警告

This document is not updated for ESP32H21 yet, so some of the content may not be correct.

This warning was automatically inserted due to the source file being in the add_warnings_pages list.

# I2C 接口的 LCD

[English]

1. 创建 I2C 总线。详细信息，请参阅 I2C API 文档。

   >     i2c_master_bus_handle_t i2c_bus = NULL;
   >     i2c_master_bus_config_t bus_config = {
   >         .clk_source = I2C_CLK_SRC_DEFAULT,
   >         .glitch_ignore_cnt = 7,
   >         .i2c_port = I2C_BUS_PORT,
   >         .sda_io_num = EXAMPLE_PIN_NUM_SDA,
   >         .scl_io_num = EXAMPLE_PIN_NUM_SCL,
   >         .flags.enable_internal_pullup = true,
   >     };
   >     ESP_ERROR_CHECK(i2c_new_master_bus(&bus_config, &i2c_bus));

2. 从 I2C 总线分配一个 LCD IO 设备句柄。在此步骤中，需要提供以下信息：

   > - `esp_lcd_panel_io_i2c_config_t::dev_addr` 设置 LCD 控制器芯片的 I2C 设备地址。LCD 驱动程序使用此地址与 LCD 控制器芯片通信。

   > - `esp_lcd_panel_io_i2c_config_t::scl_speed_hz` 设置 I2C 时钟频率 (Hz)。该值不应超过 LCD 规格书中推荐的范围。

   > - `esp_lcd_panel_io_i2c_config_t::lcd_cmd_bits` 和 `esp_lcd_panel_io_i2c_config_t::lcd_param_bits` 分别设置 LCD 控制器芯片可识别的命令及参数的位宽。不同芯片对位宽要求不同，请提前参阅 LCD 规格书。

   >     esp_lcd_panel_io_handle_t io_handle = NULL;
   >     esp_lcd_panel_io_i2c_config_t io_config = {
   >         .dev_addr = EXAMPLE_I2C_HW_ADDR,
   >         .scl_speed_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ,
   >         .control_phase_bytes = 1, // 参阅 LCD 规格
   >         .dc_bit_offset = 6,       // 参阅 LCD 规格
   >         .lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS,
   >         .lcd_param_bits = EXAMPLE_LCD_CMD_BITS,
   >     };
   >     ESP_ERROR_CHECK(esp_lcd_new_panel_io_i2c(i2c_bus, &io_config, &io_handle));

3. 安装 LCD 控制器驱动程序。LCD 控制器驱动程序负责向 LCD 控制器芯片发送命令和参数。在此步骤中，需要指定上一步骤中分配到的 I2C IO 设备句柄以及一些面板特定配置：

   > - `esp_lcd_panel_dev_config_t::reset_gpio_num` 设置 LCD 的硬件复位 GPIO 编号。如果 LCD 没有硬件复位管脚，则将此设置为 `-1`。

   > - `esp_lcd_panel_dev_config_t::bits_per_pixel` 设置像素颜色数据的位宽。LCD 驱动程序使用此值计算要发送到 LCD 控制器芯片的字节数。

   >     esp_lcd_panel_handle_t panel_handle = NULL;
   >     esp_lcd_panel_dev_config_t panel_config = {
   >         .bits_per_pixel = 1,
   >         .reset_gpio_num = EXAMPLE_PIN_NUM_RST,
   >     };
   >     ESP_ERROR_CHECK(esp_lcd_new_panel_ssd1306(io_handle, &panel_config, &panel_handle));

# API 参考

## Header File

- components/esp_lcd/include/esp_lcd_io_i2c.h

- This header file can be included with:

  >     #include "esp_lcd_io_i2c.h"

- This header file is a part of the API provided by the `esp_lcd` component. To declare that your component depends on `esp_lcd`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_lcd

  > or

  >     PRIV_REQUIRES esp_lcd

## Functions

esp_err_t esp_lcd_new_panel_io_i2c_v1(uint32_t bus, const esp_lcd_panel_io_i2c_config_t *io_config, esp_lcd_panel_io_handle_t *ret_io)

  Create LCD panel IO handle, for I2C interface in legacy implementation.

  备注

  Please don't call this function in your project directly. Please call `esp_lcd_new_panel_to_i2c` instead.

  参数:

    - bus -- [in] I2C bus handle, (in uint32_t)

    - io_config -- [in] IO configuration, for I2C interface

    - ret_io -- [out] Returned IO handle

  返回:

    - ESP_ERR_INVALID_ARG if parameter is invalid

    - ESP_ERR_NO_MEM if out of memory

    - ESP_OK on success

esp_err_t esp_lcd_new_panel_io_i2c_v2(i2c_master_bus_handle_t bus, const esp_lcd_panel_io_i2c_config_t *io_config, esp_lcd_panel_io_handle_t *ret_io)

  Create LCD panel IO handle, for I2C interface in new implementation.

  备注

  Please don't call this function in your project directly. Please call `esp_lcd_new_panel_to_i2c` instead.

  参数:

    - bus -- [in] I2C bus handle, (in i2c_master_dev_handle_t)

    - io_config -- [in] IO configuration, for I2C interface

    - ret_io -- [out] Returned IO handle

  返回:

    - ESP_ERR_INVALID_ARG if parameter is invalid

    - ESP_ERR_NO_MEM if out of memory

    - ESP_OK on success

## Structures

struct esp_lcd_panel_io_i2c_config_t

  Panel IO configuration structure, for I2C interface.

  Public Members

  uint32_t dev_addr

    I2C device address

  esp_lcd_panel_io_color_trans_done_cb_t on_color_trans_done

    Callback invoked when color data transfer has finished

  void *user_ctx

    User private data, passed directly to on_color_trans_done's user_ctx

  size_t control_phase_bytes

    I2C LCD panel will encode control information (e.g. D/C selection) into control phase, in several bytes

  unsigned int dc_bit_offset

    Offset of the D/C selection bit in control phase

  int lcd_cmd_bits

    Bit-width of LCD command

  int lcd_param_bits

    Bit-width of LCD parameter

  unsigned int dc_low_on_data

    If this flag is enabled, DC line = 0 means transfer data, DC line = 1 means transfer command; vice versa

  unsigned int disable_control_phase

    If this flag is enabled, the control phase isn't used

  struct esp_lcd_panel_io_i2c_config_t flags

    Extra flags to fine-tune the I2C device

  uint32_t scl_speed_hz

    I2C LCD SCL frequency (hz)

## Macros

esp_lcd_new_panel_io_i2c(bus, io_config, ret_io)

  Create LCD panel IO handle.

  参数:

    - bus -- [in] I2C bus handle

    - io_config -- [in] IO configuration, for I2C interface

    - ret_io -- [out] Returned IO handle

  返回:

    - ESP_ERR_INVALID_ARG if parameter is invalid

    - ESP_ERR_NO_MEM if out of memory

    - ESP_OK on success

## Type Definitions

typedef uint32_t esp_lcd_i2c_bus_handle_t

  Type of LCD I2C bus handle

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