I80 接口的 LCD
调用
esp_lcd_new_i80_bus()
创建 I80 总线。请为英特尔 8080 并行总线设置以下参数:esp_lcd_i80_bus_config_t::clk_src
设置 I80 总线的时钟源。请注意,不同的 ESP 芯片可能有不同的默认时钟源。esp_lcd_i80_bus_config_t::wr_gpio_num
设置像素时钟的 GPIO 编号(在某些 LCD 规格书中也被称为WR
)esp_lcd_i80_bus_config_t::dc_gpio_num
设置数据或命令选择管脚的 GPIO 编号(在某些 LCD 规格书中也被称为RS
)esp_lcd_i80_bus_config_t::bus_width
设置数据总线的位宽(仅支持8
位或16
位)esp_lcd_i80_bus_config_t::data_gpio_nums
是数据总线的 GPIO 编号数组。GPIO 的数量应与esp_lcd_i80_bus_config_t::bus_width
的值等同。esp_lcd_i80_bus_config_t::max_transfer_bytes
设置单次传输的最大字节数。
esp_lcd_i80_bus_handle_t i80_bus = NULL; esp_lcd_i80_bus_config_t bus_config = { .clk_src = LCD_CLK_SRC_DEFAULT, .dc_gpio_num = EXAMPLE_PIN_NUM_DC, .wr_gpio_num = EXAMPLE_PIN_NUM_PCLK, .data_gpio_nums = { EXAMPLE_PIN_NUM_DATA0, EXAMPLE_PIN_NUM_DATA1, EXAMPLE_PIN_NUM_DATA2, EXAMPLE_PIN_NUM_DATA3, EXAMPLE_PIN_NUM_DATA4, EXAMPLE_PIN_NUM_DATA5, EXAMPLE_PIN_NUM_DATA6, EXAMPLE_PIN_NUM_DATA7, }, .bus_width = 8, .max_transfer_bytes = EXAMPLE_LCD_H_RES * 100 * sizeof(uint16_t), // 单次最多可传输 100 行像素(假设像素格式为 RGB565) .dma_burst_size = EXAMPLE_DMA_BURST_SIZE, }; ESP_ERROR_CHECK(esp_lcd_new_i80_bus(&bus_config, &i80_bus));
从 I80 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_i80_config_t::cs_gpio_num
设置片选管脚的 GPIO 编号。esp_lcd_panel_io_i80_config_t::pclk_hz
设置像素时钟频率 (Hz)。像素时钟频率越高,刷新率越高,但如果 DMA 带宽不足或 LCD 控制器芯片不支持高像素时钟频率,则可能会导致闪烁。esp_lcd_panel_io_i80_config_t::lcd_cmd_bits
和esp_lcd_panel_io_i80_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_i80_config_t::trans_queue_depth
设置在 LCD IO 设备中可以排队的最大传输量。该值越大,可以排队的传输越多,但消耗的内存也越多。
esp_lcd_panel_io_handle_t io_handle = NULL; esp_lcd_panel_io_i80_config_t io_config = { .cs_gpio_num = EXAMPLE_PIN_NUM_CS, .pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ, .trans_queue_depth = 10, .dc_levels = { .dc_idle_level = 0, .dc_cmd_level = 0, .dc_dummy_level = 0, .dc_data_level = 1, }, .lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS, .lcd_param_bits = EXAMPLE_LCD_PARAM_BITS, }; ESP_ERROR_CHECK(esp_lcd_new_panel_io_i80(i80_bus, &io_config, &io_handle));
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 I80 IO 设备句柄以及一些面板特定配置:
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_dev_config_t::reset_gpio_num
设置复位管脚的 GPIO 编号。如果 LCD 控制器芯片没有复位管脚,可将此值设置为-1
。esp_lcd_panel_dev_config_t::rgb_ele_order
设置像素颜色数据的颜色顺序。
esp_lcd_panel_dev_config_t panel_config = { .reset_gpio_num = EXAMPLE_PIN_NUM_RST, .rgb_ele_order = LCD_RGB_ELEMENT_ORDER_RGB, .bits_per_pixel = 16, }; ESP_ERROR_CHECK(esp_lcd_new_panel_st7789(io_handle, &panel_config, &panel_handle));
API 参考
Header File
This header file can be included with:
#include "esp_lcd_io_i80.h"
This header file is a part of the API provided by the
esp_lcd
component. To declare that your component depends onesp_lcd
, add the following to your CMakeLists.txt:REQUIRES esp_lcd
or
PRIV_REQUIRES esp_lcd
Functions
-
esp_err_t esp_lcd_new_i80_bus(const esp_lcd_i80_bus_config_t *bus_config, esp_lcd_i80_bus_handle_t *ret_bus)
Create Intel 8080 bus handle.
- 参数
bus_config -- [in] Bus configuration
ret_bus -- [out] Returned bus handle
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_ERR_NO_MEM if out of memory
ESP_ERR_NOT_FOUND if no free bus is available
ESP_OK on success
-
esp_err_t esp_lcd_del_i80_bus(esp_lcd_i80_bus_handle_t bus)
Destroy Intel 8080 bus handle.
- 参数
bus -- [in] Intel 8080 bus handle, created by
esp_lcd_new_i80_bus()
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_ERR_INVALID_STATE if there still be some device attached to the bus
ESP_OK on success
-
esp_err_t esp_lcd_new_panel_io_i80(esp_lcd_i80_bus_handle_t bus, const esp_lcd_panel_io_i80_config_t *io_config, esp_lcd_panel_io_handle_t *ret_io)
Create LCD panel IO, for Intel 8080 interface.
- 参数
bus -- [in] Intel 8080 bus handle, created by
esp_lcd_new_i80_bus()
io_config -- [in] IO configuration, for i80 interface
ret_io -- [out] Returned panel IO handle
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_ERR_NOT_SUPPORTED if some configuration can't be satisfied, e.g. pixel clock out of the range
ESP_ERR_NO_MEM if out of memory
ESP_OK on success
-
void *esp_lcd_i80_alloc_draw_buffer(esp_lcd_panel_io_handle_t io, size_t size, uint32_t caps)
Allocate a draw buffer that can be used by I80 interfaced LCD panel.
备注
This function differs from the normal 'heap_caps_*' functions in that it can also automatically handle the alignment required by DMA burst, cache line size, etc.
- 参数
io -- [in] Panel IO handle, created by
esp_lcd_new_panel_io_i80()
size -- [in] Size of memory to be allocated
caps -- [in] Bitwise OR of MALLOC_CAP_* flags indicating the type of memory desired for the allocation
- 返回
Pointer to a new buffer of size 'size' with capabilities 'caps', or NULL if allocation failed
Structures
-
struct esp_lcd_i80_bus_config_t
LCD Intel 8080 bus configuration structure.
Public Members
-
int dc_gpio_num
GPIO used for D/C line
-
int wr_gpio_num
GPIO used for WR line
-
lcd_clock_source_t clk_src
Clock source for the I80 LCD peripheral
-
int data_gpio_nums[ESP_LCD_I80_BUS_WIDTH_MAX]
GPIOs used for data lines
-
size_t bus_width
Number of data lines, 8 or 16
-
size_t max_transfer_bytes
Maximum transfer size, this determines the length of internal DMA link
-
size_t psram_trans_align
DMA transfer alignment for data allocated from PSRAM
-
size_t dma_burst_size
DMA burst size, in bytes
-
size_t sram_trans_align
DMA transfer alignment for data allocated from SRAM
-
int dc_gpio_num
-
struct esp_lcd_panel_io_i80_config_t
Panel IO configuration structure, for intel 8080 interface.
Public Members
-
int cs_gpio_num
GPIO used for CS line, set to -1 will declaim exclusively use of I80 bus
-
uint32_t pclk_hz
Frequency of pixel clock
-
size_t trans_queue_depth
Transaction queue size, larger queue, higher throughput
-
esp_lcd_panel_io_color_trans_done_cb_t on_color_trans_done
Callback invoked when color data was transferred done
-
void *user_ctx
User private data, passed directly to on_color_trans_done's user_ctx
-
int lcd_cmd_bits
Bit-width of LCD command
-
int lcd_param_bits
Bit-width of LCD parameter
-
unsigned int dc_idle_level
Level of DC line in IDLE phase
-
unsigned int dc_cmd_level
Level of DC line in CMD phase
-
unsigned int dc_dummy_level
Level of DC line in DUMMY phase
-
unsigned int dc_data_level
Level of DC line in DATA phase
-
struct esp_lcd_panel_io_i80_config_t::[anonymous] dc_levels
Each i80 device might have its own D/C control logic
-
unsigned int cs_active_high
If set, a high level of CS line will select the device, otherwise, CS line is low level active
-
unsigned int reverse_color_bits
Reverse the data bits, D[N:0] -> D[0:N]
-
unsigned int swap_color_bytes
Swap adjacent two color bytes
-
unsigned int pclk_active_neg
The display will write data lines when there's a falling edge on WR signal (a.k.a the PCLK)
-
unsigned int pclk_idle_low
The WR signal (a.k.a the PCLK) stays at low level in IDLE phase
-
struct esp_lcd_panel_io_i80_config_t::[anonymous] flags
Panel IO config flags
-
int cs_gpio_num
Macros
-
ESP_LCD_I80_BUS_WIDTH_MAX
Maximum width of I80 bus
Type Definitions
-
typedef struct esp_lcd_i80_bus_t *esp_lcd_i80_bus_handle_t
Type of LCD intel 8080 bus handle