LCD
Introduction
ESP chips can generate various kinds of timings that needed by common LCDs on the market, like SPI LCD, I80 LCD (a.k.a Intel 8080 parallel LCD), RGB/SRGB LCD, I2C LCD, etc. The esp_lcd
component is officially to support those LCDs with a group of universal APIs across chips.
Functional Overview
In esp_lcd
, an LCD panel is represented by esp_lcd_panel_handle_t
, which plays the role of an abstract frame buffer, regardless of the frame memory is allocated inside ESP chip or in external LCD controller. Based on the location of the frame buffer and the hardware connection interface, the LCD panel drivers are mainly grouped into the following categories:
Controller based LCD driver involves multiple steps to get a panel handle, like bus allocation, IO device registration and controller driver install. The frame buffer is located in the controller’s internal GRAM (Graphical RAM). ESP-IDF provides only a limited number of LCD controller drivers out of the box (e.g. ST7789, SSD1306), More Controller Based LCD Drivers are maintained in the Espressif Component Registry <https://components.espressif.com/>_.
SPI Interfaced LCD describes the steps to install the SPI LCD IO driver and then get the panel handle.
I2C Interfaced LCD describes the steps to install the I2C LCD IO driver and then get the panel handle.
I80 Interfaced LCD describes the steps to install the I80 LCD IO driver and then get the panel handle.
LCD Panel IO Operations - provides a set of APIs to operate the LCD panel, like turning on/off the display, setting the orientation, etc. These operations are common for either controller-based LCD panel driver or RGB LCD panel driver.
SPI Interfaced LCD
Create an SPI bus. Please refer to SPI Master API doc for more details.
spi_bus_config_t buscfg = { .sclk_io_num = EXAMPLE_PIN_NUM_SCLK, .mosi_io_num = EXAMPLE_PIN_NUM_MOSI, .miso_io_num = EXAMPLE_PIN_NUM_MISO, .quadwp_io_num = -1, // Quad SPI LCD driver is not yet supported .quadhd_io_num = -1, // Quad SPI LCD driver is not yet supported .max_transfer_sz = EXAMPLE_LCD_H_RES * 80 * sizeof(uint16_t), // transfer 80 lines of pixels (assume pixel is RGB565) at most in one SPI transaction }; ESP_ERROR_CHECK(spi_bus_initialize(LCD_HOST, &buscfg, SPI_DMA_CH_AUTO)); // Enable the DMA feature
Allocate an LCD IO device handle from the SPI bus. In this step, you need to provide the following information:
esp_lcd_panel_io_spi_config_t::dc_gpio_num
: Sets the gpio number for the DC signal line (some LCD calls thisRS
line). The LCD driver will use this GPIO to switch between sending command and sending data.esp_lcd_panel_io_spi_config_t::cs_gpio_num
: Sets the gpio number for the CS signal line. The LCD driver will use this GPIO to select the LCD chip. If the SPI bus only has one device attached (i.e. this LCD), you can set the gpio number to-1
to occupy the bus exclusively.esp_lcd_panel_io_spi_config_t::pclk_hz
sets the frequency of the pixel clock, in Hz. The value should not exceed the range recommended in the LCD spec.esp_lcd_panel_io_spi_config_t::spi_mode
sets the SPI mode. The LCD driver will use this mode to communicate with the LCD. For the meaning of the SPI mode, please refer to the SPI Master API doc.esp_lcd_panel_io_spi_config_t::lcd_cmd_bits
andesp_lcd_panel_io_spi_config_t::lcd_param_bits
set the bit width of the command and parameter that recognized by the LCD controller chip. This is chip specific, you should refer to your LCD spec in advance.esp_lcd_panel_io_spi_config_t::trans_queue_depth
sets the depth of the SPI transaction queue. A bigger value means more transactions can be queued up, but it also consumes more memory.
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, .cs_gpio_num = EXAMPLE_PIN_NUM_LCD_CS, .pclk_hz = EXAMPLE_LCD_PIXEL_CLOCK_HZ, .lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS, .lcd_param_bits = EXAMPLE_LCD_PARAM_BITS, .spi_mode = 0, .trans_queue_depth = 10, }; // Attach the LCD to the SPI bus ESP_ERROR_CHECK(esp_lcd_new_panel_io_spi((esp_lcd_spi_bus_handle_t)LCD_HOST, &io_config, &io_handle));
Install the LCD controller driver. The LCD controller driver is responsible for sending the commands and parameters to the LCD controller chip. In this step, you need to specify the SPI IO device handle that allocated in the last step, and some panel specific configurations:
esp_lcd_panel_dev_config_t::reset_gpio_num
sets the LCD’s hardware reset GPIO number. If the LCD does not have a hardware reset pin, set this to-1
.esp_lcd_panel_dev_config_t::rgb_ele_order
sets the R-G-B element order of each color data.esp_lcd_panel_dev_config_t::bits_per_pixel
sets the bit width of the pixel color data. The LCD driver uses this value to calculate the number of bytes to send to the LCD controller chip.esp_lcd_panel_dev_config_t::data_endian
specifies the data endian to be transmitted to the screen. No need to specify for color data within 1 byte, like RGB232. For drivers that do not support specifying data endian, this field would be ignored.
esp_lcd_panel_handle_t panel_handle = NULL; esp_lcd_panel_dev_config_t panel_config = { .reset_gpio_num = EXAMPLE_PIN_NUM_RST, .rgb_ele_order = LCD_RGB_ELEMENT_ORDER_BGR, .bits_per_pixel = 16, }; // Create LCD panel handle for ST7789, with the SPI IO device handle ESP_ERROR_CHECK(esp_lcd_new_panel_st7789(io_handle, &panel_config, &panel_handle));
I2C Interfaced LCD
Create I2C bus. Please refer to I2C API doc for more details.
i2c_config_t i2c_conf = { .mode = I2C_MODE_MASTER, // I2C LCD is a master node .sda_io_num = EXAMPLE_PIN_NUM_SDA, .scl_io_num = EXAMPLE_PIN_NUM_SCL, .sda_pullup_en = GPIO_PULLUP_ENABLE, .scl_pullup_en = GPIO_PULLUP_ENABLE, .master.clk_speed = EXAMPLE_LCD_PIXEL_CLOCK_HZ, }; ESP_ERROR_CHECK(i2c_param_config(I2C_HOST, &i2c_conf)); ESP_ERROR_CHECK(i2c_driver_install(I2C_HOST, I2C_MODE_MASTER, 0, 0, 0));
Allocate an LCD IO device handle from the I2C bus. In this step, you need to provide the following information:
esp_lcd_panel_io_i2c_config_t::dev_addr
sets the I2C device address of the LCD controller chip. The LCD driver will use this address to communicate with the LCD controller chip.esp_lcd_panel_io_i2c_config_t::lcd_cmd_bits
andesp_lcd_panel_io_i2c_config_t::lcd_param_bits
set the bit width of the command and parameter that recognized by the LCD controller chip. This is chip specific, you should refer to your LCD spec in advance.
esp_lcd_panel_io_handle_t io_handle = NULL; esp_lcd_panel_io_i2c_config_t io_config = { .dev_addr = EXAMPLE_I2C_HW_ADDR, .control_phase_bytes = 1, // refer to LCD spec .dc_bit_offset = 6, // refer to LCD spec .lcd_cmd_bits = EXAMPLE_LCD_CMD_BITS, .lcd_param_bits = EXAMPLE_LCD_CMD_BITS, }; ESP_ERROR_CHECK(esp_lcd_new_panel_io_i2c((esp_lcd_i2c_bus_handle_t)I2C_HOST, &io_config, &io_handle));
Install the LCD controller driver. The LCD controller driver is responsible for sending the commands and parameters to the LCD controller chip. In this step, you need to specify the I2C IO device handle that allocated in the last step, and some panel specific configurations:
esp_lcd_panel_dev_config_t::reset_gpio_num
sets the LCD’s hardware reset GPIO number. If the LCD does not have a hardware reset pin, set this to-1
.esp_lcd_panel_dev_config_t::bits_per_pixel
sets the bit width of the pixel color data. The LCD driver will use this value to calculate the number of bytes to send to the LCD controller chip.
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));
I80 Interfaced LCD
Create I80 bus by
esp_lcd_new_i80_bus()
. You need to set up the following parameters for an Intel 8080 parallel bus:esp_lcd_i80_bus_config_t::clk_src
sets the clock source of the I80 bus. Note, the default clock source may be different between ESP targets.esp_lcd_i80_bus_config_t::wr_gpio_num
sets the GPIO number of the pixel clock (also referred asWR
in some LCD spec)esp_lcd_i80_bus_config_t::dc_gpio_num
sets the GPIO number of the data/command select pin (also referred asRS
in some LCD spec)esp_lcd_i80_bus_config_t::bus_width
sets the bit width of the data bus (only support8
or16
)esp_lcd_i80_bus_config_t::data_gpio_nums
is the array of the GPIO number of the data bus. The number of GPIOs should be equal to theesp_lcd_i80_bus_config_t::bus_width
value.esp_lcd_i80_bus_config_t::max_transfer_bytes
sets the maximum number of bytes that can be transferred in one transaction.
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), // transfer 100 lines of pixels (assume pixel is RGB565) at most in one transaction .psram_trans_align = EXAMPLE_PSRAM_DATA_ALIGNMENT, .sram_trans_align = 4, }; ESP_ERROR_CHECK(esp_lcd_new_i80_bus(&bus_config, &i80_bus));
Allocate an LCD IO device handle from the I80 bus. In this step, you need to provide the following information:
esp_lcd_panel_io_i80_config_t::cs_gpio_num
sets the GPIO number of the chip select pin.esp_lcd_panel_io_i80_config_t::pclk_hz
sets the pixel clock frequency in Hz. Higher pixel clock frequency will result in higher refresh rate, but may cause flickering if the DMA bandwidth is not sufficient or the LCD controller chip does not support high pixel clock frequency.esp_lcd_panel_io_i80_config_t::lcd_cmd_bits
andesp_lcd_panel_io_i80_config_t::lcd_param_bits
set the bit width of the command and parameter that recognized by the LCD controller chip. This is chip specific, you should refer to your LCD spec in advance.esp_lcd_panel_io_i80_config_t::trans_queue_depth
sets the maximum number of transactions that can be queued in the LCD IO device. A bigger value means more transactions can be queued up, but it also consumes more memory.
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));
Install the LCD controller driver. The LCD controller driver is responsible for sending the commands and parameters to the LCD controller chip. In this step, you need to specify the I80 IO device handle that allocated in the last step, and some panel specific configurations:
esp_lcd_panel_dev_config_t::bits_per_pixel
sets the bit width of the pixel color data. The LCD driver will use this value to calculate the number of bytes to send to the LCD controller chip.esp_lcd_panel_dev_config_t::reset_gpio_num
sets the GPIO number of the reset pin. If the LCD controller chip does not have a reset pin, you can set this value to-1
.esp_lcd_panel_dev_config_t::rgb_ele_order
sets the color order the pixel color data.
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));
More Controller Based LCD Drivers
More LCD panel drivers and touch drivers are available in IDF Component Registry. The list of available and planned drivers with links is in this table.
LCD Panel IO Operations
esp_lcd_panel_reset()
can reset the LCD panel.Use
esp_lcd_panel_swap_xy()
andesp_lcd_panel_mirror()
, you can rotate the LCD screen.esp_lcd_panel_disp_on_off()
can turn on or off the LCD screen (different from LCD backlight).esp_lcd_panel_draw_bitmap()
is the most significant function, that will do the magic to draw the user provided color buffer to the LCD screen, where the draw window is also configurable.
Application Example
LCD examples are located under: peripherals/lcd:
Universal SPI LCD example with SPI touch - peripherals/lcd/spi_lcd_touch
Jpeg decoding and LCD display - peripherals/lcd/tjpgd
i80 controller based LCD and LVGL animation UI - peripherals/lcd/i80_controller
I2C interfaced OLED display scrolling text - peripherals/lcd/i2c_oled
API Reference
Header File
Macros
-
LCD_RGB_ENDIAN_RGB
-
LCD_RGB_ENDIAN_BGR
Type Definitions
-
typedef soc_periph_lcd_clk_src_t lcd_clock_source_t
LCD clock source.
-
typedef lcd_rgb_element_order_t lcd_color_rgb_endian_t
for backward compatible
Enumerations
-
enum lcd_rgb_element_order_t
RGB color endian.
Values:
-
enumerator LCD_RGB_ELEMENT_ORDER_RGB
RGB element order: RGB
-
enumerator LCD_RGB_ELEMENT_ORDER_BGR
RGB element order: BGR
-
enumerator LCD_RGB_ELEMENT_ORDER_RGB
-
enum lcd_rgb_data_endian_t
RGB data endian.
Values:
-
enumerator LCD_RGB_DATA_ENDIAN_BIG
RGB data endian: MSB first
-
enumerator LCD_RGB_DATA_ENDIAN_LITTLE
RGB data endian: LSB first
-
enumerator LCD_RGB_DATA_ENDIAN_BIG
-
enum lcd_color_space_t
LCD color space.
Values:
-
enumerator LCD_COLOR_SPACE_RGB
Color space: RGB
-
enumerator LCD_COLOR_SPACE_YUV
Color space: YUV
-
enumerator LCD_COLOR_SPACE_RGB
-
enum lcd_color_range_t
LCD color range.
Values:
-
enumerator LCD_COLOR_RANGE_LIMIT
Limited color range
-
enumerator LCD_COLOR_RANGE_FULL
Full color range
-
enumerator LCD_COLOR_RANGE_LIMIT
Header File
Type Definitions
-
typedef struct esp_lcd_panel_io_t *esp_lcd_panel_io_handle_t
Type of LCD panel IO handle
-
typedef struct esp_lcd_panel_t *esp_lcd_panel_handle_t
Type of LCD panel handle
Header File
Functions
-
esp_err_t esp_lcd_panel_io_rx_param(esp_lcd_panel_io_handle_t io, int lcd_cmd, void *param, size_t param_size)
Transmit LCD command and receive corresponding parameters.
备注
Commands sent by this function are short, so they are sent using polling transactions. The function does not return before the command transfer is completed. If any queued transactions sent by
esp_lcd_panel_io_tx_color()
are still pending when this function is called, this function will wait until they are finished and the queue is empty before sending the command(s).- 参数
io – [in] LCD panel IO handle, which is created by other factory API like
esp_lcd_new_panel_io_spi()
lcd_cmd – [in] The specific LCD command, set to -1 if no command needed
param – [out] Buffer for the command data
param_size – [in] Size of
param
buffer
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_ERR_NOT_SUPPORTED if read is not supported by transport
ESP_OK on success
-
esp_err_t esp_lcd_panel_io_tx_param(esp_lcd_panel_io_handle_t io, int lcd_cmd, const void *param, size_t param_size)
Transmit LCD command and corresponding parameters.
备注
Commands sent by this function are short, so they are sent using polling transactions. The function does not return before the command transfer is completed. If any queued transactions sent by
esp_lcd_panel_io_tx_color()
are still pending when this function is called, this function will wait until they are finished and the queue is empty before sending the command(s).- 参数
io – [in] LCD panel IO handle, which is created by other factory API like
esp_lcd_new_panel_io_spi()
lcd_cmd – [in] The specific LCD command, set to -1 if no command needed
param – [in] Buffer that holds the command specific parameters, set to NULL if no parameter is needed for the command
param_size – [in] Size of
param
in memory, in bytes, set to zero if no parameter is needed for the command
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_OK on success
-
esp_err_t esp_lcd_panel_io_tx_color(esp_lcd_panel_io_handle_t io, int lcd_cmd, const void *color, size_t color_size)
Transmit LCD RGB data.
备注
This function will package the command and RGB data into a transaction, and push into a queue. The real transmission is performed in the background (DMA+interrupt). The caller should take care of the lifecycle of the
color
buffer. Recycling of color buffer should be done in the callbackon_color_trans_done()
.- 参数
io – [in] LCD panel IO handle, which is created by factory API like
esp_lcd_new_panel_io_spi()
lcd_cmd – [in] The specific LCD command, set to -1 if no command needed
color – [in] Buffer that holds the RGB color data
color_size – [in] Size of
color
in memory, in bytes
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_OK on success
-
esp_err_t esp_lcd_panel_io_del(esp_lcd_panel_io_handle_t io)
Destroy LCD panel IO handle (deinitialize panel and free all corresponding resource)
- 参数
io – [in] LCD panel IO handle, which is created by factory API like
esp_lcd_new_panel_io_spi()
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_OK on success
-
esp_err_t esp_lcd_panel_io_register_event_callbacks(esp_lcd_panel_io_handle_t io, const esp_lcd_panel_io_callbacks_t *cbs, void *user_ctx)
Register LCD panel IO callbacks.
- 参数
io – [in] LCD panel IO handle, which is created by factory API like
esp_lcd_new_panel_io_spi()
cbs – [in] structure with all LCD panel IO callbacks
user_ctx – [in] User private data, passed directly to callback’s user_ctx
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_OK on success
-
esp_err_t esp_lcd_new_panel_io_spi(esp_lcd_spi_bus_handle_t bus, const esp_lcd_panel_io_spi_config_t *io_config, esp_lcd_panel_io_handle_t *ret_io)
Create LCD panel IO handle, for SPI interface.
- 参数
bus – [in] SPI bus handle
io_config – [in] IO configuration, for SPI 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(esp_lcd_i2c_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.
- 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
-
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
Structures
-
struct esp_lcd_panel_io_event_data_t
Type of LCD panel IO event data.
-
struct esp_lcd_panel_io_callbacks_t
Type of LCD panel IO callbacks.
Public Members
-
esp_lcd_panel_io_color_trans_done_cb_t on_color_trans_done
Callback invoked when color data transfer has finished
-
esp_lcd_panel_io_color_trans_done_cb_t on_color_trans_done
-
struct esp_lcd_panel_io_spi_config_t
Panel IO configuration structure, for SPI interface.
Public Members
-
int cs_gpio_num
GPIO used for CS line
-
int dc_gpio_num
GPIO used to select the D/C line, set this to -1 if the D/C line is not used
-
int spi_mode
Traditional SPI mode (0~3)
-
unsigned int pclk_hz
Frequency of pixel clock
-
size_t trans_queue_depth
Size of internal transaction queue
-
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
-
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 octal_mode
transmit with octal mode (8 data lines), this mode is used to simulate Intel 8080 timing
-
unsigned int quad_mode
transmit with quad mode (4 data lines), this mode is useful when transmitting LCD parameters (Only use one line for command)
-
unsigned int sio_mode
Read and write through a single data line (MOSI)
-
unsigned int lsb_first
transmit LSB bit first
-
unsigned int cs_high_active
CS line is high active
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struct esp_lcd_panel_io_spi_config_t::[anonymous] flags
Extra flags to fine-tune the SPI device
-
int cs_gpio_num
-
struct esp_lcd_panel_io_i2c_config_t
Panel IO configuration structure, for I2C interface.
Public Members
-
uint32_t dev_addr
I2C device address
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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::[anonymous] flags
Extra flags to fine-tune the I2C device
-
uint32_t dev_addr
-
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[(24)]
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 sram_trans_align
DMA transfer alignment for data allocated from SRAM
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int dc_gpio_num
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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
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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
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struct esp_lcd_panel_io_i80_config_t::[anonymous] dc_levels
Each i80 device might have its own D/C control logic
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unsigned int cs_active_high
If set, a high level of CS line will select the device, otherwise, CS line is low level active
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unsigned int reverse_color_bits
Reverse the data bits, D[N:0] -> D[0:N]
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unsigned int swap_color_bytes
Swap adjacent two color bytes
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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)
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unsigned int pclk_idle_low
The WR signal (a.k.a the PCLK) stays at low level in IDLE phase
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struct esp_lcd_panel_io_i80_config_t::[anonymous] flags
Panel IO config flags
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int cs_gpio_num
Type Definitions
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typedef void *esp_lcd_spi_bus_handle_t
Type of LCD SPI bus handle
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typedef void *esp_lcd_i2c_bus_handle_t
Type of LCD I2C bus handle
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typedef struct esp_lcd_i80_bus_t *esp_lcd_i80_bus_handle_t
Type of LCD intel 8080 bus handle
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typedef bool (*esp_lcd_panel_io_color_trans_done_cb_t)(esp_lcd_panel_io_handle_t panel_io, esp_lcd_panel_io_event_data_t *edata, void *user_ctx)
Declare the prototype of the function that will be invoked when panel IO finishes transferring color data.
- Param panel_io
[in] LCD panel IO handle, which is created by factory API like
esp_lcd_new_panel_io_spi()
- Param edata
[in] Panel IO event data, fed by driver
- Param user_ctx
[in] User data, passed from
esp_lcd_panel_io_xxx_config_t
- Return
Whether a high priority task has been waken up by this function
Header File
Functions
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esp_err_t esp_lcd_panel_reset(esp_lcd_panel_handle_t panel)
Reset LCD panel.
备注
Panel reset must be called before attempting to initialize the panel using
esp_lcd_panel_init()
.- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
- 返回
ESP_OK on success
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esp_err_t esp_lcd_panel_init(esp_lcd_panel_handle_t panel)
Initialize LCD panel.
备注
Before calling this function, make sure the LCD panel has finished the
reset
stage byesp_lcd_panel_reset()
.- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
- 返回
ESP_OK on success
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esp_err_t esp_lcd_panel_del(esp_lcd_panel_handle_t panel)
Deinitialize the LCD panel.
- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
- 返回
ESP_OK on success
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esp_err_t esp_lcd_panel_draw_bitmap(esp_lcd_panel_handle_t panel, int x_start, int y_start, int x_end, int y_end, const void *color_data)
Draw bitmap on LCD panel.
- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
x_start – [in] Start index on x-axis (x_start included)
y_start – [in] Start index on y-axis (y_start included)
x_end – [in] End index on x-axis (x_end not included)
y_end – [in] End index on y-axis (y_end not included)
color_data – [in] RGB color data that will be dumped to the specific window range
- 返回
ESP_OK on success
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esp_err_t esp_lcd_panel_mirror(esp_lcd_panel_handle_t panel, bool mirror_x, bool mirror_y)
Mirror the LCD panel on specific axis.
备注
Combined with
esp_lcd_panel_swap_xy()
, one can realize screen rotation- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
mirror_x – [in] Whether the panel will be mirrored about the x axis
mirror_y – [in] Whether the panel will be mirrored about the y axis
- 返回
ESP_OK on success
ESP_ERR_NOT_SUPPORTED if this function is not supported by the panel
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esp_err_t esp_lcd_panel_swap_xy(esp_lcd_panel_handle_t panel, bool swap_axes)
Swap/Exchange x and y axis.
备注
Combined with
esp_lcd_panel_mirror()
, one can realize screen rotation- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
swap_axes – [in] Whether to swap the x and y axis
- 返回
ESP_OK on success
ESP_ERR_NOT_SUPPORTED if this function is not supported by the panel
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esp_err_t esp_lcd_panel_set_gap(esp_lcd_panel_handle_t panel, int x_gap, int y_gap)
Set extra gap in x and y axis.
The gap is the space (in pixels) between the left/top sides of the LCD panel and the first row/column respectively of the actual contents displayed.
备注
Setting a gap is useful when positioning or centering a frame that is smaller than the LCD.
- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
x_gap – [in] Extra gap on x axis, in pixels
y_gap – [in] Extra gap on y axis, in pixels
- 返回
ESP_OK on success
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esp_err_t esp_lcd_panel_invert_color(esp_lcd_panel_handle_t panel, bool invert_color_data)
Invert the color (bit-wise invert the color data line)
- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
invert_color_data – [in] Whether to invert the color data
- 返回
ESP_OK on success
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esp_err_t esp_lcd_panel_disp_on_off(esp_lcd_panel_handle_t panel, bool on_off)
Turn on or off the display.
- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
on_off – [in] True to turns on display, False to turns off display
- 返回
ESP_OK on success
ESP_ERR_NOT_SUPPORTED if this function is not supported by the panel
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esp_err_t esp_lcd_panel_disp_off(esp_lcd_panel_handle_t panel, bool off)
Turn off the display.
- 参数
panel – [in] LCD panel handle, which is created by other factory API like
esp_lcd_new_panel_st7789()
off – [in] Whether to turn off the screen
- 返回
ESP_OK on success
ESP_ERR_NOT_SUPPORTED if this function is not supported by the panel
Header File
Header File
Functions
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esp_err_t esp_lcd_new_panel_st7789(const esp_lcd_panel_io_handle_t io, const esp_lcd_panel_dev_config_t *panel_dev_config, esp_lcd_panel_handle_t *ret_panel)
Create LCD panel for model ST7789.
- 参数
io – [in] LCD panel IO handle
panel_dev_config – [in] general panel device configuration
ret_panel – [out] Returned LCD panel handle
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_ERR_NO_MEM if out of memory
ESP_OK on success
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esp_err_t esp_lcd_new_panel_nt35510(const esp_lcd_panel_io_handle_t io, const esp_lcd_panel_dev_config_t *panel_dev_config, esp_lcd_panel_handle_t *ret_panel)
Create LCD panel for model NT35510.
- 参数
io – [in] LCD panel IO handle
panel_dev_config – [in] general panel device configuration
ret_panel – [out] Returned LCD panel handle
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_ERR_NO_MEM if out of memory
ESP_OK on success
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esp_err_t esp_lcd_new_panel_ssd1306(const esp_lcd_panel_io_handle_t io, const esp_lcd_panel_dev_config_t *panel_dev_config, esp_lcd_panel_handle_t *ret_panel)
Create LCD panel for model SSD1306.
- 参数
io – [in] LCD panel IO handle
panel_dev_config – [in] general panel device configuration
ret_panel – [out] Returned LCD panel handle
- 返回
ESP_ERR_INVALID_ARG if parameter is invalid
ESP_ERR_NO_MEM if out of memory
ESP_OK on success
Structures
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struct esp_lcd_panel_dev_config_t
Configuration structure for panel device.
Public Members
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int reset_gpio_num
GPIO used to reset the LCD panel, set to -1 if it’s not used
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lcd_rgb_element_order_t color_space
- Deprecated:
Set RGB color space, please use rgb_ele_order instead
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lcd_rgb_element_order_t rgb_endian
- Deprecated:
Set RGB data endian, please use rgb_ele_order instead
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lcd_rgb_element_order_t rgb_ele_order
Set RGB element order, RGB or BGR
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lcd_rgb_data_endian_t data_endian
Set the data endian for color data larger than 1 byte
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unsigned int bits_per_pixel
Color depth, in bpp
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unsigned int reset_active_high
Setting this if the panel reset is high level active
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struct esp_lcd_panel_dev_config_t::[anonymous] flags
LCD panel config flags
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void *vendor_config
vendor specific configuration, optional, left as NULL if not used
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int reset_gpio_num