飛書文檔https://x509p6c8to.feishu.cn/wiki/Syy3wsqHLiIiQJkC6PucEJ7Snib

ESP 系列芯片可以支持市場上常見的 LCD（如 SPI LCD、I2C LCD、并行 LCD (Intel 8080)、RGB/SRGB LCD、MIPI DSI LCD 等）所需的各種時序。esp_lcd 控制器為上述各類 LCD 提供了一個統一的抽象驅動框架。

更多支持的接口例程可以查看：esp-idf/examples/peripherals/lcd

在開發LCD類應用時，我們可以優先選擇IDF自帶了部分驅動，例如NT35510 SSD1306 ST7789，這部分驅動位于esp-idf/components/esp_lcd中，或者，我們也可以在組件庫中查找，例如gc9a01

https://components.espressif.com/components?q=esp_lcd_gc9a01

這些驅動都是適配了esp_lcd控制器的，使用起來非常方便。

如果以上兩個方法都找不到對應驅動呢？這時候就需要我們自己寫了，有兩種辦法，

第一種是比較傳統的，是把廠家提供的驅動文件，修改為ESP32的接口，例如SPI、IO相關的函數，這部分可以參考我們SPI課程中，使用SPI適配的ST7789屏幕驅動。

第二種是推薦大家用的，把驅動按esp_lcd框架的方式封裝，找接近的芯片，更改部分參數即可，例如找不到ST7789的，我們可以找ST77916的，一般同一個廠家一系列的芯片，差異點只在初始化參數的不同。

https://components.espressif.com/components?q=esp_lcd_st

最終參考esp-idf/examples/peripherals/lcd/spi_lcd_touch實現的驅動：

步驟如下

1. 初始化背光IO
2. 初始化LCD的SPI配置
3. 初始化其它顯示IO
4. 初始化ST7789驅動
5. 設置屏幕顯示方向顏色，打開背光
6. 使用繪制函數繪制圖像esp_lcd_panel_draw_bitmap

初始化背光IO

?? gpio_config_t bk_gpio_config = {.mode = GPIO_MODE_OUTPUT, // 設置GPIO模式為輸出.pin_bit_mask = 1ULL << EXAMPLE_PIN_NUM_BK_LIGHT // 設置背光控制引腳};ESP_ERROR_CHECK(gpio_config(&bk_gpio_config)); // 配置GPIO

初始化LCD的SPI配置

?? spi_bus_config_t buscfg = {.sclk_io_num = EXAMPLE_PIN_NUM_SCLK, // SCLK引腳編號.mosi_io_num = EXAMPLE_PIN_NUM_MOSI, // MOSI引腳編號.miso_io_num = GPIO_NUM_NC,????????? // MISO引腳編號.quadwp_io_num = GPIO_NUM_NC,??????? // QUADWP引腳編號（未使用）.quadhd_io_num = GPIO_NUM_NC,??????? // QUADHD引腳編號（未使用）.max_transfer_sz = EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES * sizeof(uint16_t), // 最大傳輸大小};ESP_ERROR_CHECK(spi_bus_initialize(LCD_HOST, &buscfg, SPI_DMA_CH_AUTO)); // 初始化SPI總線

初始化其它顯示IO

?? ESP_LOGI(TAG, "Install panel IO");esp_lcd_panel_io_handle_t io_handle = NULL;esp_lcd_panel_io_spi_config_t io_config = {.dc_gpio_num = EXAMPLE_PIN_NUM_LCD_DC, // 數據/命令控制引腳編號.cs_gpio_num = EXAMPLE_PIN_NUM_LCD_CS, // 片選引腳編號.pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ, // 像素時鐘頻率.lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS, // 命令位數.lcd_param_bits = EXAMPLE_LCD_PARAM_BITS, // 參數位數.spi_mode = 3, // SPI模式.trans_queue_depth = 10, // 傳輸隊列深度};// 將LCD連接到SPI總線ESP_ERROR_CHECK(esp_lcd_new_panel_io_spi((esp_lcd_spi_bus_handle_t)LCD_HOST, &io_config, &io_handle));

初始化ST7789驅動

?? // 安裝st7789面板驅動esp_lcd_panel_handle_t panel_handle = NULL;esp_lcd_panel_dev_config_t panel_config = {.reset_gpio_num = EXAMPLE_PIN_NUM_LCD_RST,? // 復位引腳編號.rgb_ele_order = LCD_RGB_ELEMENT_ORDER_RGB, // RGB元素順序.bits_per_pixel = 16,?????????????????????? // 每像素位數.data_endian = LCD_RGB_DATA_ENDIAN_BIG,???? // MSB};ESP_LOGI(TAG, "Install st7789 panel driver");ESP_ERROR_CHECK(esp_lcd_new_panel_st7789(io_handle, &panel_config, &panel_handle));

設置屏幕顯示方向顏色，打開背光

?? // 復位和初始化面板ESP_ERROR_CHECK(esp_lcd_panel_reset(panel_handle)); // 復位面板ESP_ERROR_CHECK(esp_lcd_panel_init(panel_handle)); // 初始化面板ESP_ERROR_CHECK(esp_lcd_panel_invert_color(panel_handle, true)); // 反轉顏色ESP_ERROR_CHECK(esp_lcd_panel_mirror(panel_handle, true, false)); // 鏡像顯示（水平鏡像）// 用戶可以在點亮屏幕或背光之前刷新預定義的圖案到屏幕上ESP_ERROR_CHECK(esp_lcd_panel_disp_on_off(panel_handle, true)); // 打開屏幕顯示// 打開LCD背光ESP_LOGI(TAG, "Turn on LCD backlight");gpio_set_level(EXAMPLE_PIN_NUM_BK_LIGHT, EXAMPLE_LCD_BK_LIGHT_ON_LEVEL); // 設置背光引腳電平

使用繪制函數繪制圖像esp_lcd_panel_draw_bitmap

// 設置液晶屏顏色
void lcd_set_color(uint16_t color)
{// 分配內存 這里分配了液晶屏一行數據需要的大小uint16_t *buffer = (uint16_t *)heap_caps_malloc(EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES * sizeof(uint16_t), MALLOC_CAP_8BIT | MALLOC_CAP_INTERNAL);if (NULL == buffer){ESP_LOGE(TAG, "Memory for bitmap is not enough");}else{for (size_t i = 0; i < EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES; i++) // 給緩存中放入顏色數據{buffer[i] = color;}esp_lcd_panel_draw_bitmap(panel_handle, 0 + X_OFFSET, 0, EXAMPLE_LCD_H_RES + X_OFFSET, EXAMPLE_LCD_V_RES, buffer);free(buffer); // 釋放內存}
}

SPI屏幕

SPI屏幕使用的驅動芯片是ST7789，這個驅動芯片支持的分辨率是240*320，據廠家手冊說明可知，由于是異形屏幕，屏幕的分辨率是172*320，所以驅動芯片左右兩邊分別有34列((240-172)/2) = 34是沒有接到屏幕的，所以我們設置顯示地址是，要偏移34列，屏幕接線部分如下：

從原理圖可知：

SPI SCLK為GPIO_NUM_16
SPI MOSI為GPIO_NUM_17
SPI MISO不需要
LCD_DC為GPIO_NUM_21
LCD_RST為GPIO_NUM_18
LCD_CS為GPIO_NUM_15
背光IO為GPIO_NUM_2，背光有效電平為低電平

具體代碼如下

#include <stdio.h>
#include <unistd.h>
#include <sys/lock.h>
#include <sys/param.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_lcd_panel_io.h"
#include "esp_lcd_panel_vendor.h"
#include "esp_lcd_panel_ops.h"
#include "driver/gpio.h"
#include "driver/spi_master.h"
#include "esp_err.h"
#include "esp_log.h"static const char *TAG = "example";// Using SPI2 in the example
#define LCD_HOST? SPI2_HOSTPlease update the following configuration according to your LCD spec //#define EXAMPLE_LCD_PIXEL_CLOCK_HZ???? (20 * 1000 * 1000)
#define EXAMPLE_LCD_BK_LIGHT_ON_LEVEL? 0
#define EXAMPLE_LCD_BK_LIGHT_OFF_LEVEL !EXAMPLE_LCD_BK_LIGHT_ON_LEVEL#define EXAMPLE_PIN_NUM_SCLK?????????? GPIO_NUM_16
#define EXAMPLE_PIN_NUM_MOSI?????????? GPIO_NUM_17
#define EXAMPLE_PIN_NUM_MISO?????????? GPIO_NUM_NC
#define EXAMPLE_PIN_NUM_LCD_DC ????????GPIO_NUM_21
#define EXAMPLE_PIN_NUM_LCD_RST??????? GPIO_NUM_18
#define EXAMPLE_PIN_NUM_LCD_CS???????? GPIO_NUM_15
#define EXAMPLE_PIN_NUM_BK_LIGHT?????? GPIO_NUM_2// The pixel number in horizontal and vertical
#define EXAMPLE_LCD_H_RES????????????? 172
// Bit number used to represent command and parameter
#define EXAMPLE_LCD_V_RES????????????? 320
#define EXAMPLE_LCD_CMD_BITS?????????? 8
#define EXAMPLE_LCD_PARAM_BITS???????? 8// 列地址偏移示例（假設X起始偏移為0，Y起始偏移為40）
#define X_OFFSET 34
#define Y_OFFSET 0
#define Y_OFFSET_NUM 0esp_lcd_panel_handle_t panel_handle = NULL;typedef struct {int cmd;??????????????? /*<! The specific LCD command */const void *data;?????? /*<! Buffer that holds the command specific data */size_t data_bytes;????? /*<! Size of `data` in memory, in bytes */unsigned int delay_ms;? /*<! Delay in milliseconds after this command */
} st7789_lcd_init_cmd_t;typedef struct {const st7789_lcd_init_cmd_t *init_cmds;???uint16_t init_cmds_size;??? /*<! Number of commands in above array */struct {unsigned int use_qspi_interface: 1;???? /*<! Set to 1 if use QSPI interface, default is SPI interface */} flags;
} st7789_vendor_config_t;static const st7789_lcd_init_cmd_t lcd_init_cmds [] ={/* {cmd, { data }, data_size, delay_ms} "*/// {0x2A, (uint8_t []){0x00, X_OFFSET, 0x00, 0xEF - X_OFFSET}, 4, 0}, // 列地址 0~171 (0xAB = 171)// {0x2B, (uint8_t []){0x00, Y_OFFSET, 0x01, 0x3F - Y_OFFSET}, 4, 0}, // 行地址 0~319{0x11, (uint8_t []){0x00}, 0, 0},{0x36, (uint8_t []){0x00}, 1, 0},{0x3A, (uint8_t []){0x05}, 1, 0},{0xB2, (uint8_t []){0x0C, 0x0C, 0x00, 0x33, 0x33}, 5, 0},{0xB7, (uint8_t []){0x35}, 1, 0},{0xBB, (uint8_t []){0x35}, 1, 0},{0xC0, (uint8_t []){0x2C}, 1, 0},{0xC2, (uint8_t []){0x01}, 1, 0},{0xC3, (uint8_t []){0x13}, 1, 0},{0xC4, (uint8_t []){0x20}, 1, 0},{0xC6, (uint8_t []){0x0F}, 1, 0},{0xD0, (uint8_t []){0xA4, 0xA1}, 2, 0},{0xD6, (uint8_t []){0xA1}, 1, 0},{0xE0, (uint8_t []){0xF0, 0x00, 0x04, 0x04, 0x04, 0x05, 0x29, 0x33, 0x3e, 0x38, 0x12, 0x12, 0x28, 0x30}, 14, 0},{0xE1, (uint8_t []){0xF0, 0x07, 0x0A, 0x0D, 0x0b, 0x07, 0x28, 0x33, 0x3e, 0x36, 0x14, 0x14, 0x29, 0x32}, 14, 0},{0x21, (uint8_t []){0x00}, 0, 0},{0x11, (uint8_t []){0x00}, 0, 120},{0x29, (uint8_t []){0x00}, 0, 0},
};// 設置液晶屏顏色
void lcd_set_color(uint16_t color)
{// 分配內存 這里分配了液晶屏一行數據需要的大小uint16_t *buffer = (uint16_t *)heap_caps_malloc(EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES * sizeof(uint16_t), MALLOC_CAP_8BIT | MALLOC_CAP_INTERNAL);if (NULL == buffer){ESP_LOGE(TAG, "Memory for bitmap is not enough");}else{for (size_t i = 0; i < EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES; i++) // 給緩存中放入顏色數據{buffer[i] = color;}esp_lcd_panel_draw_bitmap(panel_handle, 0 + X_OFFSET, 0, EXAMPLE_LCD_H_RES + X_OFFSET, EXAMPLE_LCD_V_RES, buffer);free(buffer); // 釋放內存}
}void app_main(void)
{// 關閉LCD背光ESP_LOGI(TAG, "Turn off LCD backlight");gpio_config_t bk_gpio_config = {.mode = GPIO_MODE_OUTPUT, // 設置GPIO模式為輸出.pin_bit_mask = 1ULL << EXAMPLE_PIN_NUM_BK_LIGHT // 設置背光控制引腳};ESP_ERROR_CHECK(gpio_config(&bk_gpio_config)); // 配置GPIO// 初始化SPI總線ESP_LOGI(TAG, "Initialize SPI bus");spi_bus_config_t buscfg = {.sclk_io_num = EXAMPLE_PIN_NUM_SCLK, // SCLK引腳編號.mosi_io_num = EXAMPLE_PIN_NUM_MOSI, // MOSI引腳編號.miso_io_num = GPIO_NUM_NC,????????? // MISO引腳編號.quadwp_io_num = GPIO_NUM_NC,??????? // QUADWP引腳編號（未使用）.quadhd_io_num = GPIO_NUM_NC,??????? // QUADHD引腳編號（未使用）.max_transfer_sz = EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES * sizeof(uint16_t), // 最大傳輸大小};ESP_ERROR_CHECK(spi_bus_initialize(LCD_HOST, &buscfg, SPI_DMA_CH_AUTO)); // 初始化SPI總線// 安裝面板IOESP_LOGI(TAG, "Install panel IO");esp_lcd_panel_io_handle_t io_handle = NULL;esp_lcd_panel_io_spi_config_t io_config = {.dc_gpio_num = EXAMPLE_PIN_NUM_LCD_DC, // 數據/命令控制引腳編號.cs_gpio_num = EXAMPLE_PIN_NUM_LCD_CS, // 片選引腳編號.pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ, // 像素時鐘頻率.lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS, // 命令位數.lcd_param_bits = EXAMPLE_LCD_PARAM_BITS, // 參數位數.spi_mode = 3, // SPI模式.trans_queue_depth = 10, // 傳輸隊列深度};// 將LCD連接到SPI總線ESP_ERROR_CHECK(esp_lcd_new_panel_io_spi((esp_lcd_spi_bus_handle_t)LCD_HOST, &io_config, &io_handle));st7789_vendor_config_t vendor_config = {? // 用于替換驅動組件中的初始化命令及參數.init_cmds = lcd_init_cmds,.init_cmds_size = sizeof(lcd_init_cmds) / sizeof(st7789_lcd_init_cmd_t),};esp_lcd_panel_dev_config_t panel_config = {.reset_gpio_num = EXAMPLE_PIN_NUM_LCD_RST,? // 復位引腳編號.rgb_ele_order = LCD_RGB_ELEMENT_ORDER_RGB, // RGB元素順序.bits_per_pixel = 16,?????????????????????? // 每像素位數.data_endian = LCD_RGB_DATA_ENDIAN_BIG,???? // MSB.vendor_config = &vendor_config,?????????? // 用于替換驅動組件中的初始化命令及參數};ESP_LOGI(TAG, "Install ST7789 panel driver");ESP_ERROR_CHECK(esp_lcd_new_panel_st7789(io_handle, &panel_config, &panel_handle));// 復位和初始化面板ESP_ERROR_CHECK(esp_lcd_panel_reset(panel_handle)); // 復位面板ESP_ERROR_CHECK(esp_lcd_panel_init(panel_handle)); // 初始化面板ESP_ERROR_CHECK(esp_lcd_panel_invert_color(panel_handle, true)); // 反轉顏色ESP_ERROR_CHECK(esp_lcd_panel_mirror(panel_handle, false, false)); // 鏡像顯示（水平鏡像）// 用戶可以在點亮屏幕或背光之前刷新預定義的圖案到屏幕上ESP_ERROR_CHECK(esp_lcd_panel_disp_on_off(panel_handle, true)); // 打開屏幕顯示// 打開LCD背光ESP_LOGI(TAG, "Turn on LCD backlight");gpio_set_level(EXAMPLE_PIN_NUM_BK_LIGHT, EXAMPLE_LCD_BK_LIGHT_ON_LEVEL); // 設置背光引腳電平while(1){lcd_set_color(0xFFFF);vTaskDelay(1000 / portTICK_PERIOD_MS);ESP_LOGI(TAG, "lcd_set_color switch");lcd_set_color(0x001F);vTaskDelay(1000 / portTICK_PERIOD_MS);ESP_LOGI(TAG, "lcd_set_color switch");}
}

如果編譯報錯fatal error: esp_lcd_panel_io.h: No such file or directory

需要在main/CMakeLists.txt中添加esp_lcd組件

idf_component_register(SRCS "main.c"PRIV_REQUIRES esp_lcdINCLUDE_DIRS "")