SOC-ESP32S3部分：31-ESP-LCD控制器库
飞书文档
https://x509p6c8to.feishu.cn/wiki/Syy3wsqHLiIiQJkC6PucEJ7Snib
ESP 系列芯片可以支持市场上常见的 LCD（如 SPI LCD、I2C LCD、并行 LCD (Intel 8080)、RGB/SRGB LCD、MIPI DSI LCD 等）所需的各种时序。esp_lcd 控制器为上述各类 LCD 提供了一个统一的抽象驱动框架。
更多支持的接口例程可以查看：esp-idf/examples/peripherals/lcd
在开发LCD类应用时，我们可以优先选择IDF自带了部分驱动，例如NT35510 SSD1306 ST7789，这部分驱动位于esp-idf/components/esp_lcd中，或者，我们也可以在组件库中查找，例如gc9a01
https://components.espressif.com/components?q=esp_lcd_gc9a01这些驱动都是适配了esp_lcd控制器的，使用起来非常方便。
如果以上两个方法都找不到对应驱动呢？这时候就需要我们自己写了，有两种办法，
第一种是比较传统的，是把厂家提供的驱动文件，修改为ESP32的接口，例如SPI、IO相关的函数，这部分可以参考我们SPI课程中，使用SPI适配的ST7789屏幕驱动。
第二种是推荐大家用的，把驱动按esp_lcd框架的方式封装，找接近的芯片，更改部分参数即可，例如找不到ST7789的，我们可以找ST77916的，一般同一个厂家一系列的芯片，差异点只在初始化参数的不同。
https://components.espressif.com/components?q=esp_lcd_st最终参考esp-idf/examples/peripherals/lcd/spi_lcd_touch实现的驱动：
步骤如下
- 初始化背光IO
- 初始化LCD的SPI配置
- 初始化其它显示IO
- 初始化ST7789驱动
- 设置屏幕显示方向颜色，打开背光
- 使用绘制函数绘制图像esp_lcd_panel_draw_bitmap
初始化背光IO
gpio_config_t bk_gpio_config = {.mode = GPIO_MODE_OUTPUT, // 设置GPIO模式为输出.pin_bit_mask = 1ULL << EXAMPLE_PIN_NUM_BK_LIGHT // 设置背光控制引脚};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引脚编号.mosi_io_num = EXAMPLE_PIN_NUM_MOSI, // MOSI引脚编号.miso_io_num = GPIO_NUM_NC, // MISO引脚编号.quadwp_io_num = GPIO_NUM_NC, // QUADWP引脚编号（未使用）.quadhd_io_num = GPIO_NUM_NC, // QUADHD引脚编号（未使用）.max_transfer_sz = EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES * sizeof(uint16_t), // 最大传输大小};ESP_ERROR_CHECK(spi_bus_initialize(LCD_HOST, &buscfg, SPI_DMA_CH_AUTO)); // 初始化SPI总线初始化其它显示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, // 数据/命令控制引脚编号.cs_gpio_num = EXAMPLE_PIN_NUM_LCD_CS, // 片选引脚编号.pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ, // 像素时钟频率.lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS, // 命令位数.lcd_param_bits = EXAMPLE_LCD_PARAM_BITS, // 参数位数.spi_mode = 3, // SPI模式.trans_queue_depth = 10, // 传输队列深度};// 将LCD连接到SPI总线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驱动
// 安装st7789面板驱动esp_lcd_panel_handle_t panel_handle = NULL;esp_lcd_panel_dev_config_t panel_config = {.reset_gpio_num = EXAMPLE_PIN_NUM_LCD_RST, // 复位引脚编号.rgb_ele_order = LCD_RGB_ELEMENT_ORDER_RGB, // RGB元素顺序.bits_per_pixel = 16, // 每像素位数.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));设置屏幕显示方向颜色，打开背光
// 复位和初始化面板ESP_ERROR_CHECK(esp_lcd_panel_reset(panel_handle)); // 复位面板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)); // 反转颜色ESP_ERROR_CHECK(esp_lcd_panel_mirror(panel_handle, true, false)); // 镜像显示（水平镜像）// 用户可以在点亮屏幕或背光之前刷新预定义的图案到屏幕上ESP_ERROR_CHECK(esp_lcd_panel_disp_on_off(panel_handle, true)); // 打开屏幕显示// 打开LCD背光ESP_LOGI(TAG, "Turn on LCD backlight");gpio_set_level(EXAMPLE_PIN_NUM_BK_LIGHT, EXAMPLE_LCD_BK_LIGHT_ON_LEVEL); // 设置背光引脚电平使用绘制函数绘制图像esp_lcd_panel_draw_bitmap
// 设置液晶屏颜色
void lcd_set_color(uint16_t color)
{// 分配内存 这里分配了液晶屏一行数据需要的大小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++) // 给缓存中放入颜色数据{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); // 释放内存}
}SPI屏幕
SPI屏幕使用的驱动芯片是ST7789，这个驱动芯片支持的分辨率是240*320，据厂家手册说明可知，由于是异形屏幕，屏幕的分辨率是172*320，所以驱动芯片左右两边分别有34列((240-172)/2) = 34是没有接到屏幕的，所以我们设置显示地址是，要偏移34列，屏幕接线部分如下：
|
|
|
从原理图可知：
SPI SCLK为GPIO_NUM_16
SPI MOSI为GPIO_NUM_17
SPI MISO不需要
LCD_DC为GPIO_NUM_21
LCD_RST为GPIO_NUM_18
LCD_CS为GPIO_NUM_15
背光IO为GPIO_NUM_2，背光有效电平为低电平具体代码如下
#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（假设X起始偏移为0，Y起始偏移为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},
};// 设置液晶屏颜色
void lcd_set_color(uint16_t color)
{// 分配内存 这里分配了液晶屏一行数据需要的大小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++) // 给缓存中放入颜色数据{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); // 释放内存}
}void app_main(void)
{// 关闭LCD背光ESP_LOGI(TAG, "Turn off LCD backlight");gpio_config_t bk_gpio_config = {.mode = GPIO_MODE_OUTPUT, // 设置GPIO模式为输出.pin_bit_mask = 1ULL << EXAMPLE_PIN_NUM_BK_LIGHT // 设置背光控制引脚};ESP_ERROR_CHECK(gpio_config(&bk_gpio_config)); // 配置GPIO// 初始化SPI总线ESP_LOGI(TAG, "Initialize SPI bus");spi_bus_config_t buscfg = {.sclk_io_num = EXAMPLE_PIN_NUM_SCLK, // SCLK引脚编号.mosi_io_num = EXAMPLE_PIN_NUM_MOSI, // MOSI引脚编号.miso_io_num = GPIO_NUM_NC, // MISO引脚编号.quadwp_io_num = GPIO_NUM_NC, // QUADWP引脚编号（未使用）.quadhd_io_num = GPIO_NUM_NC, // QUADHD引脚编号（未使用）.max_transfer_sz = EXAMPLE_LCD_H_RES * EXAMPLE_LCD_V_RES * sizeof(uint16_t), // 最大传输大小};ESP_ERROR_CHECK(spi_bus_initialize(LCD_HOST, &buscfg, SPI_DMA_CH_AUTO)); // 初始化SPI总线// 安装面板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, // 数据/命令控制引脚编号.cs_gpio_num = EXAMPLE_PIN_NUM_LCD_CS, // 片选引脚编号.pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ, // 像素时钟频率.lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS, // 命令位数.lcd_param_bits = EXAMPLE_LCD_PARAM_BITS, // 参数位数.spi_mode = 3, // SPI模式.trans_queue_depth = 10, // 传输队列深度};// 将LCD连接到SPI总线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 = { // 用于替换驱动组件中的初始化命令及参数.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, // 复位引脚编号.rgb_ele_order = LCD_RGB_ELEMENT_ORDER_RGB, // RGB元素顺序.bits_per_pixel = 16, // 每像素位数.data_endian = LCD_RGB_DATA_ENDIAN_BIG, // MSB.vendor_config = &vendor_config, // 用于替换驱动组件中的初始化命令及参数};ESP_LOGI(TAG, "Install ST7789 panel driver");ESP_ERROR_CHECK(esp_lcd_new_panel_st7789(io_handle, &panel_config, &panel_handle));// 复位和初始化面板ESP_ERROR_CHECK(esp_lcd_panel_reset(panel_handle)); // 复位面板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)); // 反转颜色ESP_ERROR_CHECK(esp_lcd_panel_mirror(panel_handle, false, false)); // 镜像显示（水平镜像）// 用户可以在点亮屏幕或背光之前刷新预定义的图案到屏幕上ESP_ERROR_CHECK(esp_lcd_panel_disp_on_off(panel_handle, true)); // 打开屏幕显示// 打开LCD背光ESP_LOGI(TAG, "Turn on LCD backlight");gpio_set_level(EXAMPLE_PIN_NUM_BK_LIGHT, EXAMPLE_LCD_BK_LIGHT_ON_LEVEL); // 设置背光引脚电平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");}
}如果编译报错fatal error: esp_lcd_panel_io.h: No such file or directory
需要在main/CMakeLists.txt中添加esp_lcd组件
idf_component_register(SRCS "main.c"PRIV_REQUIRES esp_lcdINCLUDE_DIRS "")