ink-board/main/display/display.cpp

#include "display/display.h"
#include "common/constants.h"
#include "esp_log.h"

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);
  xSemaphoreTake(_spi_mutex, portMAX_DELAY);
  _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);
  xSemaphoreTake(_spi_mutex, portMAX_DELAY);
  _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);
  xSemaphoreTake(_spi_mutex, portMAX_DELAY);
  _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
  ESP_LOGI("DisplayHandler", "Waiting for EPD to be ready...");
  while (gpio_get_level(PIN_BUSY) == 0) {  // 0=BUSY, 1=FREE
    vTaskDelay(pdMS_TO_TICKS(10));
  }
  ESP_LOGI("DisplayHandler", "EPD is ready.");
  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);

  esp_lcd_touch_config_t tp_cfg = {};
  tp_cfg.x_max = 800;
  tp_cfg.y_max = 480;
  tp_cfg.rst_gpio_num = PIN_RST;
  tp_cfg.int_gpio_num = PIN_TOUCH_IRQ;

  esp_lcd_touch_new_i2c_gt911(_tp_io_handle, &tp_cfg, &_tp_handle);
  ESP_LOGI("DisplayHandler", "GT911 touch controller initialized");
}