-    size_t file_size = 0;
-    esp_err_t err = fs_handler_->get_file_size(WIFI_CRED_FILE_PATH, file_size);
-    if (err == ESP_OK && file_size > 0) {
-      std::vector<uint8_t> file_data(file_size + 1); // +1 for null terminator
-      size_t bytes_read = 0;
-      err = fs_handler_->read_file(WIFI_CRED_FILE_PATH, file_size, file_data.data(), bytes_read);
-      if (err == ESP_OK) {
-        file_data[bytes_read] = '\0'; // Null terminate
-        json = cJSON_Parse(reinterpret_cast<const char*>(file_data.data()));
-        if (json == nullptr) {
-          ESP_LOGE(TAG, "Failed to parse existing WiFi credentials JSON, creating new");
-        }
-      }
-    }
-  }
-
-  // Create new JSON if parsing failed or file doesn't exist
+  if (password_key_store.empty()) {
+    // create new JSON object
+    json = cJSON_CreateObject();
+  } else {
+    // parse existing JSON
+    json = cJSON_Parse(password_key_store.c_str());
     if (json == nullptr) {
+      ESP_LOGE(TAG, "Failed to parse existing WiFi password JSON, creating new");
       json = cJSON_CreateObject();
     }
-
-  // Set current SSID
-  cJSON* current_ssid_item = cJSON_GetObjectItem(json, "current_ssid");
-  if (current_ssid_item != nullptr) {
-    cJSON_SetValuestring(current_ssid_item, ssid.c_str());
-  } else {
-    cJSON_AddStringToObject(json, "current_ssid", ssid.c_str());
   }
-
-  // Get or create credentials object
   cJSON* credentials = cJSON_GetObjectItem(json, "credentials");
   if (credentials == nullptr || !cJSON_IsObject(credentials)) {
+    // create credentials object if it doesn't exist
     credentials = cJSON_CreateObject();
     cJSON_AddItemToObject(json, "credentials", credentials);
   }
-
-  // Limit stored credentials to prevent excessive file size (keep max 10 SSIDs)
-  int credential_count = cJSON_GetArraySize(credentials);
-  if (credential_count >= 10) {
-    ESP_LOGW(TAG, "Too many stored credentials (%d), keeping only current SSID", credential_count);
-    // Keep only the current SSID's credentials
-    cJSON* new_credentials = cJSON_CreateObject();
-    cJSON_ReplaceItemInObject(json, "credentials", new_credentials);
-    credentials = new_credentials;
-  }
-
-  // Remove existing entry for this SSID to update it
-  cJSON_DeleteItemFromObject(credentials, ssid.c_str());
-
-  // Create SSID object with password
+  // create SSID object
   cJSON* ssid_item = cJSON_CreateObject();
+  // add password field
   cJSON_AddStringToObject(ssid_item, "password", password.c_str());
+  // add SSID object to credentials
   cJSON_AddItemToObject(credentials, ssid.c_str(), ssid_item);
-
-  // Serialize and write to file
-  char* json_str = cJSON_PrintUnformatted(json);
-  if (json_str) {
-    size_t bytes_written = 0;
-    esp_err_t err = fs_handler_->write_file(
-      WIFI_CRED_FILE_PATH,
-      reinterpret_cast<const uint8_t*>(json_str),
-      strlen(json_str),
-      bytes_written
-    );
-    if (err != ESP_OK) {
-      ESP_LOGE(TAG, "Failed to write WiFi credentials to file: %s", esp_err_to_name(err));
-    } else {
-      ESP_LOGI(TAG, "Stored WiFi credentials for SSID: %s", ssid.c_str());
-    }
-    cJSON_free(json_str);
-  } else {
-    ESP_LOGE(TAG, "Failed to serialize WiFi credentials JSON");
+  // store updated JSON string
+  char* updated_json_str = cJSON_PrintUnformatted(json);
+  if (updated_json_str) {
+    kvs->put(WIFI_PASSWORD_STORE_KEY, std::string(updated_json_str));
+    cJSON_free(updated_json_str);
   }
   cJSON_Delete(json);
 }
 
 void WifiHandler::get_wifi_credentials(std::string& out_ssid, std::string& out_password) {
-  if (!fs_handler_) {
-    ESP_LOGW(TAG, "FSHandler not set, cannot get WiFi credentials");
-    out_ssid = "";
-    out_password = "";
+  if (!kvs) {
+    ESP_LOGW(TAG, "KVStorageHandler not set, cannot get WiFi credentials");
     return;
   }
-
   SemaphoreGuard guard(this->credential_mutex);
   // wait up to 5 seconds to take the mutex
   if (!guard.take(5000 / portTICK_PERIOD_MS)) {
     ESP_LOGE(TAG, "Failed to take credential mutex");
+    return;
+  }
+  out_ssid = kvs->get(WIFI_SSID_KEY);
+  if (out_ssid.empty()) {
     out_ssid = "";
     out_password = "";
     return;
   }
-
-  // Check if credentials file exists
-  if (!fs_handler_->file_exists(WIFI_CRED_FILE_PATH)) {
-    ESP_LOGD(TAG, "WiFi credentials file does not exist");
-    out_ssid = "";
+  // password is from KV storage, may be nullptr
+  std::string password_key_store = kvs->get(WIFI_PASSWORD_STORE_KEY);
+  if (password_key_store.empty()) {
     out_password = "";
     return;
   }
-
-  // Read credentials file
-  size_t file_size = 0;
-  esp_err_t err = fs_handler_->get_file_size(WIFI_CRED_FILE_PATH, file_size);
-  if (err != ESP_OK || file_size == 0) {
-    ESP_LOGE(TAG, "Failed to get WiFi credentials file size");
-    out_ssid = "";
-    out_password = "";
-    return;
-  }
-
-  std::vector<uint8_t> file_data(file_size + 1); // +1 for null terminator
-  size_t bytes_read = 0;
-  err = fs_handler_->read_file(WIFI_CRED_FILE_PATH, file_size, file_data.data(), bytes_read);
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to read WiFi credentials file: %s", esp_err_to_name(err));
-    out_ssid = "";
-    out_password = "";
-    return;
-  }
-  file_data[bytes_read] = '\0'; // Null terminate
-
-  // Parse JSON
-  cJSON* json = cJSON_Parse(reinterpret_cast<const char*>(file_data.data()));
+  // parse from json
+  cJSON* json = cJSON_Parse(password_key_store.c_str());
   if (json == nullptr) {
-    ESP_LOGE(TAG, "Failed to parse WiFi credentials JSON");
-    out_ssid = "";
+    ESP_LOGE(TAG, "Failed to parse WiFi password JSON");
     out_password = "";
     return;
   }
-
-  // Get current SSID
-  cJSON* current_ssid_item = cJSON_GetObjectItem(json, "current_ssid");
-  if (current_ssid_item == nullptr || !cJSON_IsString(current_ssid_item)) {
-    ESP_LOGE(TAG, "WiFi credentials JSON does not contain valid 'current_ssid' field");
-    out_ssid = "";
-    out_password = "";
-    cJSON_Delete(json);
-    return;
-  }
-  out_ssid = current_ssid_item->valuestring;
-
-  // Get credentials object
   cJSON* credentials = cJSON_GetObjectItem(json, "credentials");
   if (credentials == nullptr || !cJSON_IsObject(credentials)) {
-    ESP_LOGE(TAG, "WiFi credentials JSON does not contain valid 'credentials' object");
-    out_ssid = "";
+    ESP_LOGE(TAG, "WiFi password JSON does not contain valid 'credentials' object");
     out_password = "";
     cJSON_Delete(json);
     return;
   }
-
-  // Get SSID entry
+  // get the ssid value
   cJSON* ssid_item = cJSON_GetObjectItem(credentials, out_ssid.c_str());
   if (ssid_item == nullptr || !cJSON_IsObject(ssid_item)) {
-    ESP_LOGE(TAG, "WiFi credentials JSON does not contain entry for SSID: %s", out_ssid.c_str());
-    out_ssid = "";
+    ESP_LOGE(TAG, "WiFi password JSON does not contain valid SSID field for SSID: %s", out_ssid.c_str());
     out_password = "";
     cJSON_Delete(json);
     return;
   }
-
-  // Get password
-  cJSON* password_item = cJSON_GetObjectItem(ssid_item, "password");
-  if (password_item == nullptr || !cJSON_IsString(password_item)) {
-    ESP_LOGE(TAG, "WiFi credentials JSON does not contain valid 'password' field for SSID: %s", out_ssid.c_str());
-    out_ssid = "";
+  cJSON* password = cJSON_GetObjectItem(ssid_item, "password");
+  if (password == nullptr || !cJSON_IsString(password)) {
+    ESP_LOGE(TAG, "WiFi password JSON does not contain valid 'password' field for SSID: %s", out_ssid.c_str());
     out_password = "";
     cJSON_Delete(json);
     return;
   }
-  out_password = password_item->valuestring;
-
+  out_password = password->valuestring;
   cJSON_Delete(json);
-  ESP_LOGD(TAG, "Retrieved WiFi credentials for SSID: %s", out_ssid.c_str());
 }
 
 EventBits_t WifiHandler::wait_for_connection(TickType_t ticks_to_wait) {

main/network/wifi_handler.h

@@ -1,6 +1,5 @@
 #pragma once
-#include "freertos/FreeRTOS.h"
-#include "io/fs_handler.h"
+#include "io/io.h"
 #include "esp_wifi.h"
 #include "freertos/event_groups.h"
 
@@ -14,7 +13,7 @@ public:
     // this handler is used to store/retrieve WiFi credentials
     // should have a unique namespace for WiFi credentials
     // it will be owned by WifiHandler and deleted in its destructor
-    std::shared_ptr<LittleFSHandler> fs_handler_
+    std::unique_ptr<KVStorageHandler> kvs
   );
   ~WifiHandler();
 
@@ -45,15 +44,13 @@ private:
   void get_wifi_credentials(std::string& out_ssid, std::string& out_password);
 
   bool initialized = false;
-  std::shared_ptr<LittleFSHandler> fs_handler_ = nullptr;
+  std::unique_ptr<KVStorageHandler> kvs = nullptr;
   EventGroupHandle_t s_wifi_event_group = 0;
   SemaphoreHandle_t scan_mutex = nullptr;
   SemaphoreHandle_t connection_mutex = nullptr;
   SemaphoreHandle_t credential_mutex = nullptr;
   // current connected / preferred SSID
   std::string current_ssid;
-  // current password (temporarily stored for successful connection event)
-  std::string current_password;
   // prevent auto-reconnect on expected disconnection, e.g. when user calls disconnect()
   // should be reset to false after connect()
   bool expect_disconnected = false;

main/ui/app_registry.h

@@ -0,0 +1,39 @@
+#pragma once
+#include "ui/ui_app.h"
+#include <vector>
+
+/**
+ * @brief Registry for all available apps
+ *
+ * This singleton class maintains a list of all registered
+ * AppDescriptor instances, allowing the UIHandler or other
+ * components to query available apps.
+ */
+class AppRegistry {
+public:
+  static AppRegistry& instance() {
+    static AppRegistry registry;
+    return registry;
+  }
+
+  AppRegistry(const AppRegistry&) = delete;
+  void operator=(const AppRegistry&) = delete;
+  AppRegistry(AppRegistry&&) = delete;
+  void operator=(AppRegistry&&) = delete;
+
+
+  // Register a new app descriptor
+  // The registry takes ownership of the descriptor pointer.
+  void register_app(AppDescriptor* app_descriptor) {
+    _app_descriptors.push_back(app_descriptor);
+  }
+
+  const std::vector<AppDescriptor*>& get_app_descriptors() const {
+    return _app_descriptors;
+  }
+
+private:
+  AppRegistry() = default;
+  ~AppRegistry() = default;
+  std::vector<AppDescriptor*> _app_descriptors = {};
+};

main/ui/apps/discord_app.cpp

@@ -0,0 +1,652 @@
+#include "discord_app.h"
+#include "esp_log.h"
+#include "network/network.h"
+#include <sstream>
+
+static const char* TAG = "DiscordApp";
+
+// ============================================================================
+// DiscordApp Implementation
+// ============================================================================
+
+DiscordApp::DiscordApp()
+  : page_stack_(nullptr)
+  , status_icon_label_(nullptr)
+  , status_text_label_(nullptr)
+  , mute_button_(nullptr)
+  , error_notification_(nullptr)
+  , ip_textarea_(nullptr)
+  , port_textarea_(nullptr)
+  , test_result_label_(nullptr)
+  , remote_port_(0)
+  , settings_configured_(false)
+  , current_state_(VoiceState::UNKNOWN)
+  , state_mutex_(nullptr)
+  , poll_task_handle_(nullptr)
+  , stop_polling_(false)
+  , consecutive_failures_(0)
+  , storage_(nullptr) {
+
+  // Create mutex for thread-safe state access
+  state_mutex_ = xSemaphoreCreateMutex();
+
+  // Initialize storage
+  storage_ = new NVSStorageHandler(NVS_NAMESPACE);
+}
+
+DiscordApp::~DiscordApp() {
+  stop_polling_task();
+
+  if (state_mutex_) {
+    vSemaphoreDelete(state_mutex_);
+  }
+
+  if (storage_) {
+    delete storage_;
+  }
+}
+
+esp_err_t DiscordApp::init(lv_obj_t* container) {
+  ESP_LOGI(TAG, "Initializing Discord app");
+
+  _container = container;
+
+  // Initialize storage
+  storage_->init(nullptr);
+
+  // Load saved settings
+  load_settings();
+
+  // Initialize UDP client
+  udp_client_.init();
+
+  // Configure UDP if settings are available
+  if (settings_configured_) {
+    udp_client_.configure(remote_ip_, remote_port_);
+  }
+
+  // Create page stack
+  page_stack_ = new PageStack(container);
+
+  // Build main page
+  page_stack_->push([this](lv_obj_t* page) {
+    build_main_page(page);
+    });
+
+  // Start polling task
+  start_polling_task();
+
+  return ESP_OK;
+}
+
+esp_err_t DiscordApp::deinit() {
+  ESP_LOGI(TAG, "Deinitializing Discord app");
+
+  // Stop polling
+  stop_polling_task();
+
+  // Clean up page stack
+  if (page_stack_) {
+    delete page_stack_;
+    page_stack_ = nullptr;
+  }
+
+  // Close UDP client
+  udp_client_.close();
+
+  // Reset widget pointers
+  status_icon_label_ = nullptr;
+  status_text_label_ = nullptr;
+  mute_button_ = nullptr;
+  error_notification_ = nullptr;
+  ip_textarea_ = nullptr;
+  port_textarea_ = nullptr;
+  test_result_label_ = nullptr;
+
+  return ESP_OK;
+}
+
+void DiscordApp::handle_event(uint32_t event_type, void* event_data) {
+  // Handle system events if needed
+}
+
+bool DiscordApp::on_back_button_pressed() {
+  // If on settings page, go back to main page
+  if (page_stack_ && page_stack_->depth() > 1) {
+    page_stack_->pop();
+    return true;
+  }
+
+  // Let system handle back (return to app icons)
+  return false;
+}
+
+// ============================================================================
+// Main Page UI
+// ============================================================================
+
+void DiscordApp::build_main_page(lv_obj_t* page) {
+  // Set up main page with flex column layout
+  lv_obj_set_flex_flow(page, LV_FLEX_FLOW_COLUMN);
+  lv_obj_set_flex_align(page, LV_FLEX_ALIGN_SPACE_BETWEEN, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+  lv_obj_set_style_pad_all(page, 10, 0);
+
+  // === Top Section: Error Notification ===
+  error_notification_ = lv_obj_create(page);
+  lv_obj_set_width(error_notification_, LV_PCT(90));
+  lv_obj_set_height(error_notification_, LV_SIZE_CONTENT);
+  lv_obj_set_style_bg_color(error_notification_, lv_color_hex(0xFF0000), 0);
+  lv_obj_set_style_bg_opa(error_notification_, LV_OPA_70, 0);
+  lv_obj_set_style_pad_all(error_notification_, 10, 0);
+  lv_obj_set_style_radius(error_notification_, 8, 0);
+  lv_obj_add_flag(error_notification_, LV_OBJ_FLAG_HIDDEN);
+  lv_obj_set_flex_flow(error_notification_, LV_FLEX_FLOW_ROW);
+  lv_obj_set_flex_align(error_notification_, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+
+  lv_obj_t* error_label = lv_label_create(error_notification_);
+  lv_label_set_text(error_label, LV_SYMBOL_WARNING " Connection Lost");
+  lv_obj_set_style_text_color(error_label, lv_color_white(), 0);
+
+  // === Center Section: Main Content ===
+  lv_obj_t* center_container = lv_obj_create(page);
+  lv_obj_set_size(center_container, LV_PCT(100), LV_SIZE_CONTENT);
+  lv_obj_set_style_bg_opa(center_container, LV_OPA_TRANSP, 0);
+  lv_obj_set_style_border_width(center_container, 0, 0);
+  lv_obj_set_style_pad_all(center_container, 0, 0);
+  lv_obj_set_flex_flow(center_container, LV_FLEX_FLOW_COLUMN);
+  lv_obj_set_flex_align(center_container, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+  lv_obj_set_style_pad_row(center_container, 15, 0);
+  lv_obj_set_flex_grow(center_container, 1);
+
+  // Status icon (large, centered)
+  status_icon_label_ = lv_label_create(center_container);
+  lv_label_set_text(status_icon_label_, LV_SYMBOL_MUTE);
+
+  // Status text
+  status_text_label_ = lv_label_create(center_container);
+  lv_label_set_text(status_text_label_, "Unknown Status");
+
+  // Mute button
+  mute_button_ = lv_btn_create(center_container);
+  lv_obj_set_size(mute_button_, 200, 60);
+  lv_obj_add_event_cb(mute_button_, on_mute_button_clicked, LV_EVENT_CLICKED, this);
+
+  lv_obj_t* mute_label = lv_label_create(mute_button_);
+  lv_label_set_text(mute_label, "MUTE");
+  lv_obj_center(mute_label);
+
+  // === Bottom Section: Settings and Config Prompt ===
+  lv_obj_t* bottom_container = lv_obj_create(page);
+  lv_obj_set_size(bottom_container, LV_PCT(100), LV_SIZE_CONTENT);
+  lv_obj_set_style_bg_opa(bottom_container, LV_OPA_TRANSP, 0);
+  lv_obj_set_style_border_width(bottom_container, 0, 0);
+  lv_obj_set_style_pad_all(bottom_container, 0, 0);
+  lv_obj_set_flex_flow(bottom_container, LV_FLEX_FLOW_ROW);
+  lv_obj_set_flex_align(bottom_container, LV_FLEX_ALIGN_SPACE_BETWEEN, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+
+  // Config prompt (left side)
+  if (!settings_configured_) {
+    lv_obj_t* config_prompt = lv_label_create(bottom_container);
+    lv_label_set_text(config_prompt, "Tap " LV_SYMBOL_SETTINGS " to configure");
+    lv_obj_set_style_text_color(config_prompt, lv_color_hex(0x888888), 0);
+  } else {
+    // Empty spacer if configured
+    lv_obj_t* spacer = lv_obj_create(bottom_container);
+    lv_obj_set_size(spacer, 0, 0);
+    lv_obj_set_style_bg_opa(spacer, LV_OPA_TRANSP, 0);
+    lv_obj_set_style_border_width(spacer, 0, 0);
+  }
+
+  // Settings button (right side)
+  lv_obj_t* settings_btn = lv_btn_create(bottom_container);
+  lv_obj_set_size(settings_btn, 60, 60);
+  lv_obj_add_event_cb(settings_btn, on_settings_button_clicked, LV_EVENT_CLICKED, this);
+
+  lv_obj_t* settings_icon = lv_label_create(settings_btn);
+  lv_label_set_text(settings_icon, LV_SYMBOL_SETTINGS);
+  lv_obj_center(settings_icon);
+
+  // Update display with current state
+  update_status_display();
+}
+
+// ============================================================================
+// Settings Page UI
+// ============================================================================
+
+void DiscordApp::build_settings_page(lv_obj_t* page) {
+  // Title
+  lv_obj_t* title = lv_label_create(page);
+  lv_label_set_text(title, "Discord Bridge Settings");
+  // Using default font
+  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 20);
+
+  // IP address label
+  lv_obj_t* ip_label = lv_label_create(page);
+  lv_label_set_text(ip_label, "Bridge IP Address:");
+  lv_obj_align(ip_label, LV_ALIGN_TOP_LEFT, 20, 70);
+
+  // IP address textarea
+  ip_textarea_ = lv_textarea_create(page);
+  lv_obj_set_size(ip_textarea_, 300, 50);
+  lv_obj_align(ip_textarea_, LV_ALIGN_TOP_LEFT, 20, 100);
+  lv_textarea_set_one_line(ip_textarea_, true);
+  lv_textarea_set_placeholder_text(ip_textarea_, "e.g., 192.168.1.100");
+
+  if (!remote_ip_.empty()) {
+    lv_textarea_set_text(ip_textarea_, remote_ip_.c_str());
+  }
+
+  // Port label
+  lv_obj_t* port_label = lv_label_create(page);
+  lv_label_set_text(port_label, "Bridge Port:");
+  lv_obj_align(port_label, LV_ALIGN_TOP_LEFT, 20, 170);
+
+  // Port textarea
+  port_textarea_ = lv_textarea_create(page);
+  lv_obj_set_size(port_textarea_, 150, 50);
+  lv_obj_align(port_textarea_, LV_ALIGN_TOP_LEFT, 20, 200);
+  lv_textarea_set_one_line(port_textarea_, true);
+  lv_textarea_set_placeholder_text(port_textarea_, "e.g., 4211");
+  lv_textarea_set_accepted_chars(port_textarea_, "0123456789");
+  lv_textarea_set_max_length(port_textarea_, 5);
+
+  if (remote_port_ > 0) {
+    char port_str[8];
+    snprintf(port_str, sizeof(port_str), "%u", remote_port_);
+    lv_textarea_set_text(port_textarea_, port_str);
+  }
+
+  // Test connection button
+  lv_obj_t* test_btn = lv_btn_create(page);
+  lv_obj_set_size(test_btn, 200, 50);
+  lv_obj_align(test_btn, LV_ALIGN_TOP_MID, 0, 270);
+  lv_obj_add_event_cb(test_btn, on_test_connection_clicked, LV_EVENT_CLICKED, this);
+
+  lv_obj_t* test_label = lv_label_create(test_btn);
+  lv_label_set_text(test_label, "Test Connection");
+  lv_obj_center(test_label);
+
+  // Test result label
+  test_result_label_ = lv_label_create(page);
+  lv_label_set_text(test_result_label_, "");
+  lv_obj_align(test_result_label_, LV_ALIGN_TOP_MID, 0, 330);
+
+  // Save button
+  lv_obj_t* save_btn = lv_btn_create(page);
+  lv_obj_set_size(save_btn, 150, 50);
+  lv_obj_align(save_btn, LV_ALIGN_BOTTOM_MID, 0, -20);
+  lv_obj_add_event_cb(save_btn, on_save_settings_clicked, LV_EVENT_CLICKED, this);
+  lv_obj_set_style_bg_color(save_btn, lv_color_hex(0x00AA00), 0);
+
+  lv_obj_t* save_label = lv_label_create(save_btn);
+  lv_label_set_text(save_label, LV_SYMBOL_SAVE " Save");
+  lv_obj_set_style_text_color(save_label, lv_color_white(), 0);
+  lv_obj_center(save_label);
+}
+
+void DiscordApp::show_settings_page() {
+  page_stack_->push([this](lv_obj_t* page) {
+    build_settings_page(page);
+    });
+}
+
+// ============================================================================
+// Event Callbacks
+// ============================================================================
+
+void DiscordApp::on_mute_button_clicked(lv_event_t* e) {
+  DiscordApp* app = static_cast<DiscordApp*>(lv_event_get_user_data(e));
+  if (app) {
+    app->send_mute_command();
+  }
+}
+
+void DiscordApp::on_settings_button_clicked(lv_event_t* e) {
+  DiscordApp* app = static_cast<DiscordApp*>(lv_event_get_user_data(e));
+  if (app) {
+    app->show_settings_page();
+  }
+}
+
+void DiscordApp::on_save_settings_clicked(lv_event_t* e) {
+  DiscordApp* app = static_cast<DiscordApp*>(lv_event_get_user_data(e));
+  if (app) {
+    app->save_settings();
+
+    // Go back to main page
+    if (app->page_stack_->depth() > 1) {
+      app->page_stack_->pop();
+    }
+  }
+}
+
+void DiscordApp::on_test_connection_clicked(lv_event_t* e) {
+  DiscordApp* app = static_cast<DiscordApp*>(lv_event_get_user_data(e));
+  if (!app || !app->test_result_label_) return;
+
+  // Get values from textareas
+  const char* ip = lv_textarea_get_text(app->ip_textarea_);
+  const char* port_str = lv_textarea_get_text(app->port_textarea_);
+
+  if (strlen(ip) == 0 || strlen(port_str) == 0) {
+    lv_label_set_text(app->test_result_label_, LV_SYMBOL_CLOSE " Please fill all fields");
+    lv_obj_set_style_text_color(app->test_result_label_, lv_color_hex(0xFF0000), 0);
+    return;
+  }
+
+  uint16_t port = atoi(port_str);
+  if (port == 0) {
+    lv_label_set_text(app->test_result_label_, LV_SYMBOL_CLOSE " Invalid port");
+    lv_obj_set_style_text_color(app->test_result_label_, lv_color_hex(0xFF0000), 0);
+    return;
+  }
+
+  // Configure UDP temporarily
+  UDPClient test_client;
+  test_client.init();
+  esp_err_t err = test_client.configure(ip, port);
+
+  if (err != ESP_OK) {
+    lv_label_set_text(app->test_result_label_, LV_SYMBOL_CLOSE " Invalid IP address");
+    lv_obj_set_style_text_color(app->test_result_label_, lv_color_hex(0xFF0000), 0);
+    return;
+  }
+
+  lv_label_set_text(app->test_result_label_, "Testing...");
+  lv_obj_set_style_text_color(app->test_result_label_, lv_color_hex(0x0000FF), 0);
+
+  // Send STATUS command
+  err = test_client.send_command("STATUS");
+  if (err != ESP_OK) {
+    lv_label_set_text(app->test_result_label_, LV_SYMBOL_CLOSE " Failed to send");
+    lv_obj_set_style_text_color(app->test_result_label_, lv_color_hex(0xFF0000), 0);
+    return;
+  }
+
+  // Wait for response
+  std::string response;
+  err = test_client.receive_response(response, 3000);
+
+  if (err == ESP_OK && (response == "MUTED" || response == "UNMUTED")) {
+    lv_label_set_text(app->test_result_label_, LV_SYMBOL_OK " Connection successful!");
+    lv_obj_set_style_text_color(app->test_result_label_, lv_color_hex(0x00AA00), 0);
+  } else {
+    lv_label_set_text(app->test_result_label_, LV_SYMBOL_CLOSE " No response from bridge");
+    lv_obj_set_style_text_color(app->test_result_label_, lv_color_hex(0xFF0000), 0);
+  }
+}
+
+// ============================================================================
+// UDP Communication
+// ============================================================================
+
+void DiscordApp::send_mute_command() {
+  if (!settings_configured_) {
+    ESP_LOGW(TAG, "Cannot send command: not configured");
+    return;
+  }
+
+  esp_err_t err = udp_client_.send_command("MUTE");
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to send MUTE command");
+  }
+}
+
+bool DiscordApp::test_connection() {
+  if (!settings_configured_) {
+    return false;
+  }
+
+  esp_err_t err = udp_client_.send_command("STATUS");
+  if (err != ESP_OK) {
+    return false;
+  }
+
+  std::string response;
+  err = udp_client_.receive_response(response, RESPONSE_TIMEOUT_MS);
+
+  return (err == ESP_OK && (response == "MUTED" || response == "UNMUTED"));
+}
+
+void DiscordApp::update_status_display() {
+  if (!status_icon_label_ || !status_text_label_) {
+    return;
+  }
+
+  // Thread-safe state access
+  VoiceState state;
+  if (xSemaphoreTake(state_mutex_, pdMS_TO_TICKS(100)) == pdTRUE) {
+    state = current_state_;
+    xSemaphoreGive(state_mutex_);
+  } else {
+    return;
+  }
+
+  switch (state) {
+    case VoiceState::MUTED:
+      lv_label_set_text(status_icon_label_, LV_SYMBOL_MUTE);
+      lv_label_set_text(status_text_label_, "Muted");
+      lv_obj_set_style_text_color(status_icon_label_, lv_color_hex(0xFF0000), 0);
+      break;
+
+    case VoiceState::UNMUTED:
+      lv_label_set_text(status_icon_label_, LV_SYMBOL_VOLUME_MAX);
+      lv_label_set_text(status_text_label_, "Unmuted");
+      lv_obj_set_style_text_color(status_icon_label_, lv_color_hex(0x00AA00), 0);
+      break;
+
+    case VoiceState::ERROR:
+      lv_label_set_text(status_icon_label_, LV_SYMBOL_WARNING);
+      lv_label_set_text(status_text_label_, "Connection Error");
+      lv_obj_set_style_text_color(status_icon_label_, lv_color_hex(0xFF8800), 0);
+      break;
+
+    case VoiceState::UNKNOWN:
+    default:
+      lv_label_set_text(status_icon_label_, LV_SYMBOL_BLUETOOTH);
+      lv_label_set_text(status_text_label_, "Unknown Status");
+      lv_obj_set_style_text_color(status_icon_label_, lv_color_hex(0x888888), 0);
+      break;
+  }
+}
+
+void DiscordApp::show_error_notification(bool show) {
+  if (error_notification_) {
+    if (show) {
+      lv_obj_clear_flag(error_notification_, LV_OBJ_FLAG_HIDDEN);
+    } else {
+      lv_obj_add_flag(error_notification_, LV_OBJ_FLAG_HIDDEN);
+    }
+  }
+}
+
+// ============================================================================
+// Settings Management
+// ============================================================================
+
+void DiscordApp::load_settings() {
+  remote_ip_ = storage_->get(NVS_KEY_IP);
+  std::string port_str = storage_->get(NVS_KEY_PORT);
+
+  if (!remote_ip_.empty() && !port_str.empty()) {
+    remote_port_ = atoi(port_str.c_str());
+    settings_configured_ = (remote_port_ > 0);
+    ESP_LOGI(TAG, "Loaded settings: %s:%u", remote_ip_.c_str(), remote_port_);
+  } else {
+    settings_configured_ = false;
+    ESP_LOGI(TAG, "No settings found, user setup required");
+  }
+}
+
+void DiscordApp::save_settings() {
+  if (!ip_textarea_ || !port_textarea_) {
+    return;
+  }
+
+  const char* ip = lv_textarea_get_text(ip_textarea_);
+  const char* port_str = lv_textarea_get_text(port_textarea_);
+
+  if (strlen(ip) == 0 || strlen(port_str) == 0) {
+    ESP_LOGW(TAG, "Cannot save: empty fields");
+    return;
+  }
+
+  uint16_t port = atoi(port_str);
+  if (port == 0) {
+    ESP_LOGW(TAG, "Cannot save: invalid port");
+    return;
+  }
+
+  // Save to NVS
+  storage_->put(NVS_KEY_IP, ip);
+  storage_->put(NVS_KEY_PORT, port_str);
+
+  // Update local config
+  remote_ip_ = ip;
+  remote_port_ = port;
+  settings_configured_ = true;
+
+  // Reconfigure UDP client
+  udp_client_.configure(remote_ip_, remote_port_);
+
+  // Reset failure counter
+  consecutive_failures_ = 0;
+
+  ESP_LOGI(TAG, "Settings saved: %s:%u", remote_ip_.c_str(), remote_port_);
+}
+
+// ============================================================================
+// Polling Task
+// ============================================================================
+
+void DiscordApp::poll_task(void* param) {
+  DiscordApp* app = static_cast<DiscordApp*>(param);
+
+  ESP_LOGI(TAG, "Polling task started");
+
+  while (!app->stop_polling_) {
+    app->poll_status();
+
+    // Use longer interval if in error state
+    int interval = (app->consecutive_failures_ >= MAX_FAILURES_BEFORE_ERROR)
+      ? ERROR_POLL_INTERVAL_MS
+      : POLL_INTERVAL_MS;
+
+    vTaskDelay(pdMS_TO_TICKS(interval));
+  }
+
+  ESP_LOGI(TAG, "Polling task stopped");
+  app->poll_task_handle_ = nullptr;
+  vTaskDelete(nullptr);
+}
+
+void DiscordApp::start_polling_task() {
+  if (poll_task_handle_) {
+    ESP_LOGW(TAG, "Polling task already running");
+    return;
+  }
+
+  stop_polling_ = false;
+  xTaskCreate(poll_task, "discord_poll", 4096, this, 5, &poll_task_handle_);
+}
+
+void DiscordApp::stop_polling_task() {
+  if (!poll_task_handle_) {
+    return;
+  }
+
+  ESP_LOGI(TAG, "Stopping polling task");
+  stop_polling_ = true;
+
+  // Wait for task to finish (max 2 seconds)
+  int wait_count = 0;
+  while (poll_task_handle_ && wait_count < 20) {
+    vTaskDelay(pdMS_TO_TICKS(100));
+    wait_count++;
+  }
+
+  if (poll_task_handle_) {
+    ESP_LOGW(TAG, "Force deleting polling task");
+    vTaskDelete(poll_task_handle_);
+    poll_task_handle_ = nullptr;
+  }
+}
+
+void DiscordApp::poll_status() {
+  if (!settings_configured_) {
+    // Don't poll if not configured
+    return;
+  }
+
+  // Send STATUS command
+  esp_err_t err = udp_client_.send_command("STATUS");
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "Failed to send STATUS command");
+    consecutive_failures_++;
+
+    if (consecutive_failures_ >= MAX_FAILURES_BEFORE_ERROR) {
+      if (xSemaphoreTake(state_mutex_, pdMS_TO_TICKS(100)) == pdTRUE) {
+        current_state_ = VoiceState::ERROR;
+        xSemaphoreGive(state_mutex_);
+      }
+      show_error_notification(true);
+    }
+    return;
+  }
+
+  // Wait for response
+  std::string response;
+  err = udp_client_.receive_response(response, RESPONSE_TIMEOUT_MS);
+
+  if (err == ESP_OK) {
+    // Success - reset failure counter
+    consecutive_failures_ = 0;
+    show_error_notification(false);
+
+    // Update state
+    VoiceState new_state = VoiceState::UNKNOWN;
+    if (response == "MUTED") {
+      new_state = VoiceState::MUTED;
+    } else if (response == "UNMUTED") {
+      new_state = VoiceState::UNMUTED;
+    }
+
+    if (xSemaphoreTake(state_mutex_, pdMS_TO_TICKS(100)) == pdTRUE) {
+      current_state_ = new_state;
+      xSemaphoreGive(state_mutex_);
+    }
+
+    update_status_display();
+
+  } else {
+    // Timeout or error
+    consecutive_failures_++;
+    ESP_LOGW(TAG, "No response (failures: %d)", consecutive_failures_);
+
+    if (consecutive_failures_ >= MAX_FAILURES_BEFORE_ERROR) {
+      if (xSemaphoreTake(state_mutex_, pdMS_TO_TICKS(100)) == pdTRUE) {
+        current_state_ = VoiceState::ERROR;
+        xSemaphoreGive(state_mutex_);
+      }
+      update_status_display();
+      show_error_notification(true);
+    }
+  }
+}
+
+// ============================================================================
+// DiscordAppDescriptor Implementation
+// ============================================================================
+
+DiscordAppDescriptor::DiscordAppDescriptor()
+  : AppDescriptor("Discord", new DiscordApp()) {
+  // Auto-register on construction
+  AppRegistry::instance().register_app(this);
+}
+
+void DiscordAppDescriptor::draw_icon(lv_obj_t* parent) {
+  lv_obj_t* icon = lv_label_create(parent);
+  lv_label_set_text(icon, LV_SYMBOL_CALL);
+  lv_obj_center(icon);
+}

main/ui/apps/discord_app.h

@@ -0,0 +1,123 @@
+#pragma once
+
+#include "ui/ui_app.h"
+#include "ui/page_stack.h"
+#include "ui/app_registry.h"
+#include "network/udp_client.h"
+#include "io/nvs_handler.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/semphr.h"
+#include <string>
+
+/**
+ * @brief Discord voice control app
+ *
+ * Allows control of Discord voice settings (mute/unmute) via UDP communication
+ * with the IotDis Node.js bridge. Features:
+ * - Main page: Status icon + mute button
+ * - Settings page: IP/port configuration with connection test
+ * - Periodic status polling with automatic retry
+ * - Error notification when remote is unreachable
+ */
+class DiscordApp : public UIApp {
+public:
+    DiscordApp();
+    ~DiscordApp() override;
+
+    // UIApp interface
+    esp_err_t init(lv_obj_t* container) override;
+    esp_err_t deinit() override;
+    std::string get_name() const override { return "Discord"; }
+    void handle_event(uint32_t event_type, void* event_data = nullptr) override;
+    bool on_back_button_pressed() override;
+
+private:
+    // Voice state enum
+    enum class VoiceState {
+        UNKNOWN,
+        MUTED,
+        UNMUTED,
+        ERROR
+    };
+
+    // Page management
+    PageStack* page_stack_;
+    void build_main_page(lv_obj_t* page);
+    void build_settings_page(lv_obj_t* page);
+    void show_settings_page();
+
+    // Main page widgets
+    lv_obj_t* status_icon_label_;
+    lv_obj_t* status_text_label_;
+    lv_obj_t* mute_button_;
+    lv_obj_t* error_notification_;
+
+    // Settings page widgets
+    lv_obj_t* ip_textarea_;
+    lv_obj_t* port_textarea_;
+    lv_obj_t* test_result_label_;
+
+    // UDP client and configuration
+    UDPClient udp_client_;
+    std::string remote_ip_;
+    uint16_t remote_port_;
+    bool settings_configured_;
+
+    // Voice state
+    VoiceState current_state_;
+    SemaphoreHandle_t state_mutex_;
+
+    // Polling task
+    TaskHandle_t poll_task_handle_;
+    bool stop_polling_;
+    int consecutive_failures_;
+    static constexpr int MAX_FAILURES_BEFORE_ERROR = 3;
+    static constexpr int POLL_INTERVAL_MS = 5000;
+    static constexpr int ERROR_POLL_INTERVAL_MS = 15000;
+    static constexpr int RESPONSE_TIMEOUT_MS = 2000;
+
+    // NVS storage
+    NVSStorageHandler* storage_;
+    static constexpr const char* NVS_NAMESPACE = "discord";
+    static constexpr const char* NVS_KEY_IP = "remote_ip";
+    static constexpr const char* NVS_KEY_PORT = "remote_port";
+
+    // Event callbacks
+    static void on_mute_button_clicked(lv_event_t* e);
+    static void on_settings_button_clicked(lv_event_t* e);
+    static void on_save_settings_clicked(lv_event_t* e);
+    static void on_test_connection_clicked(lv_event_t* e);
+
+    // UDP communication
+    void send_mute_command();
+    bool test_connection();
+    void update_status_display();
+    void show_error_notification(bool show);
+
+    // Settings management
+    void load_settings();
+    void save_settings();
+
+    // Polling task
+    static void poll_task(void* param);
+    void start_polling_task();
+    void stop_polling_task();
+    void poll_status();
+};
+
+/**
+ * @brief Discord app descriptor for registration
+ */
+class DiscordAppDescriptor : public AppDescriptor {
+public:
+    static DiscordAppDescriptor& instance() {
+        static DiscordAppDescriptor instance;
+        return instance;
+    }
+
+    void draw_icon(lv_obj_t* parent) override;
+
+private:
+    DiscordAppDescriptor();
+};

main/ui/apps/mtr_app.cpp

@@ -0,0 +1,399 @@
+#include "apps/mtr_app.h"
+#include "external/mtr/arrival.h"
+#include "esp_log.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#define TAG "MtrApp"
+
+// Event type for network ready
+#define EVENT_NETWORK_READY 1
+
+MtrApp::MtrApp() {
+  _mtr_handler = std::make_unique<MTRNextTrainHandler>();
+}
+
+esp_err_t MtrApp::init(lv_obj_t* container) {
+  if (!container) {
+    ESP_LOGE(TAG, "Container is null");
+    return ESP_ERR_INVALID_ARG;
+  }
+
+  _container = container;
+  ESP_LOGI(TAG, "Initializing MTR app...");
+
+  // Create page stack
+  _page_stack = std::make_unique<PageStack>(container);
+
+  // Load all lines
+  _all_lines = _mtr_handler->get_lines();
+  ESP_LOGI(TAG, "Loaded %zu MTR lines", _all_lines.size());
+
+  // Build initial line selection page
+  _page_stack->push([this](lv_obj_t* page) {
+    this->build_line_selection_page(page);
+    });
+
+  ESP_LOGI(TAG, "MTR app initialized successfully");
+  return ESP_OK;
+}
+
+esp_err_t MtrApp::deinit(void) {
+  ESP_LOGI(TAG, "Deinitializing MTR app");
+
+  // Clear page stack
+  if (_page_stack) {
+    _page_stack->clear();
+    _page_stack.reset();
+  }
+
+  // Clear state
+  _selected_line_code.clear();
+  _selected_station_code.clear();
+  _selected_line_info = nullptr;
+  _all_lines.clear();
+
+  return ESP_OK;
+}
+
+std::string MtrApp::get_name(void) const {
+  return "MTR";
+}
+
+bool MtrApp::on_back_button_pressed(void) {
+  if (_page_stack && _page_stack->depth() > 1) {
+    _page_stack->pop();
+    return true;  // Handled
+  }
+  return false;  // Not handled, go back to main menu
+}
+
+void MtrApp::handle_event(uint32_t event_type, void* event_data) {
+  if (event_type == EVENT_NETWORK_READY) {
+    ESP_LOGI(TAG, "Network ready event received");
+  }
+}
+
+void MtrApp::build_line_selection_page(lv_obj_t* page_container) {
+  ESP_LOGI(TAG, "Building line selection page");
+
+  // Title
+  lv_obj_t* title = lv_label_create(page_container);
+  lv_label_set_text(title, "選擇路綫 Select Line");
+  lv_obj_set_style_text_color(title, lv_color_black(), 0);
+  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);
+
+  // Scrollable container for line buttons
+  lv_obj_t* scroll_container = lv_obj_create(page_container);
+  lv_obj_set_size(scroll_container, lv_pct(95), lv_pct(85));
+  lv_obj_align(scroll_container, LV_ALIGN_TOP_MID, 0, 40);
+  lv_obj_set_flex_flow(scroll_container, LV_FLEX_FLOW_COLUMN);
+  lv_obj_set_flex_align(scroll_container, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+  lv_obj_set_style_pad_all(scroll_container, 5, 0);
+  lv_obj_set_style_pad_row(scroll_container, 8, 0);
+
+  // Create button for each line
+  for (size_t i = 0; i < _all_lines.size(); i++) {
+    LineInfo* line = &_all_lines[i];
+
+    lv_obj_t* btn = lv_btn_create(scroll_container);
+    lv_obj_set_size(btn, lv_pct(95), 60);
+
+    // Set button color based on line color
+    uint32_t color = parse_color_hex(line->color());
+    lv_obj_set_style_bg_color(btn, lv_color_hex(color), 0);
+
+    // Button label
+    lv_obj_t* label = lv_label_create(btn);
+    lv_label_set_text_fmt(label, "%s", line->code());
+    lv_obj_set_style_text_color(label, lv_color_white(), 0);
+    lv_obj_center(label);
+
+    // Store line pointer in user data
+    lv_obj_add_event_cb(btn, line_button_event_cb, LV_EVENT_CLICKED, this);
+    lv_obj_set_user_data(btn, (void*)line);
+  }
+
+  ESP_LOGI(TAG, "Created %zu line buttons", _all_lines.size());
+}
+
+void MtrApp::build_station_selection_page(lv_obj_t* page_container) {
+  ESP_LOGI(TAG, "Building station selection page for line: %s", _selected_line_code.c_str());
+
+  if (!_selected_line_info) {
+    ESP_LOGE(TAG, "No line info selected");
+    return;
+  }
+
+  // Title with line code
+  lv_obj_t* title = lv_label_create(page_container);
+  lv_label_set_text_fmt(title, "%s 路綫車站", _selected_line_code.c_str());
+  lv_obj_set_style_text_color(title, lv_color_black(), 0);
+  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);
+
+  // Scrollable container for station buttons
+  lv_obj_t* scroll_container = lv_obj_create(page_container);
+  lv_obj_set_size(scroll_container, lv_pct(95), lv_pct(85));
+  lv_obj_align(scroll_container, LV_ALIGN_TOP_MID, 0, 40);
+  lv_obj_set_flex_flow(scroll_container, LV_FLEX_FLOW_COLUMN);
+  lv_obj_set_flex_align(scroll_container, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+  lv_obj_set_style_pad_all(scroll_container, 5, 0);
+  lv_obj_set_style_pad_row(scroll_container, 6, 0);
+
+  // Create button for each station
+  const std::vector<StationInfo>* stations = _selected_line_info->stations();
+  for (size_t i = 0; i < stations->size(); i++) {
+    const StationInfo* station = &(*stations)[i];
+
+    lv_obj_t* btn = lv_btn_create(scroll_container);
+    lv_obj_set_size(btn, lv_pct(95), 50);
+    lv_obj_set_style_bg_color(btn, lv_color_hex(0x4CAF50), 0);
+
+    // Button label with station name and code
+    lv_obj_t* label = lv_label_create(btn);
+    lv_label_set_text_fmt(label, "%s (%s)", station->name(), station->code());
+    lv_obj_set_style_text_color(label, lv_color_white(), 0);
+    lv_obj_center(label);
+
+    // Store station pointer in user data
+    lv_obj_add_event_cb(btn, station_button_event_cb, LV_EVENT_CLICKED, this);
+    lv_obj_set_user_data(btn, (void*)station);
+  }
+
+  ESP_LOGI(TAG, "Created %zu station buttons", stations->size());
+}
+
+void MtrApp::build_arrival_page(lv_obj_t* page_container) {
+  ESP_LOGI(TAG, "Building arrival page");
+
+  // Title
+  lv_obj_t* title = lv_label_create(page_container);
+  lv_label_set_text_fmt(title, "%s - %s", _selected_line_code.c_str(), _selected_station_code.c_str());
+  lv_obj_set_style_text_color(title, lv_color_black(), 0);
+  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);
+
+  // Loading message
+  lv_obj_t* loading_label = lv_label_create(page_container);
+  lv_label_set_text(loading_label, "載入中... Loading...");
+  lv_obj_set_style_text_color(loading_label, lv_color_black(), 0);
+  lv_obj_center(loading_label);
+
+  // Refresh button
+  lv_obj_t* refresh_btn = lv_btn_create(page_container);
+  lv_obj_set_size(refresh_btn, 120, 50);
+  lv_obj_align(refresh_btn, LV_ALIGN_BOTTOM_MID, 0, -10);
+  lv_obj_add_event_cb(refresh_btn, refresh_button_event_cb, LV_EVENT_CLICKED, this);
+
+  lv_obj_t* refresh_label = lv_label_create(refresh_btn);
+  lv_label_set_text(refresh_label, LV_SYMBOL_REFRESH " 重新整理");
+  lv_obj_set_style_text_color(refresh_label, lv_color_white(), 0);
+  lv_obj_center(refresh_label);
+
+  // Load arrival data asynchronously
+  load_arrival_data(page_container);
+}
+
+void MtrApp::load_arrival_data(lv_obj_t* page_container) {
+  if (!_network_handler) {
+    ESP_LOGW(TAG, "Network handler not set, cannot fetch arrival data");
+    // Update UI to show error
+    lv_obj_t* error_label = lv_label_create(page_container);
+    lv_label_set_text(error_label, "網絡未就緒\nNetwork not ready");
+    lv_obj_set_style_text_color(error_label, lv_color_black(), 0);
+    lv_obj_align(error_label, LV_ALIGN_CENTER, 0, -30);
+    return;
+  }
+
+  ESP_LOGI(TAG, "Fetching arrival data for %s/%s", _selected_line_code.c_str(), _selected_station_code.c_str());
+
+  StationArrivalInfo* arrival_info = nullptr;
+  MtrArrivalErrorCode error_code = _mtr_handler->get_next_arrival_info(
+    _network_handler,
+    _selected_line_code,
+    _selected_station_code,
+    arrival_info,
+    Language::TC
+  );
+
+  // Clear loading message
+  lv_obj_clean(page_container);
+
+  // Recreate title
+  lv_obj_t* title = lv_label_create(page_container);
+  lv_label_set_text_fmt(title, "%s - %s", _selected_line_code.c_str(), _selected_station_code.c_str());
+  lv_obj_set_style_text_color(title, lv_color_black(), 0);
+  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);
+
+  if (error_code != MtrArrivalErrorCode::NONE || !arrival_info) {
+    ESP_LOGE(TAG, "Failed to fetch arrival info, error code: %d", (int)error_code);
+
+    lv_obj_t* error_label = lv_label_create(page_container);
+    lv_label_set_text(error_label, "無法取得班次資料\nFailed to fetch arrival data");
+    lv_obj_set_style_text_color(error_label, lv_color_black(), 0);
+    lv_obj_center(error_label);
+    return;
+  }
+
+  // Create scrollable container for arrivals
+  lv_obj_t* scroll_container = lv_obj_create(page_container);
+  lv_obj_set_size(scroll_container, lv_pct(95), lv_pct(75));
+  lv_obj_align(scroll_container, LV_ALIGN_TOP_MID, 0, 45);
+  lv_obj_set_style_pad_all(scroll_container, 10, 0);
+
+  int y_offset = 0;
+
+  // Display UP direction trains
+  lv_obj_t* up_header = lv_label_create(scroll_container);
+  lv_label_set_text(up_header, "上行 UP:");
+  lv_obj_set_style_text_color(up_header, lv_color_black(), 0);
+  lv_obj_set_pos(up_header, 0, y_offset);
+  y_offset += 30;
+
+  const std::vector<ArrivalInfo>* up_arrivals = arrival_info->up_arrivals();
+  if (up_arrivals->empty()) {
+    lv_obj_t* no_train = lv_label_create(scroll_container);
+    lv_label_set_text(no_train, "  暫無班次 No trains");
+    lv_obj_set_style_text_color(no_train, lv_color_hex(0x666666), 0);
+    lv_obj_set_pos(no_train, 10, y_offset);
+    y_offset += 25;
+  } else {
+    for (const auto& arrival : *up_arrivals) {
+      lv_obj_t* arrival_label = lv_label_create(scroll_container);
+      lv_label_set_text_fmt(arrival_label, "  %s → %s", arrival.arrival_time(), arrival.destination());
+      lv_obj_set_style_text_color(arrival_label, lv_color_black(), 0);
+      lv_obj_set_pos(arrival_label, 10, y_offset);
+      y_offset += 25;
+    }
+  }
+
+  y_offset += 10;
+
+  // Display DOWN direction trains
+  lv_obj_t* down_header = lv_label_create(scroll_container);
+  lv_label_set_text(down_header, "下行 DOWN:");
+  lv_obj_set_style_text_color(down_header, lv_color_black(), 0);
+  lv_obj_set_pos(down_header, 0, y_offset);
+  y_offset += 30;
+
+  const std::vector<ArrivalInfo>* down_arrivals = arrival_info->down_arrivals();
+  if (down_arrivals->empty()) {
+    lv_obj_t* no_train = lv_label_create(scroll_container);
+    lv_label_set_text(no_train, "  暫無班次 No trains");
+    lv_obj_set_style_text_color(no_train, lv_color_hex(0x666666), 0);
+    lv_obj_set_pos(no_train, 10, y_offset);
+    y_offset += 25;
+  } else {
+    for (const auto& arrival : *down_arrivals) {
+      lv_obj_t* arrival_label = lv_label_create(scroll_container);
+      lv_label_set_text_fmt(arrival_label, "  %s → %s", arrival.arrival_time(), arrival.destination());
+      lv_obj_set_style_text_color(arrival_label, lv_color_black(), 0);
+      lv_obj_set_pos(arrival_label, 10, y_offset);
+      y_offset += 25;
+    }
+  }
+
+  // Clean up
+  if (arrival_info != nullptr) {
+    delete arrival_info;
+  }
+
+  // Refresh button
+  lv_obj_t* refresh_btn = lv_btn_create(page_container);
+  lv_obj_set_size(refresh_btn, 120, 50);
+  lv_obj_align(refresh_btn, LV_ALIGN_BOTTOM_MID, 0, -10);
+  lv_obj_add_event_cb(refresh_btn, refresh_button_event_cb, LV_EVENT_CLICKED, this);
+
+  lv_obj_t* refresh_label = lv_label_create(refresh_btn);
+  lv_label_set_text(refresh_label, LV_SYMBOL_REFRESH " 重新整理");
+  lv_obj_set_style_text_color(refresh_label, lv_color_white(), 0);
+  lv_obj_center(refresh_label);
+
+  ESP_LOGI(TAG, "Arrival data displayed successfully");
+}
+
+uint32_t MtrApp::parse_color_hex(const char* hex_str) {
+  if (!hex_str || hex_str[0] != '#') {
+    return 0x808080;  // Default gray
+  }
+
+  // Skip the '#' character
+  hex_str++;
+
+  uint32_t color = 0;
+  sscanf(hex_str, "%" SCNx32, &color);
+  return color;
+}
+
+void MtrApp::line_button_event_cb(lv_event_t* e) {
+  lv_event_code_t code = lv_event_get_code(e);
+  if (code == LV_EVENT_CLICKED) {
+    MtrApp* app = (MtrApp*)lv_event_get_user_data(e);
+    lv_obj_t* btn = (lv_obj_t*)lv_event_get_target(e);
+    LineInfo* line = (LineInfo*)lv_obj_get_user_data(btn);
+
+    if (app && line) {
+      ESP_LOGI(TAG, "Line selected: %s", line->code());
+      app->_selected_line_code = line->code();
+      app->_selected_line_info = line;
+
+      // Push station selection page
+      app->_page_stack->push([app](lv_obj_t* page) {
+        app->build_station_selection_page(page);
+        });
+    }
+  }
+}
+
+void MtrApp::station_button_event_cb(lv_event_t* e) {
+  lv_event_code_t code = lv_event_get_code(e);
+  if (code == LV_EVENT_CLICKED) {
+    MtrApp* app = (MtrApp*)lv_event_get_user_data(e);
+    lv_obj_t* btn = (lv_obj_t*)lv_event_get_target(e);
+    const StationInfo* station = (const StationInfo*)lv_obj_get_user_data(btn);
+
+    if (app && station) {
+      ESP_LOGI(TAG, "Station selected: %s (%s)", station->name(), station->code());
+      app->_selected_station_code = station->code();
+
+      // Push arrival page
+      app->_page_stack->push([app](lv_obj_t* page) {
+        app->build_arrival_page(page);
+        });
+    }
+  }
+}
+
+void MtrApp::refresh_button_event_cb(lv_event_t* e) {
+  lv_event_code_t code = lv_event_get_code(e);
+  if (code == LV_EVENT_CLICKED) {
+    MtrApp* app = (MtrApp*)lv_event_get_user_data(e);
+    if (app && app->_page_stack && app->_page_stack->current_page()) {
+      ESP_LOGI(TAG, "Refresh button clicked");
+      app->load_arrival_data(app->_page_stack->current_page());
+    }
+  }
+}
+
+// MtrAppDescriptor implementation
+MtrApp* MtrAppDescriptor::_app_instance = nullptr;
+
+MtrAppDescriptor::MtrAppDescriptor()
+  : AppDescriptor("MTR", []() -> UIApp* {
+  if (!MtrAppDescriptor::_app_instance) {
+    MtrAppDescriptor::_app_instance = new MtrApp();
+  }
+  return MtrAppDescriptor::_app_instance;
+    }()) {
+  // Register with AppRegistry
+  AppRegistry::instance().register_app(this);
+  ESP_LOGI(TAG, "MtrApp registered with AppRegistry");
+}
+
+void MtrAppDescriptor::draw_icon(lv_obj_t* parent) {
+  // Create MTR icon with train symbol
+  lv_obj_t* icon_label = lv_label_create(parent);
+  lv_label_set_text(icon_label, LV_SYMBOL_GPS "\nMTR");
+  lv_obj_set_style_text_color(icon_label, lv_color_white(), 0);
+  lv_obj_set_style_text_align(icon_label, LV_TEXT_ALIGN_CENTER, 0);
+  lv_obj_center(icon_label);
+}

main/ui/apps/mtr_app.h

@@ -0,0 +1,71 @@
+#pragma once
+
+#include "ui/ui_app.h"
+#include "ui/app_registry.h"
+#include "ui/page_stack.h"
+#include "external/mtr/mtr.h"
+#include "external/mtr/line_info.h"
+#include "external/mtr/station_info.h"
+#include "network/network.h"
+#include <memory>
+#include <string>
+
+/**
+ * @brief MTR Next Train application
+ *
+ * Provides multi-page navigation for:
+ * 1. Line selection - choose MTR line
+ * 2. Station selection - choose station within selected line
+ * 3. Arrival display - show real-time train arrival information
+ */
+class MtrApp : public UIApp {
+public:
+  MtrApp();
+  virtual ~MtrApp() = default;
+
+  esp_err_t init(lv_obj_t* container) override;
+  esp_err_t deinit(void) override;
+  std::string get_name(void) const override;
+  bool on_back_button_pressed(void) override;
+  void handle_event(uint32_t event_type, void* event_data) override;
+
+  // Set network handler (must be called before using app)
+  void set_network_handler(NetworkHandler* handler) { _network_handler = handler; }
+
+private:
+  std::unique_ptr<MTRNextTrainHandler> _mtr_handler;
+  std::unique_ptr<PageStack> _page_stack;
+  NetworkHandler* _network_handler = nullptr;
+
+  // Current selection state
+  std::string _selected_line_code;
+  std::string _selected_station_code;
+  LineInfo* _selected_line_info = nullptr;
+  std::vector<LineInfo> _all_lines;
+
+  // Page builders
+  void build_line_selection_page(lv_obj_t* page_container);
+  void build_station_selection_page(lv_obj_t* page_container);
+  void build_arrival_page(lv_obj_t* page_container);
+
+  // Event handlers
+  static void line_button_event_cb(lv_event_t* e);
+  static void station_button_event_cb(lv_event_t* e);
+  static void refresh_button_event_cb(lv_event_t* e);
+
+  // Helper functions
+  void load_arrival_data(lv_obj_t* page_container);
+  uint32_t parse_color_hex(const char* hex_str);
+};
+
+/**
+ * @brief AppDescriptor for MtrApp
+ */
+class MtrAppDescriptor : public AppDescriptor {
+public:
+  MtrAppDescriptor();
+  void draw_icon(lv_obj_t* parent) override;
+
+private:
+  static MtrApp* _app_instance;
+};

main/ui/apps/registry.h

@@ -1,53 +0,0 @@
-#pragma once
-
-#include "ui/apps/app.h"
-#include <map>
-#include <string>
-#include "esp_log.h"
-#include <memory>
-
-class AppRegistry {
-public:
-  static AppRegistry& instance() {
-    static AppRegistry registry;
-    return registry;
-  }
-
-  void register_app(std::unique_ptr<AppDescriptor> app_descriptor) {
-    if (app_descriptors_.find(app_descriptor->get_name()) != app_descriptors_.end()) {
-      // App already registered
-      ESP_LOGW("AppRegistry", "App '%s' is already registered", app_descriptor->get_name().c_str());
-      return;
-    }
-    app_descriptors_.emplace(app_descriptor->get_name(), std::move(app_descriptor));
-  }
-
-  size_t size() const {
-    return app_descriptors_.size();
-  }
-
-  // iterators to access registered apps
-  auto begin() { return app_descriptors_.begin(); }
-  auto begin() const { return app_descriptors_.begin(); }
-  auto end() { return app_descriptors_.end(); }
-  auto end() const { return app_descriptors_.end(); }
-
-  // [] operator to get app by name
-  AppDescriptor* operator[](const std::string& name) {
-    auto it = app_descriptors_.find(name);
-    if (it != app_descriptors_.end()) {
-      return it->second.get();
-    }
-    return nullptr;
-  }
-
-private:
-  std::map<std::string, std::unique_ptr<AppDescriptor>> app_descriptors_ = {};
-
-  AppRegistry() = default;
-  // Disable copy and move semantics
-  AppRegistry(const AppRegistry&) = delete;
-  AppRegistry& operator=(const AppRegistry&) = delete;
-  AppRegistry(AppRegistry&&) = delete;
-  AppRegistry& operator=(AppRegistry&&) = delete;
-};

main/ui/apps/shutdown_app.cpp

@@ -0,0 +1,64 @@
+#include "apps/shutdown_app.h"
+#include "esp_log.h"
+
+#define TAG "ShutdownApp"
+
+ShutdownApp::ShutdownApp(std::string message)
+  : _message(message.empty() ? "System Shutting Down..." : message) { }
+
+esp_err_t ShutdownApp::init(lv_obj_t* container) {
+  if (!container) {
+    ESP_LOGE(TAG, "Container is null");
+    return ESP_ERR_INVALID_ARG;
+  }
+
+  _container = container;
+  ESP_LOGI(TAG, "Initializing shutdown app with message: %s", _message.c_str());
+
+  // Main message label
+  _label_message = lv_label_create(_container);
+  lv_label_set_text(_label_message, _message.c_str());
+  lv_obj_set_style_text_color(_label_message, lv_color_white(), 0);
+  lv_obj_align(_label_message, LV_ALIGN_CENTER, 0, 0);
+
+  // Optional: Add spinner animation
+  lv_obj_t* spinner = lv_spinner_create(_container);
+  lv_obj_set_size(spinner, 80, 80);
+  lv_obj_align(spinner, LV_ALIGN_CENTER, 0, 80);
+  lv_obj_set_style_arc_color(spinner, lv_color_white(), LV_PART_INDICATOR);
+
+  ESP_LOGI(TAG, "Shutdown app initialized successfully");
+  return ESP_OK;
+}
+
+esp_err_t ShutdownApp::deinit(void) {
+  ESP_LOGI(TAG, "Deinitializing shutdown app");
+  _label_message = nullptr;
+  return ESP_OK;
+}
+
+std::string ShutdownApp::get_name(void) const {
+  return "Shutdown";
+}
+
+// ShutdownAppDescriptor implementation
+ShutdownApp* ShutdownAppDescriptor::_app_instance = nullptr;
+
+ShutdownAppDescriptor::ShutdownAppDescriptor()
+  : AppDescriptor("Shutdown", nullptr) {
+  // Create singleton app instance with default message
+  if (!_app_instance) {
+    _app_instance = new ShutdownApp();
+  }
+
+  // it's only used during system shutdown, not as a user-launchable app
+}
+
+void ShutdownAppDescriptor::draw_icon(lv_obj_t* parent) {
+  // Create a simple icon (not normally shown in nav bar)
+  lv_obj_t* icon_label = lv_label_create(parent);
+  lv_label_set_text(icon_label, LV_SYMBOL_POWER "\nShutdown");
+  lv_obj_set_style_text_color(icon_label, lv_color_white(), 0);
+  lv_obj_set_style_text_align(icon_label, LV_TEXT_ALIGN_CENTER, 0);
+  lv_obj_center(icon_label);
+}

main/ui/apps/shutdown_app.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include "ui/ui_app.h"
+#include "ui/app_registry.h"
+
+/**
+ * @brief Shutdown application - displays shutdown message
+ *
+ * Shown when the system is about to enter deep sleep or power off.
+ * Displays a message and optionally a spinner animation.
+ */
+class ShutdownApp : public UIApp {
+public:
+  ShutdownApp(std::string message = "");
+  virtual ~ShutdownApp() = default;
+
+  esp_err_t init(lv_obj_t* container) override;
+  esp_err_t deinit(void) override;
+  std::string get_name(void) const override;
+
+private:
+  std::string _message;
+  lv_obj_t* _label_message = nullptr;
+};
+
+/**
+ * @brief AppDescriptor for ShutdownApp
+ *
+ * Note: Shutdown app is typically not shown in the navigation bar
+ * as it's only used during system shutdown.
+ */
+class ShutdownAppDescriptor : public AppDescriptor {
+public:
+  ShutdownAppDescriptor();
+  void draw_icon(lv_obj_t* parent) override;
+
+private:
+  static ShutdownApp* _app_instance;
+};

main/ui/events.cpp

@@ -1,4 +0,0 @@
-#include "events.h"
-
-// Define the event base
-ESP_EVENT_DEFINE_BASE(UI_EVENT_BASE);

main/ui/events.h

@@ -1,15 +0,0 @@
-#pragma once
-
-#include "esp_event.h"
-#include "lvgl.h"
-
-ESP_EVENT_DECLARE_BASE(UI_EVENT_BASE);
-
-struct KeyboardEventData {
-  lv_obj_t* textarea; ///< The textarea that triggered the keyboard event, nullptr if not applicable or for hide event
-};
-
-enum EventId {
-  UI_EVENT_KEYBOARD_SHOWN = 1,   ///< Event ID for keyboard shown event
-  UI_EVENT_KEYBOARD_HIDDEN = 2   ///< Event ID for keyboard hidden event
-};

main/ui/interaction_handler.cpp

@@ -1,159 +0,0 @@
-#include "ui/interaction_handler.h"
-#include "ui/events.h"
-#include "esp_err.h"
-#include "esp_log.h"
-
-#define TAG "InteractionHandler"
-
-InteractionHandler::~InteractionHandler() {
-  esp_err_t err = deinit();
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Error during InteractionHandler deinit: %s", esp_err_to_name(err));
-  }
-}
-
-esp_err_t InteractionHandler::init(lv_obj_t* app_container) {
-  if (!app_container) {
-    ESP_LOGE(TAG, "Invalid argument: app_container is nullptr");
-    return ESP_ERR_INVALID_ARG;
-  }
-  app_container_ = app_container;
-  keyboard_ = lv_keyboard_create(app_container_);
-  lv_obj_add_flag(keyboard_, LV_OBJ_FLAG_HIDDEN); // start hidden
-  lv_obj_add_event_cb(
-    keyboard_,
-    [](lv_event_t* e) {
-      InteractionHandler* handler = static_cast<InteractionHandler*>(lv_event_get_user_data(e));
-      handler->on_keyboard_event_(e);
-    }
-  , LV_EVENT_ALL, this);
-
-  return ESP_OK;
-}
-
-esp_err_t InteractionHandler::deinit(void) {
-  if (keyboard_) {
-    lv_obj_del(keyboard_);
-    keyboard_ = nullptr;
-  }
-  return ESP_OK;
-}
-
-esp_err_t InteractionHandler::register_text_area_keyboard_support(lv_obj_t* text_area) {
-  if (!text_area) {
-    ESP_LOGE(TAG, "Invalid argument: text_area is nullptr");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  lv_obj_add_event_cb(
-    text_area,
-    [](lv_event_t* e) {
-      lv_event_code_t code = lv_event_get_code(e);
-      if (code != LV_EVENT_FOCUSED) {
-        return;
-      }
-      InteractionHandler* handler = static_cast<InteractionHandler*>(lv_event_get_user_data(e));
-
-      esp_err_t err = handler->show_keyboard_for_textarea_(static_cast<lv_obj_t*>(lv_event_get_target(e)));
-      if (err != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to show keyboard: %s", esp_err_to_name(err));
-      }
-    }
-  , LV_EVENT_FOCUSED, this);
-
-  lv_obj_add_event_cb(
-    text_area,
-    [](lv_event_t* e) {
-      lv_event_code_t code = lv_event_get_code(e);
-      if (code != LV_EVENT_DEFOCUSED) {
-        return;
-      }
-      InteractionHandler* handler = static_cast<InteractionHandler*>(lv_event_get_user_data(e));
-
-      esp_err_t err = handler->hide_keyboard_();
-      if (err != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to hide keyboard: %s", esp_err_to_name(err));
-      }
-    }
-  , LV_EVENT_DEFOCUSED, this);
-
-  return ESP_OK;
-}
-
-//
-// Private methods
-//
-
-void InteractionHandler::on_keyboard_event_(lv_event_t* e) {
-  lv_event_code_t code = lv_event_get_code(e);
-  if (code == LV_EVENT_READY || code == LV_EVENT_CANCEL) {
-    // Keyboard is cancelled
-    esp_err_t err = hide_keyboard_();
-    if (err != ESP_OK) {
-      ESP_LOGE(TAG, "Failed to hide keyboard: %s", esp_err_to_name(err));
-    }
-
-    if (focused_textarea_) {
-      lv_obj_clear_state(focused_textarea_, LV_STATE_FOCUSED);
-      lv_keyboard_set_textarea(keyboard_, nullptr);
-      focused_textarea_ = nullptr;
-    }
-  }
-}
-
-esp_err_t InteractionHandler::show_keyboard_for_textarea_(lv_obj_t* textarea) {
-  if (!keyboard_ || !textarea) {
-    ESP_LOGE(TAG, "Invalid state or argument in show_keyboard_for_textarea_");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  focused_textarea_ = textarea;
-  lv_keyboard_set_textarea(keyboard_, textarea);
-  lv_obj_clear_flag(keyboard_, LV_OBJ_FLAG_HIDDEN);
-  // emit keyboard shown event
-  KeyboardEventData event_data = {
-   .textarea = textarea
-  };
-  esp_err_t err = esp_event_post_to(
-    NULL,
-    UI_EVENT_BASE,
-    UI_EVENT_KEYBOARD_SHOWN,
-    &event_data,
-    sizeof(event_data),
-    portMAX_DELAY
-  );
-
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to post keyboard shown event: %s", esp_err_to_name(err));
-  }
-
-  return ESP_OK;
-}
-
-esp_err_t InteractionHandler::hide_keyboard_(void) {
-  if (!keyboard_) {
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  lv_obj_add_flag(keyboard_, LV_OBJ_FLAG_HIDDEN);
-
-  // emit keyboard hidden event
-  KeyboardEventData event_data = {
-   .textarea = nullptr
-  };
-
-  esp_err_t err = esp_event_post_to(
-    NULL,
-    UI_EVENT_BASE,
-    UI_EVENT_KEYBOARD_HIDDEN,
-    &event_data,
-    sizeof(event_data),
-    portMAX_DELAY
-  );
-
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to post keyboard hidden event: %s", esp_err_to_name(err));
-  }
-
-  return ESP_OK;
-}

main/ui/interaction_handler.h

@@ -1,70 +0,0 @@
-#pragma once
-
-#include "esp_err.h"
-#include "lvgl.h"
-#include "ui/events.h"
-
-
-
-/**
- * @brief Interaction Handler - manages user interactions
- *
- * This class is responsible for handling user inputs
- * such as touch events, button presses, and gestures.
- * It routes these interactions to the appropriate UI components
- * or apps based on the current context. And it also handles the respective UI widgets.
- *
- * For example, it manages:
- * Textarea focus and display of the on-screen keyboard
- */
-class InteractionHandler {
-public:
-
-  InteractionHandler() = default;
-  ~InteractionHandler();
-
-  /**
-   * @brief Initialize the Interaction Handler
-   *
-   * Sets up necessary event listeners and state.
-   *
-   * @return ESP_OK on success, error code otherwise
-   */
-  esp_err_t init(lv_obj_t* app_container);
-
-  /**
-   * @brief Deinitialize the Interaction Handler
-   *
-   * Cleans up resources and event listeners.
-   *
-   * @return ESP_OK on success, error code otherwise
-   */
-  esp_err_t deinit(void);
-
-  /**
-   * @brief Add keyboard support to a textarea widget
-   *
-   * @param text_area Pointer to the textarea lvgl object
-   * @return esp_err_t ESP_OK on success, error code otherwise
-   */
-  esp_err_t register_text_area_keyboard_support(lv_obj_t* text_area);
-
-private:
-
-  // Event handler for keyboard show/hide events
-  // It should be registered with event callbacks of the keyboard object
-  void on_keyboard_event_(lv_event_t* e);
-
-  esp_err_t show_keyboard_for_textarea_(lv_obj_t* textarea);
-  esp_err_t hide_keyboard_(void);
-
-  // Pointers to key UI objects, owned by UIHandler
-  lv_obj_t* app_container_ = nullptr;
-  // owned keyboard object
-  lv_obj_t* keyboard_ = nullptr;
-  // Currently focused textarea, reference only
-  lv_obj_t* focused_textarea_ = nullptr;
-
-  InteractionHandler(const InteractionHandler&) = delete;
-  InteractionHandler& operator=(const InteractionHandler&) = delete;
-};

main/ui/page_stack.cpp

@@ -0,0 +1,115 @@
+#include "page_stack.h"
+#include "esp_log.h"
+
+static const char* TAG = "PageStack";
+
+PageStack::PageStack(lv_obj_t* parent_container)
+    : parent_container_(parent_container) {
+    if (!parent_container_) {
+        ESP_LOGE(TAG, "Parent container is null");
+    }
+}
+
+PageStack::~PageStack() {
+    clear();
+}
+
+lv_obj_t* PageStack::create_page_container() {
+    lv_obj_t* page = lv_obj_create(parent_container_);
+
+    // Fill parent container
+    lv_obj_set_size(page, LV_PCT(100), LV_PCT(100));
+    lv_obj_set_pos(page, 0, 0);
+
+    // Remove padding and scrollbars
+    lv_obj_set_style_pad_all(page, 0, 0);
+    lv_obj_set_scrollbar_mode(page, LV_SCROLLBAR_MODE_OFF);
+
+    // White background
+    lv_obj_set_style_bg_color(page, lv_color_white(), 0);
+    lv_obj_set_style_bg_opa(page, LV_OPA_COVER, 0);
+
+    // Remove border
+    lv_obj_set_style_border_width(page, 0, 0);
+
+    return page;
+}
+
+lv_obj_t* PageStack::push(PageBuilder builder, PageCleanup cleanup) {
+    if (!parent_container_) {
+        ESP_LOGE(TAG, "Cannot push page: parent container is null");
+        return nullptr;
+    }
+
+    if (!builder) {
+        ESP_LOGE(TAG, "Cannot push page: builder is null");
+        return nullptr;
+    }
+
+    // Hide current page if any
+    if (!pages_.empty()) {
+        lv_obj_add_flag(pages_.back().container, LV_OBJ_FLAG_HIDDEN);
+    }
+
+    // Create new page container
+    lv_obj_t* page = create_page_container();
+
+    // Build page content
+    builder(page);
+
+    // Add to stack
+    pages_.push_back({page, cleanup});
+
+    ESP_LOGD(TAG, "Pushed page (depth: %d)", pages_.size());
+    return page;
+}
+
+bool PageStack::pop() {
+    if (pages_.empty()) {
+        ESP_LOGW(TAG, "Cannot pop: stack is empty");
+        return false;
+    }
+
+    // Get and remove current page
+    Page current = pages_.back();
+    pages_.pop_back();
+
+    // Call cleanup callback if provided
+    if (current.cleanup) {
+        current.cleanup(current.container);
+    }
+
+    // Delete page container
+    lv_obj_del(current.container);
+
+    // Show previous page if any
+    if (!pages_.empty()) {
+        lv_obj_clear_flag(pages_.back().container, LV_OBJ_FLAG_HIDDEN);
+    }
+
+    ESP_LOGD(TAG, "Popped page (depth: %d)", pages_.size());
+    return true;
+}
+
+void PageStack::clear() {
+    ESP_LOGD(TAG, "Clearing all pages (depth: %d)", pages_.size());
+
+    // Pop all pages (calls cleanup callbacks)
+    while (!pages_.empty()) {
+        Page current = pages_.back();
+        pages_.pop_back();
+
+        if (current.cleanup) {
+            current.cleanup(current.container);
+        }
+
+        lv_obj_del(current.container);
+    }
+}
+
+lv_obj_t* PageStack::current_page() const {
+    if (pages_.empty()) {
+        return nullptr;
+    }
+    return pages_.back().container;
+}

main/ui/page_stack.h

@@ -0,0 +1,86 @@
+#pragma once
+
+#include "lvgl.h"
+#include <vector>
+#include <functional>
+
+/**
+ * @brief Reusable page stack for multi-page navigation within LVGL apps
+ *
+ * Manages a stack of LVGL containers, allowing apps to push/pop pages
+ * and implement hierarchical navigation. Thread-safe for use with LVGL.
+ */
+class PageStack {
+public:
+    /**
+     * @brief Page builder callback
+     * @param page_container The LVGL container to build the page in
+     */
+    using PageBuilder = std::function<void(lv_obj_t* page_container)>;
+
+    /**
+     * @brief Page cleanup callback
+     * @param page_container The LVGL container being destroyed
+     */
+    using PageCleanup = std::function<void(lv_obj_t* page_container)>;
+
+    /**
+     * @brief Construct page stack with parent container
+     * @param parent_container Parent LVGL container for pages
+     */
+    explicit PageStack(lv_obj_t* parent_container);
+
+    /**
+     * @brief Destructor - clears all pages
+     */
+    ~PageStack();
+
+    /**
+     * @brief Push a new page onto the stack
+     * @param builder Function to build page content
+     * @param cleanup Optional cleanup function called when page is popped
+     * @return The created page container
+     */
+    lv_obj_t* push(PageBuilder builder, PageCleanup cleanup = nullptr);
+
+    /**
+     * @brief Pop the current page and return to previous
+     * @return true if page was popped, false if stack is empty
+     */
+    bool pop();
+
+    /**
+     * @brief Clear all pages from the stack
+     */
+    void clear();
+
+    /**
+     * @brief Get the current (top) page container
+     * @return Current page or nullptr if stack is empty
+     */
+    lv_obj_t* current_page() const;
+
+    /**
+     * @brief Get the number of pages in the stack
+     */
+    size_t depth() const { return pages_.size(); }
+
+    /**
+     * @brief Check if stack is empty
+     */
+    bool empty() const { return pages_.empty(); }
+
+private:
+    struct Page {
+        lv_obj_t* container;
+        PageCleanup cleanup;
+    };
+
+    lv_obj_t* parent_container_;
+    std::vector<Page> pages_;
+
+    /**
+     * @brief Create a page container
+     */
+    lv_obj_t* create_page_container();
+};

main/ui/root_layout.cpp

@@ -1,93 +1,123 @@
 #include "ui/root_layout.h"
-#include "ui/events.h"
+#include "ui/ui_handler.h"
+#include "ui/app_registry.h"
 #include "esp_log.h"
-#include "esp_event.h"
 
 #define TAG "RootLayout"
 
+// Display dimensions
+#define DISPLAY_WIDTH 800
+#define DISPLAY_HEIGHT 480
+
+// Layout dimensions
 #define HEADER_HEIGHT 40
 #define NAV_BAR_HEIGHT 50
+#define APP_CONTAINER_HEIGHT (DISPLAY_HEIGHT - HEADER_HEIGHT - NAV_BAR_HEIGHT)
 
-RootLayout::~RootLayout() {
-  deinit();
+// forward-declare local event callback
+static void on_home_button_clicked(lv_event_t* event);
+
+RootLayout::RootLayout(UIHandler* ui_handler)
+  : _ui_handler(ui_handler) { }
+
+esp_err_t RootLayout::init(lv_obj_t* parent) {
+  if (!parent) {
+    ESP_LOGE(TAG, "Parent object is null");
+    return ESP_ERR_INVALID_ARG;
   }
 
-esp_err_t RootLayout::init(lv_obj_t* parent, UIHandler* ui_handler) {
+  ESP_LOGI(TAG, "Initializing RootLayout");
 
+  if (create_layout(parent) != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to create layout");
+    return ESP_FAIL;
+  }
+
+  ESP_LOGI(TAG, "RootLayout initialized successfully");
+  return ESP_OK;
+}
+
+esp_err_t RootLayout::deinit(void) {
+  ESP_LOGI(TAG, "Deinitializing RootLayout");
+
+  // LVGL will handle cleanup when parent is destroyed
+  _header = nullptr;
+  _header_label = nullptr;
+  _app_container = nullptr;
+  _nav_bar = nullptr;
+  _back_button = nullptr;
+
+  return ESP_OK;
+}
+
+esp_err_t RootLayout::create_layout(lv_obj_t* parent) {
   // Configure parent as flexbox column layout
   lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
   lv_obj_set_flex_align(parent, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_START);
   lv_obj_set_style_pad_all(parent, 0, 0);
   lv_obj_set_style_pad_gap(parent, 0, 0);
-  //
+
   // Create header (top, fixed height)
-  header_obj_ = lv_obj_create(parent);
-  lv_obj_set_width(header_obj_, lv_pct(100));
-  lv_obj_set_height(header_obj_, HEADER_HEIGHT);
-  lv_obj_set_style_bg_color(header_obj_, lv_color_white(), 0);
-  lv_obj_set_style_border_width(header_obj_, 0, 0);
-  lv_obj_set_style_border_color(header_obj_, lv_color_black(), 0);
-  lv_obj_set_style_border_width(header_obj_, 1, LV_BORDER_SIDE_BOTTOM);
-  lv_obj_set_style_pad_all(header_obj_, 0, 0);
-  lv_obj_set_style_radius(header_obj_, 0, 0);
-  //
-  header_label_ = lv_label_create(header_obj_);
-  lv_label_set_text(header_label_, "App");
-  lv_obj_set_style_text_color(header_label_, lv_color_black(), 0);
-  lv_obj_align(header_label_, LV_ALIGN_LEFT_MID, 10, 0);
-  //
-  // Create app container (middle, flexible height)
-  app_container_ = lv_obj_create(parent);
-  lv_obj_set_width(app_container_, lv_pct(100));
-  lv_obj_set_flex_grow(app_container_, 1);
-  lv_obj_set_style_bg_color(app_container_, lv_color_white(), 0);
-  lv_obj_set_style_border_width(app_container_, 0, 0);
-  lv_obj_set_style_pad_all(app_container_, 0, 0);
-  lv_obj_set_style_radius(app_container_, 0, 0);
+  _header = lv_obj_create(parent);
+  lv_obj_set_width(_header, lv_pct(100));
+  lv_obj_set_height(_header, HEADER_HEIGHT);
+  lv_obj_set_style_bg_color(_header, lv_color_hex(0xFFFFFF), 0);
+  lv_obj_set_style_border_width(_header, 0, 0);
+  lv_obj_set_style_border_color(_header, lv_color_hex(0x000000), 0);
+  lv_obj_set_style_border_width(_header, 1, LV_BORDER_SIDE_BOTTOM);
+  lv_obj_set_style_pad_all(_header, 0, 0);
+  lv_obj_set_style_radius(_header, 0, 0);
+
+  _header_label = lv_label_create(_header);
+  lv_label_set_text(_header_label, "App");
+  lv_obj_set_style_text_color(_header_label, lv_color_black(), 0);
+  lv_obj_align(_header_label, LV_ALIGN_LEFT_MID, 10, 0);
+
+  // Create app container (middle, flexible - grows to fill available space)
+  _app_container = lv_obj_create(parent);
+  lv_obj_set_width(_app_container, lv_pct(100));
+  lv_obj_set_flex_grow(_app_container, 1);
+  lv_obj_set_style_bg_color(_app_container, lv_color_white(), 0);
+  lv_obj_set_style_border_width(_app_container, 0, 0);
+  lv_obj_set_style_pad_all(_app_container, 0, 0);
+  lv_obj_set_style_radius(_app_container, 0, 0);
 
-  //
   // Create navigation bar (bottom, fixed height)
-  nav_bar_obj_ = lv_obj_create(parent);
-  lv_obj_set_width(nav_bar_obj_, lv_pct(100));
-  lv_obj_set_height(nav_bar_obj_, NAV_BAR_HEIGHT);
-  lv_obj_set_style_bg_color(nav_bar_obj_, lv_color_white(), 0);
-  lv_obj_set_style_border_color(nav_bar_obj_, lv_color_black(), 0);
-  lv_obj_set_style_border_width(nav_bar_obj_, 1, LV_BORDER_SIDE_TOP);
-  lv_obj_set_style_pad_all(nav_bar_obj_, 5, 0);
-  lv_obj_set_style_radius(nav_bar_obj_, 0, 0);
+  _nav_bar = lv_obj_create(parent);
+  lv_obj_set_width(_nav_bar, lv_pct(100));
+  lv_obj_set_height(_nav_bar, NAV_BAR_HEIGHT);
+  lv_obj_set_style_bg_color(_nav_bar, lv_color_hex(0xFFFFFF), 0);
+  lv_obj_set_style_border_color(_nav_bar, lv_color_hex(0x000000), 0);
+  lv_obj_set_style_border_width(_nav_bar, 1, LV_BORDER_SIDE_TOP);
+  lv_obj_set_style_pad_all(_nav_bar, 5, 0);
+  lv_obj_set_style_radius(_nav_bar, 0, 0);
 
+  // Configure nav bar as flexbox row layout with space-between
+  lv_obj_set_flex_flow(_nav_bar, LV_FLEX_FLOW_ROW);
+  lv_obj_set_flex_align(_nav_bar, LV_FLEX_ALIGN_SPACE_BETWEEN, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
 
   // Create back button (aligned to start by flex layout)
-  back_button_ = lv_btn_create(nav_bar_obj_);
-  lv_obj_set_size(back_button_, 60, NAV_BAR_HEIGHT - 10);
-  lv_obj_set_style_bg_color(back_button_, lv_color_white(), 0);
-  lv_obj_add_flag(back_button_, LV_OBJ_FLAG_HIDDEN);
-  lv_obj_t* back_label = lv_label_create(back_button_);
+  _back_button = lv_btn_create(_nav_bar);
+  lv_obj_set_size(_back_button, 60, NAV_BAR_HEIGHT - 10);
+  lv_obj_set_style_bg_color(_back_button, lv_color_hex(0x555555), 0);
+  lv_obj_add_event_cb(_back_button, on_back_button_clicked, LV_EVENT_CLICKED, _ui_handler);
+  lv_obj_add_flag(_back_button, LV_OBJ_FLAG_HIDDEN);
+
+  // Add back arrow label
+  lv_obj_t* back_label = lv_label_create(_back_button);
   lv_label_set_text(back_label, LV_SYMBOL_LEFT);
+  lv_obj_set_style_text_color(back_label, lv_color_black(), 0);
+  lv_obj_align(back_label, LV_ALIGN_CENTER, 0, 0);
 
   // Create home button (aligned to end by flex layout)
-  home_button_ = lv_btn_create(nav_bar_obj_);
-  lv_obj_set_size(home_button_, 60, NAV_BAR_HEIGHT - 10);
-  lv_obj_set_style_bg_color(home_button_, lv_color_white(), 0);
-  lv_obj_t* home_label = lv_label_create(home_button_);
+  lv_obj_t* home_button = lv_btn_create(_nav_bar);
+  lv_obj_set_size(home_button, 60, NAV_BAR_HEIGHT - 10);
+  lv_obj_set_style_bg_color(home_button, lv_color_hex(0x555555), 0);
+  lv_obj_t* home_label = lv_label_create(home_button);
   lv_label_set_text(home_label, LV_SYMBOL_HOME);
-  lv_obj_set_style_text_color(home_label, lv_color_black(), 0);
+  lv_obj_set_style_text_color(home_label, lv_color_white(), 0);
   lv_obj_align(home_label, LV_ALIGN_CENTER, 0, 0);
-
-  // Register keyboard event handler
-  esp_err_t err = esp_event_handler_instance_register(
-    UI_EVENT_BASE,
-    ESP_EVENT_ANY_ID,
-    [](void* handler_args, esp_event_base_t base, int32_t id, void* event_data) {
-      RootLayout* root_layout = static_cast<RootLayout*>(handler_args);
-      root_layout->on_keyboard_event_(handler_args, base, id, event_data);
-    },
-    this,
-    &keyboard_event_handler_instance_
-  );
-  if (err != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to register keyboard event handler: %s", esp_err_to_name(err));
-  }
+  lv_obj_add_event_cb(home_button, on_home_button_clicked, LV_EVENT_CLICKED, _ui_handler);
 
   ESP_LOGI(TAG, "Layout created with flexible design: Header=%d, NavBar=%d",
     HEADER_HEIGHT, NAV_BAR_HEIGHT);
@@ -95,155 +125,140 @@ esp_err_t RootLayout::init(lv_obj_t* parent, UIHandler* ui_handler) {
   return ESP_OK;
 }
 
-esp_err_t RootLayout::deinit(void) {
-  // Unregister keyboard event handler
-  if (keyboard_event_handler_instance_) {
-    esp_event_handler_instance_unregister(
-      UI_EVENT_BASE,
-      ESP_EVENT_ANY_ID,
-      keyboard_event_handler_instance_
-    );
-    keyboard_event_handler_instance_ = nullptr;
-  }
-
-  header_obj_ = nullptr;
-  header_label_ = nullptr;
-  //
-  app_container_ = nullptr;
-  //
-  nav_bar_obj_ = nullptr;
-  back_button_ = nullptr;
-  home_button_ = nullptr;
-
-  return ESP_OK;
-}
-
-void RootLayout::hide_nav_bar(void) const {
-  if (nav_bar_obj_) {
-    lv_obj_add_flag(nav_bar_obj_, LV_OBJ_FLAG_HIDDEN);
-  } else {
-    ESP_LOGW(TAG, "Navigation bar not initialized");
-  }
-}
-
-void RootLayout::show_nav_bar(void) const {
-  if (nav_bar_obj_) {
-    lv_obj_clear_flag(nav_bar_obj_, LV_OBJ_FLAG_HIDDEN);
-  } else {
-    ESP_LOGW(TAG, "Navigation bar not initialized");
-  }
-}
-
-void RootLayout::show_back_button(void) const {
-  if (back_button_) {
-    lv_obj_clear_flag(back_button_, LV_OBJ_FLAG_HIDDEN);
-  } else {
-    ESP_LOGW(TAG, "Back button not initialized");
-  }
-}
-
-void RootLayout::show_home_button(void) const {
-  if (home_button_) {
-    lv_obj_clear_flag(home_button_, LV_OBJ_FLAG_HIDDEN);
-  } else {
-    ESP_LOGW(TAG, "Home button not found in navigation bar");
-  }
-}
-
-void RootLayout::hide_back_button(void) const {
-  if (back_button_) {
-    lv_obj_add_flag(back_button_, LV_OBJ_FLAG_HIDDEN);
-  } else {
-    ESP_LOGW(TAG, "Back button not initialized");
-  }
-}
-
-void RootLayout::hide_home_button(void) const {
-  if (home_button_) {
-    lv_obj_add_flag(home_button_, LV_OBJ_FLAG_HIDDEN);
-  } else {
-    ESP_LOGW(TAG, "Home button not found in navigation bar");
-  }
-}
-
-esp_err_t RootLayout::register_back_button_callback(lv_event_cb_t callback, void* user_data, lv_event_dsc_t** out_event_dsc) const {
-  if (!back_button_) {
-    ESP_LOGE(TAG, "Back button not initialized");
-    return ESP_ERR_INVALID_STATE;
-  }
-  if (!callback) {
-    ESP_LOGE(TAG, "Invalid argument: callback is nullptr");
-    return ESP_ERR_INVALID_ARG;
-  }
-  if (out_event_dsc == nullptr) {
-    ESP_LOGE(TAG, "Invalid argument: out_event_dsc is nullptr");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  *out_event_dsc = lv_obj_add_event_cb(back_button_, callback, LV_EVENT_CLICKED, user_data);
-
-  if (*out_event_dsc == nullptr) {
-    ESP_LOGE(TAG, "Failed to register back button callback");
-    return ESP_FAIL;
-  }
-
-  return ESP_OK;
-}
-
-esp_err_t RootLayout::register_home_button_callback(lv_event_cb_t callback, void* user_data, lv_event_dsc_t** out_event_dsc) const {
-  if (!home_button_) {
-    ESP_LOGE(TAG, "Home button not found in navigation bar");
-    return ESP_ERR_NOT_FOUND;
-  }
-  if (!callback) {
-    ESP_LOGE(TAG, "Invalid argument: callback is nullptr");
-    return ESP_ERR_INVALID_ARG;
-  }
-  if (out_event_dsc == nullptr) {
-    ESP_LOGE(TAG, "Invalid argument: out_event_dsc is nullptr");
-    return ESP_ERR_INVALID_ARG;
-  }
-
-  *out_event_dsc = lv_obj_add_event_cb(home_button_, callback, LV_EVENT_CLICKED, user_data);
-
-  if (*out_event_dsc == nullptr) {
-    ESP_LOGE(TAG, "Failed to register home button callback");
-    return ESP_FAIL;
-  }
-
-  return ESP_OK;
-}
-
-esp_err_t RootLayout::update_header(const std::string& title) const {
-  if (!header_label_) {
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  if (title.empty() == false) {
-    lv_label_set_text(header_label_, title.c_str());
-  } else {
-    lv_label_set_text(header_label_, "App");
-  }
-
-  return ESP_OK;
-}
-
-void RootLayout::on_keyboard_event_(void* handler_args, esp_event_base_t base, int32_t id, void* event_data) {
-  if (base != UI_EVENT_BASE) {
+void RootLayout::update_header(std::string app_name) {
+  if (!_header_label) {
     return;
   }
 
-  switch (id) {
-    case UI_EVENT_KEYBOARD_SHOWN:
-      hide_nav_bar();
-      break;
-
-    case UI_EVENT_KEYBOARD_HIDDEN:
-      show_nav_bar();
-      break;
-
-    default:
-      ESP_LOGW(TAG, "Unknown keyboard event ID: %ld", id);
-      break;
+  if (app_name.empty() == false) {
+    lv_label_set_text(_header_label, app_name.c_str());
+  } else {
+    lv_label_set_text(_header_label, "App");
   }
 }
+
+esp_err_t RootLayout::render_app_icons(void) {
+  if (!_nav_bar) {
+    ESP_LOGE(TAG, "Navigation bar not initialized");
+    return ESP_FAIL;
+  }
+
+  // Clear existing app container content (icons are rendered in the app area)
+  if (!_app_container) {
+    ESP_LOGE(TAG, "App container not initialized");
+    return ESP_FAIL;
+  }
+  lv_obj_clean(_app_container);
+
+  // Get all registered apps from registry
+  const auto& app_descriptors = AppRegistry::instance().get_app_descriptors();
+
+  if (app_descriptors.empty()) {
+    ESP_LOGW(TAG, "No apps registered in AppRegistry");
+    lv_obj_t* nav_label = lv_label_create(_nav_bar);
+    lv_label_set_text(nav_label, "No apps available");
+    lv_obj_set_style_text_color(nav_label, lv_color_white(), 0);
+    lv_obj_align(nav_label, LV_ALIGN_CENTER, 0, 0);
+    return ESP_OK;
+  }
+
+  ESP_LOGI(TAG, "Rendering %d app icons", (int)app_descriptors.size());
+
+  // Calculate icon spacing inside the app container
+  int icon_count = app_descriptors.size();
+  int icon_width = 96;
+  int icon_height = 96;
+  int icon_spacing = DISPLAY_WIDTH / (icon_count + 1);
+  int x_offset = icon_spacing;
+  int y_offset = (APP_CONTAINER_HEIGHT - icon_height) / 2;
+
+  // Render each app icon into the app container
+  for (size_t i = 0; i < app_descriptors.size(); i++) {
+    AppDescriptor* descriptor = app_descriptors[i];
+
+    lv_obj_t* icon_container = lv_obj_create(_app_container);
+    lv_obj_set_size(icon_container, icon_width, icon_height);
+    lv_obj_set_pos(icon_container, x_offset - icon_width / 2, y_offset);
+    lv_obj_set_style_bg_opa(icon_container, LV_OPA_TRANSP, 0);
+    lv_obj_set_style_pad_all(icon_container, 0, 0);
+    // add a border for debugging
+    lv_obj_set_style_border_color(icon_container, lv_color_hex(0x000000), 0);
+    lv_obj_set_style_border_width(icon_container, 1, 0);
+
+    lv_obj_set_user_data(icon_container, descriptor);
+
+    descriptor->draw_icon(icon_container);
+
+    lv_obj_add_flag(icon_container, LV_OBJ_FLAG_CLICKABLE);
+    lv_obj_add_event_cb(icon_container, on_app_icon_clicked, LV_EVENT_CLICKED, _ui_handler);
+
+    x_offset += icon_spacing;
+  }
+
+  return ESP_OK;
+}
+
+void RootLayout::show_back_button(void) {
+  if (_back_button) {
+    lv_obj_clear_flag(_back_button, LV_OBJ_FLAG_HIDDEN);
+  }
+}
+
+void RootLayout::hide_back_button(void) {
+  if (_back_button) {
+    lv_obj_add_flag(_back_button, LV_OBJ_FLAG_HIDDEN);
+  }
+}
+
+void RootLayout::on_app_icon_clicked(lv_event_t* event) {
+  // Use the current target (the object the callback was attached to)
+  // instead of the event target, which may be a child (like a label).
+  lv_obj_t* icon_container = static_cast<lv_obj_t*>(lv_event_get_current_target(event));
+  UIHandler* handler = static_cast<UIHandler*>(lv_event_get_user_data(event));
+  AppDescriptor* descriptor = static_cast<AppDescriptor*>(lv_obj_get_user_data(icon_container));
+
+  if (!handler || !descriptor) {
+    ESP_LOGE(TAG, "Invalid event data in app icon click");
+    return;
+  }
+
+  ESP_LOGI(TAG, "App icon clicked: %s", descriptor->get_name().c_str());
+  handler->switch_app(descriptor);
+}
+
+void RootLayout::on_back_button_clicked(lv_event_t* event) {
+  UIHandler* handler = static_cast<UIHandler*>(lv_event_get_user_data(event));
+
+  if (!handler) {
+    ESP_LOGE(TAG, "Invalid handler in back button click");
+    return;
+  }
+
+  // Get the active app
+  UIApp* active_app = handler->get_active_app();
+  if (!active_app) {
+    ESP_LOGW(TAG, "Back button pressed but no active app");
+    return;
+  }
+
+  // Let the app handle the back button press
+  bool handled = active_app->on_back_button_pressed();
+
+  if (handled) {
+    ESP_LOGI(TAG, "Back button handled by app: %s", active_app->get_name());
+  } else {
+    ESP_LOGI(TAG, "Back button not handled by app, returning to main screen");
+    handler->return_to_main_screen();
+  }
+}
+
+static void on_home_button_clicked(lv_event_t* event) {
+  UIHandler* handler = static_cast<UIHandler*>(lv_event_get_user_data(event));
+
+  if (!handler) {
+    ESP_LOGE(TAG, "Invalid handler in home button click");
+    return;
+  }
+
+  handler->return_to_main_screen();
+}

main/ui/root_layout.h

@@ -1,126 +1,138 @@
 #pragma once
-#include "esp_err.h"
-#include "esp_event.h"
+
 #include "lvgl.h"
+#include "esp_err.h"
 #include <string>
 
-// Forward declaration to avoid circular dependency
+// Forward declaration
 class UIHandler;
 
+/**
+ * @brief Root Layout Manager - manages the main screen layout
+ *
+ * The RootLayout class is responsible for:
+ * - Creating and managing the main screen structure (header, app container, nav bar)
+ * - Rendering app icons from the AppRegistry
+ * - Managing the back button
+ * - Updating header content
+ */
 class RootLayout {
 public:
-  RootLayout() = default;
-  ~RootLayout();
+  /**
+   * @brief Construct a new RootLayout object
+   *
+   * @param ui_handler Pointer to the UIHandler (for callbacks)
+   */
+  RootLayout(UIHandler* ui_handler);
 
   /**
-   * @brief Initialize the root layout within the given parent object
+   * @brief Initialize the layout
    *
-   * Sets up the header, app container, and navigation bar.
+   * Creates the main screen with header, app container, and navigation bar.
    *
-   * @param parent Parent LVGL object to contain the layout
+   * @param parent Parent LVGL object to attach layout to
    * @return ESP_OK on success, error code otherwise
    */
-  esp_err_t init(lv_obj_t* parent, UIHandler* ui_handler);
+  esp_err_t init(lv_obj_t* parent);
 
   /**
-   * @brief Deinitialize the root layout
+   * @brief Deinitialize the layout
    *
-   * Cleans up references to layout components.
+   * Cleans up all layout widgets.
    *
    * @return ESP_OK on success, error code otherwise
    */
   esp_err_t deinit(void);
 
   /**
-   * @brief Show the back button in the navigation bar
-   */
-  void show_back_button(void) const;
-
-  /**
-   * @brief Hide the back button in the navigation bar
-   */
-  void hide_back_button(void) const;
-
-  /**
-   * @brief Show the home button in the navigation bar
-   */
-  void show_home_button(void) const;
-
-  /**
-   * @brief Hide the home button in the navigation bar
-   */
-  void hide_home_button(void) const;
-
-  /**
-   * @brief Show navigation bar
+   * @brief Render app icons in the navigation bar
    *
-   */
-  void show_nav_bar(void) const;
-
-  /**
-   * @brief Hide navigation bar
+   * Queries the AppRegistry for all registered apps and
+   * renders their icons in the navigation bar. Also creates
+   * the back button.
    *
-   */
-  void hide_nav_bar(void) const;
-
-
-
-
-  /**
-   * @brief Register a callback for back button presses
-   *
-   *
-   * @param callback
-   * @param user_data
-   * @param out_event_dsc
    * @return ESP_OK on success, error code otherwise
    */
-  esp_err_t register_back_button_callback(lv_event_cb_t callback, void* user_data, lv_event_dsc_t** out_event_dsc) const;
+  esp_err_t render_app_icons(void);
 
   /**
-   * @brief Register a callback for home button presses
+   * @brief Update header with app name
    *
-   * @param callback
-   * @param user_data
-   * @param out_event_dsc
-   * @return ESP_OK on success, error code otherwise
+   * @param app_name Name to display in header (nullptr for default)
    */
-  esp_err_t register_home_button_callback(lv_event_cb_t callback, void* user_data, lv_event_dsc_t** out_event_dsc) const;
+  void update_header(std::string app_name);
 
   /**
-   * @brief Update the header title text
-   *
-   * @param title New title text
-   * @return ESP_OK on success, error code otherwise
+   * @brief Show the back button
    */
-  esp_err_t update_header(const std::string& title) const;
+  void show_back_button(void);
 
   /**
-   * @brief Get the app container object, which holds the active app's UI
-   * Caller can add/remove app UI elements to/from this container.
-   * Caller must not delete this object directly or edit its layout properties.
-   *
-   * @return lv_obj_t*
+   * @brief Hide the back button
    */
-  lv_obj_t* get_app_container() const {
-    return app_container_;
+  void hide_back_button(void);
+
+  /**
+   * @brief Get the header object
+   *
+   * @return lv_obj_t* pointer to the header container
+   */
+  lv_obj_t* get_header(void) const {
+    return _header;
+  }
+
+  /**
+   * @brief Get the app container (where apps render)
+   *
+   * @return lv_obj_t* pointer to the app container
+   */
+  lv_obj_t* get_app_container(void) const {
+    return _app_container;
+  }
+
+  /**
+   * @brief Get the navigation bar object
+   *
+   * @return lv_obj_t* pointer to the navigation bar container
+   */
+  lv_obj_t* get_nav_bar(void) const {
+    return _nav_bar;
   }
 
 private:
+  UIHandler* _ui_handler = nullptr;      ///< Reference to UIHandler for callbacks
+  lv_obj_t* _header = nullptr;           ///< Header area (top)
+  lv_obj_t* _header_label = nullptr;     ///< Header text label
+  lv_obj_t* _app_container = nullptr;    ///< Container for app widgets (middle)
+  lv_obj_t* _nav_bar = nullptr;          ///< Navigation bar (bottom)
+  lv_obj_t* _back_button = nullptr;      ///< Back button in navigation bar
 
-  // Event handler for keyboard show/hide events
-  void on_keyboard_event_(void* handler_args, esp_event_base_t base, int32_t id, void* event_data);
+  /**
+   * @brief Create the layout structure
+   *
+   * Sets up header, app container, and navigation bar with
+   * appropriate dimensions and positioning.
+   *
+   * @param parent Parent object to attach layout to
+   * @return ESP_OK on success, error code otherwise
+   */
+  esp_err_t create_layout(lv_obj_t* parent);
 
-  // layout objects
-  // header
-  lv_obj_t* header_obj_ = nullptr;      ///< Header area object
-  lv_obj_t* header_label_ = nullptr;  ///< Header title label
-  // app container
-  lv_obj_t* app_container_ = nullptr;   ///< App container object
-  // navigation bar
-  lv_obj_t* nav_bar_obj_ = nullptr;     ///< Navigation bar object
-  lv_obj_t* back_button_ = nullptr;     ///< Back button object
-  lv_obj_t* home_button_ = nullptr;    ///< Home button object
+  /**
+   * @brief Handle app icon click event
+   *
+   * Static callback for LVGL event handling.
+   *
+   * @param event LVGL event object
+   */
+  static void on_app_icon_clicked(lv_event_t* event);
 
-  esp_event_handler_instance_t keyboard_event_handler_instance_ = nullptr; ///< Event handler instance for keyboard events
+  /**
+   * @brief Handle back button click event
+   *
+   * Static callback for LVGL event handling.
+   *
+   * @param event LVGL event object
+   */
+  static void on_back_button_clicked(lv_event_t* event);
 };

main/ui/ui_app.h

@@ -3,7 +3,6 @@
 #include "lvgl.h"
 #include "esp_err.h"
 #include <string>
-#include <memory>
 
 /**
  * @brief Base class for all UI applications
@@ -49,39 +48,51 @@ public:
   virtual std::string get_name(void) const = 0;
 
   /**
-   * @brief Handle back button press
+   * @brief Handle system events passed from UIHandler
    *
-   * Called when the back button is pressed.
-   * The app can choose to handle it (e.g., close a dialog)
-   * or return false to let UIHandler handle it (e.g., return to main screen).
+   * System events include network status changes, storage ready,
+   * display refresh, and other system-level events.
    *
-   * @return true if the event was handled, false otherwise
+   * @param event_type Type/ID of the event
+   * @param event_data Optional event data payload
    */
+  virtual void handle_event(uint32_t event_type, void* event_data = nullptr) { }
+
   virtual bool on_back_button_pressed(void) {
     return false; // default: not handled
   }
 
+  /**
+   * @brief Get the app's root container
+   *
+   * @return lv_obj_t* pointer to the app's container
+   */
+  lv_obj_t* get_container(void) const {
+    return _container;
+  }
+
 protected:
-  lv_obj_t* container_ = nullptr;  ///< LVGL container provided by UIHandler
+  lv_obj_t* _container = nullptr;  ///< LVGL container provided by UIHandler
 };
 
+
 class AppDescriptor {
 public:
   virtual ~AppDescriptor() = default;
   virtual void draw_icon(lv_obj_t* parent) = 0;
 
   std::string get_name() const {
-    return name_;
+    return _name;
   }
 
   UIApp* get_app_instance() const {
-    return app_instance_.get();
+    return _app_instance;
   }
 
 protected:
-  AppDescriptor(std::string name, std::unique_ptr<UIApp> app_instance)
-    : name_(name), app_instance_(std::move(app_instance)) { }
+  AppDescriptor(std::string name, UIApp* app_instance)
+    : _name(name), _app_instance(app_instance) { }
 
-  std::string name_;
-  std::unique_ptr<UIApp> app_instance_;
+  std::string _name;
+  UIApp* _app_instance;
 };

main/ui/ui_handler.cpp

@@ -1,288 +1,208 @@
 #include "ui/ui_handler.h"
+#include "ui/root_layout.h"
+#include "ui/app_registry.h"
 #include "esp_log.h"
+#include "lvgl.h"
 
 #define TAG "UIHandler"
 
-UIHandler::~UIHandler() {
-  deinit();
-}
+// Display dimensions from constants.h
+#define DISPLAY_WIDTH 800
+#define DISPLAY_HEIGHT 480
+
+// Layout dimensions
+#define HEADER_HEIGHT 40
+#define NAV_BAR_HEIGHT 50
+#define _APP_CONTAINERHEIGHT (DISPLAY_HEIGHT - HEADER_HEIGHT - NAV_BAR_HEIGHT)
 
 esp_err_t UIHandler::init(void) {
-  lv_obj_t* screen = lv_scr_act();
-  esp_err_t ret = ESP_OK;
+  ESP_LOGI(TAG, "Initializing UIHandler");
 
-  // Create main screen layout
-  ret = create_main_screen_(screen);
-  if (ret != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to create main screen layout");
-    return ret;
+  // Create main screen
+  _main_screen = lv_obj_create(NULL);
+  if (!_main_screen) {
+    ESP_LOGE(TAG, "Failed to create main screen");
+    return ESP_FAIL;
+  }
+  lv_obj_set_style_bg_color(_main_screen, lv_color_black(), 0);
+  lv_obj_set_size(_main_screen, DISPLAY_WIDTH, DISPLAY_HEIGHT);
+
+  // Create root layout
+  _root_layout = new RootLayout(this);
+  if (!_root_layout) {
+    ESP_LOGE(TAG, "Failed to allocate RootLayout");
+    return ESP_FAIL;
   }
 
-  ret = interaction_handler_.init(root_layout_.get_app_container());
-  if (ret != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize InteractionHandler");
-    return ret;
+  if (_root_layout->init(_main_screen) != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to initialize root layout");
+    delete _root_layout;
+    _root_layout = nullptr;
+    return ESP_FAIL;
   }
 
-  // Show the main screen
-  lv_scr_load(screen);
+  // Render app icons from registry
+  if (_root_layout->render_app_icons() != ESP_OK) {
+    ESP_LOGW(TAG, "Failed to render app icons");
+  }
 
-  return ret;
+  // Defer screen loading to prevent blocking during initialization
+  // Use LVGL timer to load screen after allowing watchdog reset
+  lv_timer_create([](lv_timer_t* timer) {
+    lv_obj_t* screen = static_cast<lv_obj_t*>(lv_timer_get_user_data(timer));
+    ESP_LOGI("UIHandler", "Loading main screen via timer");
+    lv_screen_load(screen);
+    lv_timer_del(timer);
+    }, 100, _main_screen);  // 100ms delay to allow watchdog reset
+
+  ESP_LOGI(TAG, "UIHandler initialized successfully");
+  return ESP_OK;
 }
 
 esp_err_t UIHandler::deinit(void) {
-  // Deinitialize current app if any
-  if (active_descriptor_) {
-    UIApp* app = active_descriptor_->get_app_instance();
-    if (app) {
-      esp_err_t ret = app->deinit();
-      if (ret != ESP_OK) {
-        ESP_LOGE("UIHandler", "Failed to deinitialize current app");
-        return ret;
+  ESP_LOGI(TAG, "Deinitializing UIHandler");
+
+  // Deinit current app
+  if (_active_app) {
+    if (_active_app->deinit() != ESP_OK) {
+      ESP_LOGW(TAG, "Error deinitializing active app: %s", _active_app->get_name());
     }
-    }
-    active_descriptor_ = nullptr;
+    _active_app = nullptr;
   }
 
-  // Destroy main screen layout
-  esp_err_t ret = destroy_main_screen_();
-  if (ret != ESP_OK) {
-    ESP_LOGE("UIHandler", "Failed to destroy main screen layout");
-    return ret;
+  // Delete shutdown app if cached
+  if (_shutdown_app) {
+    delete _shutdown_app;
+    _shutdown_app = nullptr;
   }
 
-  // Deinitialize interaction handler
-  ret = interaction_handler_.deinit();
-  if (ret != ESP_OK) {
-    ESP_LOGE("UIHandler", "Failed to deinitialize InteractionHandler");
-    return ret;
+  // Clean up root layout
+  if (_root_layout) {
+    _root_layout->deinit();
+    delete _root_layout;
+    _root_layout = nullptr;
   }
 
+  // Main screen will be cleaned up by LVGL
+  _main_screen = nullptr;
+
   return ESP_OK;
 }
 
-esp_err_t UIHandler::switch_app(std::shared_ptr<AppDescriptor> app_descriptor) {
-  if (!app_descriptor) {
-    ESP_LOGE(TAG, "Invalid app descriptor");
+esp_err_t UIHandler::switch_app(UIApp* app) {
+  if (!app) {
+    ESP_LOGE(TAG, "Cannot switch to null app");
     return ESP_ERR_INVALID_ARG;
   }
 
-  esp_err_t ret = ESP_OK;
-
-  // Deinitialize current app if any
-  if (active_descriptor_) {
-    UIApp* current_app = active_descriptor_->get_app_instance();
-    if (current_app) {
-      ret = current_app->deinit();
-      if (ret != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to deinitialize current app");
+  lv_obj_t* app_container = get_app_container();
+  if (!app_container) {
+    ESP_LOGE(TAG, "App container not initialized");
+    return ESP_FAIL;
   }
+
+  ESP_LOGI(TAG, "Switching to app: %s", app->get_name());
+
+  // Deinit current app
+  if (_active_app) {
+    if (_active_app->deinit() != ESP_OK) {
+      ESP_LOGW(TAG, "Error deinitializing app: %s", _active_app->get_name());
     }
   }
 
   // Clear the app container
-  lv_obj_t* app_container = root_layout_.get_app_container();
-  if (app_container) {
   lv_obj_clean(app_container);
-  } else {
-    ESP_LOGE(TAG, "App container not available");
-    return ESP_ERR_INVALID_STATE;
+
+  // Initialize new app
+  if (app->init(app_container) != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to initialize app: %s", app->get_name());
+    _active_app = nullptr;
+    return ESP_FAIL;
   }
 
-  // Set the new app as active
-  active_descriptor_ = app_descriptor;
+  _active_app = app;
 
-  // Initialize the new app
-  UIApp* new_app = active_descriptor_->get_app_instance();
-  if (!new_app) {
-    ESP_LOGE(TAG, "App instance not available");
-    active_descriptor_ = nullptr;
-    return ESP_ERR_INVALID_STATE;
+  // Update header through RootLayout
+  if (_root_layout) {
+    _root_layout->update_header(_active_app->get_name());
+    _root_layout->show_back_button();
   }
 
-  ret = new_app->init(app_container);
-  if (ret != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize app: %s", new_app->get_name().c_str());
-    active_descriptor_ = nullptr;
-    return ret;
-  }
-
-  // Update header with app name
-  ret = update_header_title(new_app->get_name());
-  if (ret != ESP_OK) {
-    ESP_LOGW(TAG, "Failed to update header title");
-  }
-
-  // Show back button when in an app
-  root_layout_.show_back_button();
-
-  ESP_LOGI(TAG, "Switched to app: %s", new_app->get_name().c_str());
-
   return ESP_OK;
 }
 
-esp_err_t UIHandler::show_shutdown_screen(const std::string& message) {
-  // Deinitialize current app if any
-  if (active_descriptor_) {
-    UIApp* app = active_descriptor_->get_app_instance();
-    if (app) {
-      app->deinit();
+esp_err_t UIHandler::switch_app(AppDescriptor* app_descriptor) {
+  if (!app_descriptor) {
+    ESP_LOGE(TAG, "Cannot switch to null app descriptor");
+    return ESP_ERR_INVALID_ARG;
   }
-    active_descriptor_ = nullptr;
+
+  UIApp* app = app_descriptor->get_app_instance();
+  if (!app) {
+    ESP_LOGE(TAG, "App descriptor has null app instance");
+    return ESP_ERR_INVALID_ARG;
   }
 
+  return switch_app(app);
+}
+
+void UIHandler::route_event(uint32_t event_type, void* event_data) {
+  if (_active_app) {
+    _active_app->handle_event(event_type, event_data);
+  }
+}
+
+esp_err_t UIHandler::show_shutdown_screen(std::string message) {
+  ESP_LOGI(TAG, "Showing shutdown screen");
+
+  lv_obj_t* app_container = get_app_container();
+  if (!app_container) {
+    ESP_LOGE(TAG, "App container not initialized");
+    return ESP_FAIL;
+  }
+
+  // Clear current app reference
+  _active_app = nullptr;
+
   // Clear the app container
-  lv_obj_t* app_container = root_layout_.get_app_container();
-  if (app_container) {
   lv_obj_clean(app_container);
 
-    // Create a simple shutdown message screen
-    lv_obj_t* label = lv_label_create(app_container);
-    if (message.empty()) {
-      lv_label_set_text(label, "Shutting down...");
-    } else {
-      lv_label_set_text(label, message.c_str());
+  // Create shutdown message
+  lv_obj_t* shutdown_label = lv_label_create(app_container);
+  lv_label_set_text(shutdown_label, message.empty() ? "Shutting down..." : message.c_str());
+  lv_obj_set_style_text_color(shutdown_label, lv_color_white(), 0);
+  lv_obj_align(shutdown_label, LV_ALIGN_CENTER, 0, 0);
+
+  // Update header through RootLayout
+  if (_root_layout) {
+    _root_layout->update_header("System Shutdown");
   }
-    lv_obj_set_style_text_font(label, &lv_font_montserrat_14, 0);
-    lv_obj_center(label);
-  }
-
-  // Update header
-  update_header_title("System");
-
-  // Hide navigation buttons
-  root_layout_.hide_back_button();
-  root_layout_.hide_home_button();
-
-  ESP_LOGI(TAG, "Showing shutdown screen: %s", message.c_str());
 
   return ESP_OK;
 }
 
 esp_err_t UIHandler::return_to_main_screen(void) {
-  esp_err_t ret = ESP_OK;
+  ESP_LOGI(TAG, "Returning to main screen");
 
-  // Deinitialize current app if any
-  if (active_descriptor_) {
-    UIApp* app = active_descriptor_->get_app_instance();
-    if (app) {
-      ret = app->deinit();
-      if (ret != ESP_OK) {
-        ESP_LOGE(TAG, "Failed to deinitialize app");
-        return ret;
+  // Deinit current app
+  if (_active_app) {
+    if (_active_app->deinit() != ESP_OK) {
+      ESP_LOGW(TAG, "Error deinitializing app: %s", _active_app->get_name());
     }
-    }
-    active_descriptor_ = nullptr;
+    _active_app = nullptr;
   }
 
   // Clear the app container
-  lv_obj_t* app_container = root_layout_.get_app_container();
+  lv_obj_t* app_container = get_app_container();
   if (app_container) {
     lv_obj_clean(app_container);
-
-    // TODO: Display app launcher/home screen with app icons
-    // For now, just show a placeholder message
-    lv_obj_t* label = lv_label_create(app_container);
-    lv_label_set_text(label, "Home Screen\n\nApp icons will go here");
-    lv_obj_set_style_text_align(label, LV_TEXT_ALIGN_CENTER, 0);
-    lv_obj_center(label);
-  } else {
-    ESP_LOGE(TAG, "App container not available");
-    return ESP_ERR_INVALID_STATE;
   }
 
-  // Update header
-  ret = update_header_title("Home");
-  if (ret != ESP_OK) {
-    ESP_LOGW(TAG, "Failed to update header title");
+  // Update header and hide back button through RootLayout
+  if (_root_layout) {
+    _root_layout->update_header("");
+    _root_layout->hide_back_button();
   }
 
-  // Hide back button on home screen
-  root_layout_.hide_back_button();
-
-  ESP_LOGI(TAG, "Returned to main screen");
-
   return ESP_OK;
 }
-
-esp_err_t UIHandler::update_header_title(const std::string& title) {
-  return root_layout_.update_header(title);
-}
-
-//
-// Private methods
-//
-
-void UIHandler::on_back_button_pressed_(void) {
-
-  if (active_descriptor_) {
-    UIApp* app = active_descriptor_->get_app_instance();
-    if (app) {
-      bool handled = app->on_back_button_pressed();
-      if (!handled) {
-        // App didn't handle it, return to main screen
-        return_to_main_screen();
-      }
-    }
-  } else {
-    ESP_LOGW(TAG, "Back button pressed but no active app");
-  }
-}
-
-esp_err_t UIHandler::create_main_screen_(lv_obj_t* parent) {
-  esp_err_t ret = ESP_OK;
-
-  // Initialize root layout
-  ret = root_layout_.init(parent, this);
-  if (ret != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to initialize RootLayout");
-    return ret;
-  }
-
-  // Register back button callback
-  lv_event_dsc_t* back_event_dsc = nullptr;
-  ret = root_layout_.register_back_button_callback(
-    [](lv_event_t* e) {
-      UIHandler* ui_handler = static_cast<UIHandler*>(lv_event_get_user_data(e));
-      ui_handler->on_back_button_pressed_();
-    },
-    this,
-    &back_event_dsc
-  );
-  if (ret != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to register back button callback");
-    return ret;
-  }
-
-  // Register home button callback
-  lv_event_dsc_t* home_event_dsc = nullptr;
-  ret = root_layout_.register_home_button_callback(
-    [](lv_event_t* e) {
-      UIHandler* ui_handler = static_cast<UIHandler*>(lv_event_get_user_data(e));
-      ui_handler->return_to_main_screen();
-    },
-    this,
-    &home_event_dsc
-  );
-  if (ret != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to register home button callback");
-    return ret;
-  }
-
-  ESP_LOGI(TAG, "Main screen layout created successfully");
-
-  return ESP_OK;
-}
-
-esp_err_t UIHandler::destroy_main_screen_(void) {
-  esp_err_t ret = root_layout_.deinit();
-  if (ret != ESP_OK) {
-    ESP_LOGE(TAG, "Failed to deinitialize RootLayout");
-    return ret;
-  }
-
-  ESP_LOGI(TAG, "Main screen layout destroyed successfully");
-  return ESP_OK;
-}
-
-

main/ui/ui_handler.h

@@ -1,12 +1,12 @@
 #pragma once
 
+#include "ui_app.h"
+#include "app_registry.h"
+#include "root_layout.h"
 #include "esp_err.h"
-#include "ui/apps/app.h"
-#include "ui/events.h"
-#include "ui/root_layout.h"
-#include "ui/interaction_handler.h"
-#include "lvgl.h"
-#include <memory>
+
+// Forward declaration
+class RootLayout;
 
 /**
  * @brief UI Handler - manages app lifecycle and rendering
@@ -20,10 +20,6 @@
  */
 class UIHandler {
 public:
-
-  UIHandler() = default;
-  ~UIHandler();
-
   /**
    * @brief Initialize the UI system with default layout
    *
@@ -32,10 +28,6 @@ public:
    * - App container (middle)
    * - Navigation bar (bottom)
    *
-   * And display the main screen.
-   *
-   * And initializes the InteractionHandler, callbacks, etc.
-   *
    * @return ESP_OK on success, error code otherwise
    */
   esp_err_t init(void);
@@ -50,16 +42,45 @@ public:
   esp_err_t deinit(void);
 
   /**
-   * @brief Switch to a new app by its descriptor
+   * @brief Switch to a new app
    *
    * Deinitializes the current app (if any), initializes the new app,
-   * and updates the display. Holds shared ownership of the descriptor
-   * to ensure the app remains valid while active.
+   * and updates the display.
    *
-   * @param app_descriptor Shared pointer to the app descriptor
+   * @param app Pointer to the new app to switch to
    * @return ESP_OK on success, error code otherwise
    */
-  esp_err_t switch_app(std::shared_ptr<AppDescriptor> app_descriptor);
+  esp_err_t switch_app(UIApp* app);
+
+  /**
+   * @brief Switch to an app by its descriptor
+   *
+   * Convenience method that extracts the UIApp from the descriptor
+   * and calls switch_app().
+   *
+   * @param app_descriptor Pointer to the app descriptor
+   * @return ESP_OK on success, error code otherwise
+   */
+  esp_err_t switch_app(AppDescriptor* app_descriptor);
+
+  /**
+   * @brief Get the currently active app
+   *
+   * @return Pointer to the active UIApp, or nullptr if none
+   */
+  UIApp* get_active_app(void) const {
+    return _active_app;
+  }
+
+  /**
+   * @brief Route a system event to the active app
+   *
+   * If an app is active, this forwards the event to it.
+   *
+   * @param event_type Type/ID of the event
+   * @param event_data Optional event data payload
+   */
+  void route_event(uint32_t event_type, void* event_data = nullptr);
 
   /**
    * @brief Display shutdown screen
@@ -70,7 +91,7 @@ public:
    * @param message Optional message to display (e.g., "Shutting down...")
    * @return ESP_OK on success, error code otherwise
    */
-  esp_err_t show_shutdown_screen(const std::string& message = "");
+  esp_err_t show_shutdown_screen(std::string message = "");
 
   /**
    * @brief Get the main screen object
@@ -78,10 +99,35 @@ public:
    * @return lv_obj_t* pointer to the main screen
    */
   lv_obj_t* get_main_screen(void) const {
-    return main_screen_;
+    return _main_screen;
   }
 
-  esp_err_t update_header_title(const std::string& title);
+  /**
+   * @brief Get the app container (where apps render)
+   *
+   * @return lv_obj_t* pointer to the app container
+   */
+  lv_obj_t* get_app_container(void) const {
+    return _root_layout ? _root_layout->get_app_container() : nullptr;
+  }
+
+  /**
+   * @brief Get the header object
+   *
+   * @return lv_obj_t* pointer to the header container
+   */
+  lv_obj_t* get_header(void) const {
+    return _root_layout ? _root_layout->get_header() : nullptr;
+  }
+
+  /**
+   * @brief Get the navigation bar object
+   *
+   * @return lv_obj_t* pointer to the navigation bar container
+   */
+  lv_obj_t* get_nav_bar(void) const {
+    return _root_layout ? _root_layout->get_nav_bar() : nullptr;
+  }
 
   /**
    * @brief Return to main screen (deinit app and show app icons)
@@ -94,25 +140,8 @@ public:
   esp_err_t return_to_main_screen(void);
 
 private:
-
-  // Handle back button press, route to active app if any
-  void on_back_button_pressed_(void);
-
-  // Helper to create the main screen layout
-  esp_err_t create_main_screen_(lv_obj_t* parent);
-
-  // Helper to destroy the main screen layout
-  esp_err_t destroy_main_screen_(void);
-
-  // delete copy constructor and assignment operator
-  // to prevent copying of the UIHandler instance
-  UIHandler(const UIHandler&) = delete;
-  UIHandler& operator=(const UIHandler&) = delete;
-
-
-  InteractionHandler interaction_handler_;  ///< Manages user interactions
-
-  lv_obj_t* main_screen_ = nullptr;    ///< Root screen
-  RootLayout root_layout_;            ///< Main screen layout manager
-  std::shared_ptr<AppDescriptor> active_descriptor_ = nullptr;  ///< Currently active app descriptor (shared ownership)
+  lv_obj_t* _main_screen = nullptr;    ///< Root screen
+  RootLayout* _root_layout = nullptr;  ///< Root layout manager
+  UIApp* _active_app = nullptr;        ///< Currently active app
+  UIApp* _shutdown_app = nullptr;      ///< Cached shutdown app
 };

main/ui/widgets/textarea.cpp

@@ -1,10 +0,0 @@
-#include "ui/widgets/textarea.h"
-
-lv_obj_t* textarea_create(lv_obj_t* parent) {
-  lv_obj_t* textarea = lv_textarea_create(parent);
-  // disable animations for cursor and selection for instant response
-  lv_obj_set_style_anim_time(textarea, 0, LV_PART_CURSOR | LV_STATE_FOCUSED);
-
-  return textarea;
-}
-

main/ui/widgets/textarea.h

@@ -1,4 +0,0 @@
-#pragma once
-#include "lvgl.h"
-
-lv_obj_t* textarea_create(lv_obj_t* parent);

partitions.csv

@@ -1,12 +0,0 @@
-# Name,   Type, SubType,  Offset,   Size,       Flags
-# NVS 256KB
-nvs,      data, nvs,      ,         0x40000,
-# OTA Data 8KB
-otadata,  data, ota,      ,         0x2000,
-# PHY Init 4KB
-phy_init, data, phy,      ,         0x1000,
-# OTA Partitions 10MB
-ota_0,    app,  ota_0,    ,         0xA00000,
-ota_1,    app,  ota_1,    ,         0xA00000,
-# LittleFS 11MB
-storage,  data, littlefs,     ,         0xB00000,

sdkconfig.default

@@ -430,9 +430,9 @@ CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE=y
 # end of Recovery Bootloader and Rollback
 
 CONFIG_BOOTLOADER_OFFSET_IN_FLASH=0x0
-# CONFIG_BOOTLOADER_COMPILER_OPTIMIZATION_SIZE is not set
+CONFIG_BOOTLOADER_COMPILER_OPTIMIZATION_SIZE=y
 # CONFIG_BOOTLOADER_COMPILER_OPTIMIZATION_DEBUG is not set
-CONFIG_BOOTLOADER_COMPILER_OPTIMIZATION_PERF=y
+# CONFIG_BOOTLOADER_COMPILER_OPTIMIZATION_PERF is not set
 # CONFIG_BOOTLOADER_COMPILER_OPTIMIZATION_NONE is not set
 
 #
@@ -469,7 +469,8 @@ CONFIG_BOOTLOADER_LOG_MODE_TEXT=y
 # CONFIG_BOOTLOADER_FLASH_DC_AWARE is not set
 CONFIG_BOOTLOADER_FLASH_XMC_SUPPORT=y
 CONFIG_BOOTLOADER_FLASH_32BIT_ADDR=y
-CONFIG_BOOTLOADER_CACHE_32BIT_ADDR_OCTAL_FLASH=y
+CONFIG_BOOTLOADER_FLASH_NEEDS_32BIT_FEAT=y
+CONFIG_BOOTLOADER_FLASH_NEEDS_32BIT_ADDR_QUAD_FLASH=y
 # end of Serial Flash Configurations
 
 CONFIG_BOOTLOADER_VDDSDIO_BOOST_1_9V=y
@@ -551,12 +552,14 @@ CONFIG_BOOT_ROM_LOG_ALWAYS_ON=y
 # Serial flasher config
 #
 # CONFIG_ESPTOOLPY_NO_STUB is not set
-CONFIG_ESPTOOLPY_OCT_FLASH=y
+# CONFIG_ESPTOOLPY_OCT_FLASH is not set
 CONFIG_ESPTOOLPY_FLASH_MODE_AUTO_DETECT=y
-CONFIG_ESPTOOLPY_FLASHMODE_OPI=y
+# CONFIG_ESPTOOLPY_FLASHMODE_QIO is not set
+# CONFIG_ESPTOOLPY_FLASHMODE_QOUT is not set
+CONFIG_ESPTOOLPY_FLASHMODE_DIO=y
+# CONFIG_ESPTOOLPY_FLASHMODE_DOUT is not set
 CONFIG_ESPTOOLPY_FLASH_SAMPLE_MODE_STR=y
-# CONFIG_ESPTOOLPY_FLASH_SAMPLE_MODE_DTR is not set
-CONFIG_ESPTOOLPY_FLASHMODE="dout"
+CONFIG_ESPTOOLPY_FLASHMODE="dio"
 # CONFIG_ESPTOOLPY_FLASHFREQ_120M is not set
 CONFIG_ESPTOOLPY_FLASHFREQ_80M=y
 # CONFIG_ESPTOOLPY_FLASHFREQ_40M is not set
@@ -587,10 +590,10 @@ CONFIG_ESPTOOLPY_MONITOR_BAUD=115200
 # CONFIG_PARTITION_TABLE_SINGLE_APP is not set
 # CONFIG_PARTITION_TABLE_SINGLE_APP_LARGE is not set
 # CONFIG_PARTITION_TABLE_TWO_OTA is not set
-# CONFIG_PARTITION_TABLE_TWO_OTA_LARGE is not set
-CONFIG_PARTITION_TABLE_CUSTOM=y
+CONFIG_PARTITION_TABLE_TWO_OTA_LARGE=y
+# CONFIG_PARTITION_TABLE_CUSTOM is not set
 CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"
-CONFIG_PARTITION_TABLE_FILENAME="partitions.csv"
+CONFIG_PARTITION_TABLE_FILENAME="partitions_two_ota_large.csv"
 CONFIG_PARTITION_TABLE_OFFSET=0x8000
 CONFIG_PARTITION_TABLE_MD5=y
 # end of Partition Table
@@ -1105,14 +1108,14 @@ CONFIG_SPIRAM_SPEED=80
 CONFIG_SPIRAM_BOOT_HW_INIT=y
 CONFIG_SPIRAM_BOOT_INIT=y
 CONFIG_SPIRAM_PRE_CONFIGURE_MEMORY_PROTECTION=y
-# CONFIG_SPIRAM_IGNORE_NOTFOUND is not set
+CONFIG_SPIRAM_IGNORE_NOTFOUND=y
 # CONFIG_SPIRAM_USE_MEMMAP is not set
 # CONFIG_SPIRAM_USE_CAPS_ALLOC is not set
 CONFIG_SPIRAM_USE_MALLOC=y
-CONFIG_SPIRAM_MEMTEST=y
+# CONFIG_SPIRAM_MEMTEST is not set
 CONFIG_SPIRAM_MALLOC_ALWAYSINTERNAL=16384
 CONFIG_SPIRAM_TRY_ALLOCATE_WIFI_LWIP=y
-CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL=65536
+CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL=32768
 # CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY is not set
 # CONFIG_SPIRAM_ALLOW_NOINIT_SEG_EXTERNAL_MEMORY is not set
 # end of SPI RAM config
@@ -1266,9 +1269,9 @@ CONFIG_ESP_WIFI_ENABLED=y
 CONFIG_ESP_WIFI_STATIC_RX_BUFFER_NUM=10
 CONFIG_ESP_WIFI_DYNAMIC_RX_BUFFER_NUM=32
 CONFIG_ESP_WIFI_STATIC_TX_BUFFER=y
+# CONFIG_ESP_WIFI_DYNAMIC_TX_BUFFER is not set
 CONFIG_ESP_WIFI_TX_BUFFER_TYPE=0
 CONFIG_ESP_WIFI_STATIC_TX_BUFFER_NUM=16
-CONFIG_ESP_WIFI_CACHE_TX_BUFFER_NUM=32
 CONFIG_ESP_WIFI_STATIC_RX_MGMT_BUFFER=y
 # CONFIG_ESP_WIFI_DYNAMIC_RX_MGMT_BUFFER is not set
 CONFIG_ESP_WIFI_DYNAMIC_RX_MGMT_BUF=0
@@ -1278,15 +1281,14 @@ CONFIG_ESP_WIFI_AMPDU_TX_ENABLED=y
 CONFIG_ESP_WIFI_TX_BA_WIN=6
 CONFIG_ESP_WIFI_AMPDU_RX_ENABLED=y
 CONFIG_ESP_WIFI_RX_BA_WIN=6
-# CONFIG_ESP_WIFI_AMSDU_TX_ENABLED is not set
 CONFIG_ESP_WIFI_NVS_ENABLED=y
 # CONFIG_ESP_WIFI_TASK_PINNED_TO_CORE_0 is not set
 CONFIG_ESP_WIFI_TASK_PINNED_TO_CORE_1=y
 CONFIG_ESP_WIFI_SOFTAP_BEACON_MAX_LEN=752
 CONFIG_ESP_WIFI_MGMT_SBUF_NUM=32
-# CONFIG_ESP_WIFI_IRAM_OPT is not set
+CONFIG_ESP_WIFI_IRAM_OPT=y
 # CONFIG_ESP_WIFI_EXTRA_IRAM_OPT is not set
-# CONFIG_ESP_WIFI_RX_IRAM_OPT is not set
+CONFIG_ESP_WIFI_RX_IRAM_OPT=y
 CONFIG_ESP_WIFI_ENABLE_WPA3_SAE=y
 CONFIG_ESP_WIFI_ENABLE_SAE_PK=y
 CONFIG_ESP_WIFI_ENABLE_SAE_H2E=y
@@ -1566,7 +1568,6 @@ CONFIG_LWIP_TCP_OOSEQ_MAX_PBUFS=4
 CONFIG_LWIP_TCP_OVERSIZE_MSS=y
 # CONFIG_LWIP_TCP_OVERSIZE_QUARTER_MSS is not set
 # CONFIG_LWIP_TCP_OVERSIZE_DISABLE is not set
-# CONFIG_LWIP_WND_SCALE is not set
 CONFIG_LWIP_TCP_RTO_TIME=1500
 # end of TCP
 
@@ -1670,9 +1671,9 @@ CONFIG_LWIP_HOOK_IP6_INPUT_DEFAULT=y
 #
 # mbedTLS
 #
-# CONFIG_MBEDTLS_INTERNAL_MEM_ALLOC is not set
+CONFIG_MBEDTLS_INTERNAL_MEM_ALLOC=y
 # CONFIG_MBEDTLS_EXTERNAL_MEM_ALLOC is not set
-CONFIG_MBEDTLS_DEFAULT_MEM_ALLOC=y
+# CONFIG_MBEDTLS_DEFAULT_MEM_ALLOC is not set
 # CONFIG_MBEDTLS_CUSTOM_MEM_ALLOC is not set
 CONFIG_MBEDTLS_ASYMMETRIC_CONTENT_LEN=y
 CONFIG_MBEDTLS_SSL_IN_CONTENT_LEN=16384
@@ -1834,7 +1835,7 @@ CONFIG_STDATOMIC_S32C1I_SPIRAM_WORKAROUND=y
 # CONFIG_NVS_ENCRYPTION is not set
 # CONFIG_NVS_ASSERT_ERROR_CHECK is not set
 # CONFIG_NVS_LEGACY_DUP_KEYS_COMPATIBILITY is not set
-CONFIG_NVS_ALLOCATE_CACHE_IN_SPIRAM=y
+# CONFIG_NVS_ALLOCATE_CACHE_IN_SPIRAM is not set
 # end of NVS
 
 #
@@ -1876,6 +1877,12 @@ CONFIG_SPI_FLASH_BROWNOUT_RESET=y
 #
 # Features here require specific hardware (READ DOCS FIRST!)
 #
+# CONFIG_SPI_FLASH_HPM_ENA is not set
+CONFIG_SPI_FLASH_HPM_AUTO=y
+# CONFIG_SPI_FLASH_HPM_DIS is not set
+CONFIG_SPI_FLASH_HPM_ON=y
+CONFIG_SPI_FLASH_HPM_DC_AUTO=y
+# CONFIG_SPI_FLASH_HPM_DC_DISABLE is not set
 # CONFIG_SPI_FLASH_AUTO_SUSPEND is not set
 CONFIG_SPI_FLASH_SUSPEND_TSUS_VAL_US=50
 # CONFIG_SPI_FLASH_FORCE_ENABLE_XMC_C_SUSPEND is not set
@@ -1890,6 +1897,7 @@ CONFIG_SPI_FLASH_PLACE_FUNCTIONS_IN_IRAM=y
 # CONFIG_SPI_FLASH_VERIFY_WRITE is not set
 # CONFIG_SPI_FLASH_ENABLE_COUNTERS is not set
 CONFIG_SPI_FLASH_ROM_DRIVER_PATCH=y
+# CONFIG_SPI_FLASH_ROM_IMPL is not set
 CONFIG_SPI_FLASH_DANGEROUS_WRITE_ABORTS=y
 # CONFIG_SPI_FLASH_DANGEROUS_WRITE_FAILS is not set
 # CONFIG_SPI_FLASH_DANGEROUS_WRITE_ALLOWED is not set
@@ -1969,36 +1977,6 @@ CONFIG_ESP_LCD_TOUCH_MAX_BUTTONS=1
 #
 # end of ESP LVGL PORT
 
-#
-# LittleFS
-#
-# CONFIG_LITTLEFS_SDMMC_SUPPORT is not set
-CONFIG_LITTLEFS_MAX_PARTITIONS=3
-CONFIG_LITTLEFS_PAGE_SIZE=256
-CONFIG_LITTLEFS_OBJ_NAME_LEN=64
-CONFIG_LITTLEFS_READ_SIZE=128
-CONFIG_LITTLEFS_WRITE_SIZE=128
-CONFIG_LITTLEFS_LOOKAHEAD_SIZE=128
-CONFIG_LITTLEFS_CACHE_SIZE=512
-CONFIG_LITTLEFS_BLOCK_CYCLES=512
-CONFIG_LITTLEFS_USE_MTIME=y
-# CONFIG_LITTLEFS_USE_ONLY_HASH is not set
-CONFIG_LITTLEFS_HUMAN_READABLE=y
-CONFIG_LITTLEFS_MTIME_USE_SECONDS=y
-# CONFIG_LITTLEFS_MTIME_USE_NONCE is not set
-# CONFIG_LITTLEFS_SPIFFS_COMPAT is not set
-# CONFIG_LITTLEFS_FLUSH_FILE_EVERY_WRITE is not set
-# CONFIG_LITTLEFS_FCNTL_GET_PATH is not set
-# CONFIG_LITTLEFS_MULTIVERSION is not set
-# CONFIG_LITTLEFS_MALLOC_STRATEGY_DISABLE is not set
-CONFIG_LITTLEFS_MALLOC_STRATEGY_DEFAULT=y
-# CONFIG_LITTLEFS_MALLOC_STRATEGY_INTERNAL is not set
-# CONFIG_LITTLEFS_MALLOC_STRATEGY_SPIRAM is not set
-CONFIG_LITTLEFS_ASSERTS=y
-# CONFIG_LITTLEFS_MMAP_PARTITION is not set
-# CONFIG_LITTLEFS_WDT_RESET is not set
-# end of LittleFS
-
 #
 # LVGL configuration
 #
@@ -2303,10 +2281,10 @@ CONFIG_LV_USE_WIN=y
 #
 CONFIG_LV_USE_THEME_DEFAULT=y
 # CONFIG_LV_THEME_DEFAULT_DARK is not set
-# CONFIG_LV_THEME_DEFAULT_GROW is not set
-CONFIG_LV_THEME_DEFAULT_TRANSITION_TIME=0
+CONFIG_LV_THEME_DEFAULT_GROW=y
+CONFIG_LV_THEME_DEFAULT_TRANSITION_TIME=80
 CONFIG_LV_USE_THEME_SIMPLE=y
-CONFIG_LV_USE_THEME_MONO=y
+# CONFIG_LV_USE_THEME_MONO is not set
 # end of Themes
 
 #
@@ -2426,8 +2404,11 @@ CONFIG_LOG_BOOTLOADER_LEVEL_INFO=y
 # CONFIG_LOG_BOOTLOADER_LEVEL_DEBUG is not set
 # CONFIG_LOG_BOOTLOADER_LEVEL_VERBOSE is not set
 CONFIG_LOG_BOOTLOADER_LEVEL=3
-CONFIG_SPI_FLASH_OCTAL_32BIT_ADDR_ENABLE=y
 # CONFIG_FLASH_ENCRYPTION_ENABLED is not set
+# CONFIG_FLASHMODE_QIO is not set
+# CONFIG_FLASHMODE_QOUT is not set
+CONFIG_FLASHMODE_DIO=y
+# CONFIG_FLASHMODE_DOUT is not set
 CONFIG_MONITOR_BAUD=115200
 # CONFIG_OPTIMIZATION_LEVEL_DEBUG is not set
 # CONFIG_COMPILER_OPTIMIZATION_LEVEL_DEBUG is not set
@@ -2520,22 +2501,21 @@ CONFIG_ESP32_WIFI_ENABLED=y
 CONFIG_ESP32_WIFI_STATIC_RX_BUFFER_NUM=10
 CONFIG_ESP32_WIFI_DYNAMIC_RX_BUFFER_NUM=32
 CONFIG_ESP32_WIFI_STATIC_TX_BUFFER=y
+# CONFIG_ESP32_WIFI_DYNAMIC_TX_BUFFER is not set
 CONFIG_ESP32_WIFI_TX_BUFFER_TYPE=0
 CONFIG_ESP32_WIFI_STATIC_TX_BUFFER_NUM=16
-CONFIG_ESP32_WIFI_CACHE_TX_BUFFER_NUM=32
 # CONFIG_ESP32_WIFI_CSI_ENABLED is not set
 CONFIG_ESP32_WIFI_AMPDU_TX_ENABLED=y
 CONFIG_ESP32_WIFI_TX_BA_WIN=6
 CONFIG_ESP32_WIFI_AMPDU_RX_ENABLED=y
 CONFIG_ESP32_WIFI_RX_BA_WIN=6
-# CONFIG_ESP32_WIFI_AMSDU_TX_ENABLED is not set
 CONFIG_ESP32_WIFI_NVS_ENABLED=y
 # CONFIG_ESP32_WIFI_TASK_PINNED_TO_CORE_0 is not set
 CONFIG_ESP32_WIFI_TASK_PINNED_TO_CORE_1=y
 CONFIG_ESP32_WIFI_SOFTAP_BEACON_MAX_LEN=752
 CONFIG_ESP32_WIFI_MGMT_SBUF_NUM=32
-# CONFIG_ESP32_WIFI_IRAM_OPT is not set
-# CONFIG_ESP32_WIFI_RX_IRAM_OPT is not set
+CONFIG_ESP32_WIFI_IRAM_OPT=y
+CONFIG_ESP32_WIFI_RX_IRAM_OPT=y
 CONFIG_ESP32_WIFI_ENABLE_WPA3_SAE=y
 CONFIG_ESP32_WIFI_ENABLE_WPA3_OWE_STA=y
 CONFIG_WPA_MBEDTLS_CRYPTO=y