RGB Interfaced LCD

[中文]

RGB LCD panel is created by esp_lcd_new_rgb_panel(), with various configurations specified in esp_lcd_rgb_panel_config_t.

RGB LCD Frame Buffer Operation Modes

Most of the time, the RGB LCD driver should maintain at least one screen sized frame buffer. According to the number and location of the frame buffer, the driver provides several different buffer modes.

Single Frame Buffer in Internal Memory

This is the default and simplest and you do not have to specify flags or bounce buffer options. A frame buffer is allocated from the internal memory. The frame data is read out by DMA to the LCD verbatim. It needs no CPU intervention to function, but it has the downside that it uses up a fair bit of the limited amount of internal memory.

esp_lcd_panel_handle_t panel_handle = NULL;
esp_lcd_rgb_panel_config_t panel_config = {
    .data_width = 16, // RGB565 in parallel mode, thus 16 bits in width
    .clk_src = LCD_CLK_SRC_DEFAULT,
    .disp_gpio_num = EXAMPLE_PIN_NUM_DISP_EN,
    .pclk_gpio_num = EXAMPLE_PIN_NUM_PCLK,
    .vsync_gpio_num = EXAMPLE_PIN_NUM_VSYNC,
    .hsync_gpio_num = EXAMPLE_PIN_NUM_HSYNC,
    .de_gpio_num = EXAMPLE_PIN_NUM_DE,
    .data_gpio_nums = {
        EXAMPLE_PIN_NUM_DATA0,
        EXAMPLE_PIN_NUM_DATA1,
        EXAMPLE_PIN_NUM_DATA2,
        // other GPIOs
        // The number of GPIOs here should be the same to the value of "data_width" above
        ...
    },
    // The timing parameters should refer to your LCD spec
    .timings = {
        .pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ,
        .h_res = EXAMPLE_LCD_H_RES,
        .v_res = EXAMPLE_LCD_V_RES,
        .hsync_back_porch = 40,
        .hsync_front_porch = 20,
        .hsync_pulse_width = 1,
        .vsync_back_porch = 8,
        .vsync_front_porch = 4,
        .vsync_pulse_width = 1,
    },
};
ESP_ERROR_CHECK(esp_lcd_new_rgb_panel(&panel_config, &panel_handle));

Single Frame Buffer in PSRAM

If you have PSRAM and prefer to store the frame buffer there instead of using the limited internal memory, the LCD peripheral can utilize EDMA to fetch frame data directly from PSRAM, bypassing the internal cache. This can be enabled by setting esp_lcd_rgb_panel_config_t::fb_in_psram to true. The trade-off is that when both the CPU and EDMA need access to PSRAM, the bandwidth is shared between them, meaning EDMA and the CPU each get half. If other peripherals are also using EDMA, a high pixel clock might cause LCD peripheral starvation, leading to display corruption. However, with a sufficiently low pixel clock, this approach minimizes CPU intervention.

The PSRAM shares the same SPI bus with the main flash (the one stores your firmware binary). At any given time, there can only be one consumer of the SPI bus. When you also use the main flash to serve your file system (e.g., SPIFFS), the bandwidth of the underlying SPI bus will also be shared, leading to display corruption. You can use esp_lcd_rgb_panel_set_pclk() to update the pixel clock frequency to a lower value.

esp_lcd_panel_handle_t panel_handle = NULL;
esp_lcd_rgb_panel_config_t panel_config = {
    .data_width = 16, // RGB565 in parallel mode, thus 16 bits in width
    .clk_src = LCD_CLK_SRC_DEFAULT,
    .disp_gpio_num = EXAMPLE_PIN_NUM_DISP_EN,
    .pclk_gpio_num = EXAMPLE_PIN_NUM_PCLK,
    .vsync_gpio_num = EXAMPLE_PIN_NUM_VSYNC,
    .hsync_gpio_num = EXAMPLE_PIN_NUM_HSYNC,
    .de_gpio_num = EXAMPLE_PIN_NUM_DE,
    .data_gpio_nums = {
        EXAMPLE_PIN_NUM_DATA0,
        EXAMPLE_PIN_NUM_DATA1,
        EXAMPLE_PIN_NUM_DATA2,
        // other GPIOs
        // The number of GPIOs here should be the same to the value of "data_width" above
        ...
    },
    // The timing parameters should refer to your LCD spec
    .timings = {
        .pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ,
        .h_res = EXAMPLE_LCD_H_RES,
        .v_res = EXAMPLE_LCD_V_RES,
        .hsync_back_porch = 40,
        .hsync_front_porch = 20,
        .hsync_pulse_width = 1,
        .vsync_back_porch = 8,
        .vsync_front_porch = 4,
        .vsync_pulse_width = 1,
    },
    .flags.fb_in_psram = true, // allocate frame buffer from PSRAM
};
ESP_ERROR_CHECK(esp_lcd_new_rgb_panel(&panel_config, &panel_handle));

Double Frame Buffer in PSRAM

To prevent tearing effects, the simplest method is to use two screen-sized frame buffers. Given the limited internal memory, these buffers must be allocated from PSRAM. This ensures that the frame buffer being written to by the CPU and the one being read by the EDMA are always distinct and independent. The EDMA will only switch between the two buffers once the current write operation is complete and the frame has been fully transmitted to the LCD. The main drawback of this approach is the need to maintain synchronization between the two frame buffers.

esp_lcd_panel_handle_t panel_handle = NULL;
esp_lcd_rgb_panel_config_t panel_config = {
    .data_width = 16, // RGB565 in parallel mode, thus 16 bits in width
    .num_fbs = 2,     // allocate double frame buffer
    .clk_src = LCD_CLK_SRC_DEFAULT,
    .disp_gpio_num = EXAMPLE_PIN_NUM_DISP_EN,
    .pclk_gpio_num = EXAMPLE_PIN_NUM_PCLK,
    .vsync_gpio_num = EXAMPLE_PIN_NUM_VSYNC,
    .hsync_gpio_num = EXAMPLE_PIN_NUM_HSYNC,
    .de_gpio_num = EXAMPLE_PIN_NUM_DE,
    .data_gpio_nums = {
        EXAMPLE_PIN_NUM_DATA0,
        EXAMPLE_PIN_NUM_DATA1,
        EXAMPLE_PIN_NUM_DATA2,
        // other GPIOs
        // The number of GPIOs here should be the same to the value of "data_width" above
        ...
    },
    // The timing parameters should refer to your LCD spec
    .timings = {
        .pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ,
        .h_res = EXAMPLE_LCD_H_RES,
        .v_res = EXAMPLE_LCD_V_RES,
        .hsync_back_porch = 40,
        .hsync_front_porch = 20,
        .hsync_pulse_width = 1,
        .vsync_back_porch = 8,
        .vsync_front_porch = 4,
        .vsync_pulse_width = 1,
    },
    .flags.fb_in_psram = true, // allocate frame buffer from PSRAM
};
ESP_ERROR_CHECK(esp_lcd_new_rgb_panel(&panel_config, &panel_handle));

Bounce Buffer with Single PSRAM Frame Buffer

This mode allocates two "bounce buffers" from internal memory and a main frame buffer in PSRAM. To enable this mode, set the esp_lcd_rgb_panel_config_t::fb_in_psram flag and specify a non-zero value for esp_lcd_rgb_panel_config_t::bounce_buffer_size_px. The bounce buffers only need to hold a few lines of display data, which is much smaller than the main frame buffer. The LCD peripheral uses DMA to read data from one bounce buffer while an interrupt routine uses the CPU DCache to copy data from the main PSRAM frame buffer into the other bounce buffer. Once the LCD peripheral finishes reading from the bounce buffer, the buffers swap roles, allowing the CPU to fill the other one. The advantage of this mode is achieving a higher pixel clock frequency. Since the bounce buffers are larger than the FIFOs in the EDMA path, this method is also more robust against short bandwidth spikes. The downside is a significant increase in CPU usage, and the LCD CANNOT function if the external memory cache is disabled, such as during OTA or NVS writes to the main flash.

Note

For optimal performance in this mode, it is highly recommended to enable the "PSRAM XIP (Execute In Place)" feature by turning on the Kconfig option: CONFIG_SPIRAM_XIP_FROM_PSRAM. This allows the CPU to fetch instructions and read-only data directly from PSRAM instead of the main flash. Additionally, the external memory cache remains active even when writing to the main flash via SPI 1, making it feasible to display an OTA progress bar during your application updates.

Note

This mode also faces issues due to limited PSRAM bandwidth. For instance, if your draw buffers are in PSRAM and their contents are copied to the internal frame buffer by CPU Core 1, while CPU Core 0 is performing another memory copy in the DMA EOF ISR, both CPUs will be accessing PSRAM via cache, sharing its bandwidth. This significantly increases the memory copy time in the DMA EOF ISR, causing the driver to fail in switching the bounce buffer promptly, resulting in a screen shift. Although the driver can detect this condition and restart in the LCD's VSYNC interrupt handler, you may still notice flickering on the screen.

esp_lcd_panel_handle_t panel_handle = NULL;
esp_lcd_rgb_panel_config_t panel_config = {
    .data_width = 16, // RGB565 in parallel mode, thus 16 bits in width
    .clk_src = LCD_CLK_SRC_DEFAULT,
    .bounce_buffer_size_px = 10 * EXAMPLE_LCD_H_RES, // allocate 10 lines data as bounce buffer from internal memory
    .disp_gpio_num = EXAMPLE_PIN_NUM_DISP_EN,
    .pclk_gpio_num = EXAMPLE_PIN_NUM_PCLK,
    .vsync_gpio_num = EXAMPLE_PIN_NUM_VSYNC,
    .hsync_gpio_num = EXAMPLE_PIN_NUM_HSYNC,
    .de_gpio_num = EXAMPLE_PIN_NUM_DE,
    .data_gpio_nums = {
        EXAMPLE_PIN_NUM_DATA0,
        EXAMPLE_PIN_NUM_DATA1,
        EXAMPLE_PIN_NUM_DATA2,
        // other GPIOs
        // The number of GPIOs here should be the same to the value of "data_width" above
        ...
    },
    // The timing parameters should refer to your LCD spec
    .timings = {
        .pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ,
        .h_res = EXAMPLE_LCD_H_RES,
        .v_res = EXAMPLE_LCD_V_RES,
        .hsync_back_porch = 40,
        .hsync_front_porch = 20,
        .hsync_pulse_width = 1,
        .vsync_back_porch = 8,
        .vsync_front_porch = 4,
        .vsync_pulse_width = 1,
    },
    .flags.fb_in_psram = true, // allocate frame buffer from PSRAM
};
ESP_ERROR_CHECK(esp_lcd_new_rgb_panel(&panel_config, &panel_handle));

Bounce Buffer Only

This mode is similar to Bounce Buffer with Single PSRAM Frame Buffer, but there is no PSRAM frame buffer initialized by the LCD driver. Instead, the user supplies a callback function that is responsible for filling the bounce buffers. As this driver does not care where the written pixels come from, this allows for the callback doing e.g., on-the-fly conversion from a smaller, 8-bit-per-pixel PSRAM frame buffer to a 16-bit LCD, or even procedurally generated frame-buffer-less graphics. This option is selected by setting the esp_lcd_rgb_panel_config_t::no_fb flag and supplying a esp_lcd_rgb_panel_config_t::bounce_buffer_size_px value. And then register the esp_lcd_rgb_panel_event_callbacks_t::on_bounce_empty callback by calling esp_lcd_rgb_panel_register_event_callbacks().

Note

In a well-designed embedded application, situations where the DMA cannot deliver data as fast as the LCD consumes it should be avoided. However, such scenarios can theoretically occur. In the ESP32-S3 hardware, this results in the LCD outputting dummy bytes while the DMA waits for data. If the DMA were to run in a continuous stream, it could cause a desynchronization between the LCD address from which the DMA reads data and the address from which the LCD peripheral outputs data, leading to a permanently shifted image. To prevent this, you can either enable the CONFIG_LCD_RGB_RESTART_IN_VSYNC option, allowing the driver to automatically restart the DMA during the VBlank interrupt, or call esp_lcd_rgb_panel_restart() to manually restart the DMA. Note that esp_lcd_rgb_panel_restart() does not restart the DMA immediately; instead, the DMA will be restarted at the next VSYNC event.

API Reference

Header File

  • components/esp_lcd/rgb/include/esp_lcd_panel_rgb.h

  • This header file can be included with:

    #include "esp_lcd_panel_rgb.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_rgb_panel(const esp_lcd_rgb_panel_config_t *rgb_panel_config, esp_lcd_panel_handle_t *ret_panel)

Create RGB LCD panel.

Parameters

  • rgb_panel_config -- [in] RGB panel configuration

  • ret_panel -- [out] Returned LCD panel handle

Returns

  • ESP_ERR_INVALID_ARG: Create RGB LCD panel failed because of invalid argument

  • ESP_ERR_NO_MEM: Create RGB LCD panel failed because of out of memory

  • ESP_ERR_NOT_FOUND: Create RGB LCD panel failed because some mandatory hardware resources are not found

  • ESP_OK: Create RGB LCD panel successfully

esp_err_t esp_lcd_rgb_panel_register_event_callbacks(esp_lcd_panel_handle_t panel, const esp_lcd_rgb_panel_event_callbacks_t *callbacks, void *user_ctx)

Register LCD RGB panel event callbacks.

Parameters

  • panel -- [in] LCD panel handle, returned from esp_lcd_new_rgb_panel

  • callbacks -- [in] Group of callback functions

  • user_ctx -- [in] User data, which will be passed to the callback functions directly

Returns

  • ESP_OK: Set event callbacks successfully

  • ESP_ERR_INVALID_ARG: Set event callbacks failed because of invalid argument

  • ESP_FAIL: Set event callbacks failed because of other error

esp_err_t esp_lcd_rgb_panel_set_pclk(esp_lcd_panel_handle_t panel, uint32_t freq_hz)

Set frequency of PCLK for RGB LCD panel.

Note

The PCLK frequency is set in the esp_lcd_rgb_timing_t and gets configured during LCD panel initialization. Usually you don't need to call this function to set the PCLK again, but in some cases, you might want to change the PCLK frequency. e.g. slow down the PCLK frequency to reduce power consumption or to reduce the memory throughput during OTA.

Note

This function doesn't cause the hardware to update the PCLK immediately but to record the new frequency and set a flag internally. Only in the next VSYNC event handler, will the driver attempt to update the PCLK frequency.

Parameters

  • panel -- [in] LCD panel handle, returned from esp_lcd_new_rgb_panel

  • freq_hz -- [in] Frequency of pixel clock, in Hz

Returns

  • ESP_ERR_INVALID_ARG: Set PCLK frequency failed because of invalid argument

  • ESP_OK: Set PCLK frequency successfully

esp_err_t esp_lcd_rgb_panel_restart(esp_lcd_panel_handle_t panel)

Restart the LCD transmission.

Note

This function can be useful when the LCD controller is out of sync with the DMA because of insufficient bandwidth. To save the screen from a permanent shift, you can call this function to restart the LCD DMA.

Note

This function doesn't restart the DMA immediately but to set a flag internally. Only in the next VSYNC event handler, will the driver attempt to do the restart job.

Note

If CONFIG_LCD_RGB_RESTART_IN_VSYNC is enabled, you don't need to call this function manually, because the restart job will be done automatically in the VSYNC event handler.

Parameters

panel -- [in] panel LCD panel handle, returned from esp_lcd_new_rgb_panel

Returns

  • ESP_ERR_INVALID_ARG: Restart the LCD failed because of invalid argument

  • ESP_ERR_INVALID_STATE: Restart the LCD failed because the LCD diver is working in refresh-on-demand mode

  • ESP_OK: Restart the LCD successfully

esp_err_t esp_lcd_rgb_panel_get_frame_buffer(esp_lcd_panel_handle_t panel, uint32_t fb_num, void **fb0, ...)

Get the address of the frame buffer(s) that allocated by the driver.

Parameters

  • panel -- [in] LCD panel handle, returned from esp_lcd_new_rgb_panel

  • fb_num -- [in] Number of frame buffer(s) to get. This value must be the same as the number of the following parameters.

  • fb0 -- [out] Returned address of the frame buffer 0

  • ... -- [out] List of other frame buffer addresses

Returns

  • ESP_ERR_INVALID_ARG: Get frame buffer address failed because of invalid argument

  • ESP_OK: Get frame buffer address successfully

esp_err_t esp_lcd_rgb_panel_refresh(esp_lcd_panel_handle_t panel)

Manually trigger once transmission of the frame buffer to the LCD panel.

Note

This function should only be called when the RGB panel is working under the refresh_on_demand mode.

Parameters

panel -- [in] LCD panel handle, returned from esp_lcd_new_rgb_panel

Returns

  • ESP_ERR_INVALID_ARG: Start a refresh failed because of invalid argument

  • ESP_ERR_INVALID_STATE: Start a refresh failed because the LCD panel is not created with the refresh_on_demand flag enabled.

  • ESP_OK: Start a refresh successfully

esp_err_t esp_lcd_rgb_panel_set_yuv_conversion(esp_lcd_panel_handle_t panel, const esp_lcd_yuv_conv_config_t *config)

Configure how to convert the color format between RGB and YUV.

Note

Pass in config as NULL will disable the RGB-YUV converter.

Note

The hardware converter can only parse a "packed" storage format, while "planar" and "semi-planar" format is not supported.

Parameters

  • panel -- [in] LCD panel handle, returned from esp_lcd_new_rgb_panel

  • config -- [in] Configuration of RGB-YUV conversion

Returns

  • ESP_ERR_INVALID_ARG: Configure RGB-YUV conversion failed because of invalid argument

  • ESP_ERR_NOT_SUPPORTED: Configure RGB-YUV conversion failed because the conversion mode is not supported by the hardware

  • ESP_OK: Configure RGB-YUV conversion successfully

Structures

struct esp_lcd_rgb_timing_t

LCD RGB timing structure. 

*                                                 Total Width
*                             <--------------------------------------------------->
*                       HSYNC width HBP             Active Width                HFP
*                             <---><--><--------------------------------------><--->
*                         ____    ____|_______________________________________|____|
*                             |___|   |                                       |    |
*                                     |                                       |    |
*                         __|         |                                       |    |
*            /|\    /|\  |            |                                       |    |
*             | VSYNC|   |            |                                       |    |
*             |Width\|/  |__          |                                       |    |
*             |     /|\     |         |                                       |    |
*             |  VBP |      |         |                                       |    |
*             |     \|/_____|_________|_______________________________________|    |
*             |     /|\     |         | / / / / / / / / / / / / / / / / / / / |    |
*             |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*    Total    |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*    Height   |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*             |Active|      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*             |Height|      |         |/ / / / / / Active Display Area / / / /|    |
*             |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*             |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*             |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*             |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*             |      |      |         |/ / / / / / / / / / / / / / / / / / / /|    |
*             |     \|/_____|_________|_______________________________________|    |
*             |     /|\     |                                                      |
*             |  VFP |      |                                                      |
*            \|/    \|/_____|______________________________________________________|
*

Public Members

uint32_t pclk_hz

Frequency of pixel clock

uint32_t h_res

Horizontal resolution, i.e. the number of pixels in a line

uint32_t v_res

Vertical resolution, i.e. the number of lines in the frame

uint32_t hsync_pulse_width

Horizontal sync width, unit: PCLK period

uint32_t hsync_back_porch

Horizontal back porch, number of PCLK between hsync and start of line active data

uint32_t hsync_front_porch

Horizontal front porch, number of PCLK between the end of active data and the next hsync

uint32_t vsync_pulse_width

Vertical sync width, unit: number of lines

uint32_t vsync_back_porch

Vertical back porch, number of invalid lines between vsync and start of frame

uint32_t vsync_front_porch

Vertical front porch, number of invalid lines between the end of frame and the next vsync

uint32_t hsync_idle_low

The hsync signal is low in IDLE state

uint32_t vsync_idle_low

The vsync signal is low in IDLE state

uint32_t de_idle_high

The de signal is high in IDLE state

uint32_t pclk_active_neg

Whether the display data is clocked out on the falling edge of PCLK

uint32_t pclk_idle_high

The PCLK stays at high level in IDLE phase

struct esp_lcd_rgb_timing_t::[anonymous] flags

LCD RGB timing flags

struct esp_lcd_rgb_panel_event_data_t

Type of RGB LCD panel event data.

struct esp_lcd_rgb_panel_event_callbacks_t

Group of supported RGB LCD panel callbacks.

Note

The callbacks are all running under ISR environment

Note

When CONFIG_LCD_RGB_ISR_IRAM_SAFE is enabled, the callback itself and functions called by it should be placed in IRAM.

Public Members

esp_lcd_rgb_panel_draw_buf_complete_cb_t on_color_trans_done

Invoked when user's color buffer copied to the internal frame buffer. This is an indicator that the draw buffer can be recycled safely. But doesn't mean the draw buffer finishes the refreshing to the screen.

esp_lcd_rgb_panel_vsync_cb_t on_vsync

VSYNC event callback

esp_lcd_rgb_panel_bounce_buf_fill_cb_t on_bounce_empty

Bounce buffer empty callback.

esp_lcd_rgb_panel_frame_buf_complete_cb_t on_bounce_frame_finish

Bounce buffer finish callback.

esp_lcd_rgb_panel_frame_buf_complete_cb_t on_frame_buf_complete

A whole frame buffer was just sent to the LCD DMA

struct esp_lcd_rgb_panel_config_t

LCD RGB panel configuration structure.

Public Members

lcd_clock_source_t clk_src

Clock source for the RGB LCD peripheral

esp_lcd_rgb_timing_t timings

RGB timing parameters, including the screen resolution

size_t data_width

Number of data lines

size_t bits_per_pixel

Frame buffer color depth, in bpp, specially, if set to zero, it will default to data_width. When using a Serial RGB interface, this value could be different from data_width

size_t num_fbs

Number of screen-sized frame buffers that allocated by the driver. By default (set to either 0 or 1) only one frame buffer will be used. Maximum number of buffers are 3

size_t bounce_buffer_size_px

If it's non-zero, the driver allocates two DRAM bounce buffers for DMA use. DMA fetching from DRAM bounce buffer is much faster than PSRAM frame buffer.

size_t sram_trans_align

Alignment of buffers (frame buffer or bounce buffer) that allocated in SRAM

size_t psram_trans_align

Alignment of buffers (frame buffer) that allocated in PSRAM

size_t dma_burst_size

DMA burst size, in bytes

int hsync_gpio_num

GPIO used for HSYNC signal

int vsync_gpio_num

GPIO used for VSYNC signal

int de_gpio_num

GPIO used for DE signal, set to -1 if it's not used

int pclk_gpio_num

GPIO used for PCLK signal, set to -1 if it's not used

int disp_gpio_num

GPIO used for display control signal, set to -1 if it's not used

int data_gpio_nums[(16)]

GPIOs used for data lines

uint32_t disp_active_low

If this flag is enabled, a low level of display control signal can turn the screen on; vice versa

uint32_t refresh_on_demand

If this flag is enabled, the host only refresh the frame buffer in esp_lcd_panel_draw_bitmap and esp_lcd_rgb_panel_refresh.

uint32_t fb_in_psram

If this flag is enabled, the frame buffer will be allocated from PSRAM, preferentially

uint32_t double_fb

If this flag is enabled, the driver will allocate two screen sized frame buffer, same as num_fbs=2

uint32_t no_fb

If this flag is enabled, the driver won't allocate frame buffer. Instead, user should fill in the bounce buffer manually in the on_bounce_empty callback

uint32_t bb_invalidate_cache

If this flag is enabled, in bounce back mode we'll do a cache invalidate on the read data, freeing the cache. Can be dangerous if data is written from other core(s).

struct esp_lcd_rgb_panel_config_t::[anonymous] flags

LCD RGB panel configuration flags

struct esp_lcd_color_conv_profile_t

LCD color conversion profile.

Public Members

lcd_color_space_t color_space

Color space of the image

lcd_color_range_t color_range

Color range of the image

lcd_yuv_sample_t yuv_sample

YUV sample format of the image

struct esp_lcd_yuv_conv_config_t

Configuration of YUG-RGB conversion.

Public Members

lcd_yuv_conv_std_t std

YUV conversion standard: BT601, BT709

esp_lcd_color_conv_profile_t src

Color conversion profile of the input image

esp_lcd_color_conv_profile_t dst

Color conversion profile of the output image

Type Definitions

typedef bool (*esp_lcd_rgb_panel_general_cb_t)(esp_lcd_panel_handle_t panel, const esp_lcd_rgb_panel_event_data_t *edata, void *user_ctx)

A general function callback prototype for RGB panel driver.

Param panel

[in] LCD panel handle, which is created by factory API like esp_lcd_new_rgb_panel

Param edata

[in] RGB panel event data, provided by driver

Param user_ctx

[in] User data, passed from esp_lcd_rgb_panel_register_event_callbacks()

Return

Whether a high priority task has been waken up by this function

typedef esp_lcd_rgb_panel_general_cb_t esp_lcd_rgb_panel_draw_buf_complete_cb_t

Declare the prototype of the function that will be invoked when the user draw buffer is complete. The draw buffer can be recycled after this event.

typedef esp_lcd_rgb_panel_general_cb_t esp_lcd_rgb_panel_frame_buf_complete_cb_t

Declare the prototype of the function that will be invoked when a whole frame buffer is sent to the LCD DMA. The LCD hardware may still need some blank time to finish the refresh.

typedef esp_lcd_rgb_panel_general_cb_t esp_lcd_rgb_panel_vsync_cb_t

Declare the prototype of the function that will be invoked when the LCD controller sends the VSYNC signal. It means, the LCD hardware should be ready, and after some blank time, the next frame will be flushed to the LCD controller.

typedef bool (*esp_lcd_rgb_panel_bounce_buf_fill_cb_t)(esp_lcd_panel_handle_t panel, void *bounce_buf, int pos_px, int len_bytes, void *user_ctx)

Prototype for function to re-fill a bounce buffer, rather than copying from the frame buffer.

Param panel

[in] LCD panel handle, returned from esp_lcd_new_rgb_panel

Param bounce_buf

[in] Bounce buffer to write data into

Param pos_px

[in] How many pixels already were sent to the display in this frame, in other words, at what pixel the routine should start putting data into bounce_buf

Param len_bytes

[in] Length, in bytes, of the bounce buffer. Routine should fill this length fully.

Param user_ctx

[in] Opaque pointer that was passed from esp_lcd_rgb_panel_register_event_callbacks()

Return

Whether a high priority task has been waken up by this function

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