API.md

API Reference

🔢 CAPABILITIES	💾 SD CARD AND SPIFFS	🎵 AUDIO	📟 DISPLAY AND TOUCH	🔌 USB	📷 CAMERA

Overview

This document provides an overview of the ESP-BSP (Board Support Package) API as implemented by this board.

While the ESP-BSP framework defines a unified API shared across multiple boards, this documentation focuses only on the APIs supported by the current board. Any APIs not applicable to this board's hardware are excluded or may not be functional.

The goal of this document is to make it easier for developers to understand the available APIs and how to use them consistently across different boards.

General

Pinout

Each BSP defines a set of macros for default pin assignments used by its hardware peripherals. These macros allow users to configure or reference standard interfaces like I2C, SPI, LCD, audio, or SD cards easily.

• I2C: BSP_I2C_*
• Display: BSP_LCD_*
• Audio I2S: BSP_I2S_*
• USB: BSP_USB_*
• SD Card (MMC): BSP_SD_*
• SD Card (SPI): BSP_SD_SPI_*

Note

Not all boards support all interfaces. You should always check if the related capability macro (e.g., BSP_CAPS_SDCARD) is defined.

I2C

Some devices included in BSPs (e.g., sensors, displays, audio codecs) communicate via the I2C interface. In many cases, I2C is initialized automatically as part of the device setup. However, you can manually initialize or deinitialize the I2C peripheral using the following API:

/* Initialize the default I2C bus used by the BSP */
bsp_i2c_init();

...

/* Deinitialize the I2C bus */
bsp_i2c_deinit();

If you need direct access to the initialized I2C bus (e.g., to communicate with an external peripheral not handled by the BSP), you can retrieve the I2C bus handle:

i2c_master_bus_handle_t i2c = bsp_i2c_get_handle();

Note

The BSP ensures that I2C initialization is performed only once, even if called multiple times. This helps avoid conflicts when multiple components rely on the same I2C bus.

ADC

Some devices included in BSPs (such as buttons, battery monitoring, etc.) use the ADC peripheral. In most cases, the ADC is automatically initialized as part of the specific device setup. However, you can manually initialize the ADC using the following API:

/* Initialize the ADC peripheral */
bsp_adc_initialize();

If you need direct access to the ADC instance (e.g., for custom measurements), you can retrieve the handle:

adc_oneshot_unit_handle_t adc = bsp_adc_get_handle();

Note

The BSP ensures the ADC is initialized only once, even if bsp_adc_initialize() is called multiple times.

Features

Some boards support enabling or disabling specific hardware features (such as LCD, SD card, camera, etc.) to reduce power consumption or manage shared resources. The BSP provides a unified API to control these features:

/* Enable the LCD feature */
bsp_feature_enable(BSP_FEATURE_LCD, true);

/* Disable the speaker to reduce power usage */
bsp_feature_enable(BSP_FEATURE_SPEAKER, false);

Supported feature flags (may vary depending on the board):

• BSP_FEATURE_LCD - Display module
• BSP_FEATURE_TOUCH - Touch controller
• BSP_FEATURE_SD - SD card interface
• BSP_FEATURE_SPEAKER- Audio speaker
• BSP_FEATURE_BATTERY - Battery monitoring
• BSP_FEATURE_VIBRATION - Vibration motor

Note

Not all BSPs support feature toggling, and some features may not be available or controllable via this API. Always check the BSP header or documentation for supported features.

Tip

Disabling unused features can help reduce power consumption, especially in battery-powered applications.

Identification

Each BSP defines an identifier macro in the form of BSP_BOARD_*.

Board Name API Reference

Macros

Type	Name
define	BSP_BOARD_M5STACK_CORE_S3

🔢 Capabilities

Each BSP defines a set of capability macros that indicate which features are supported. The list may look like this. You can use these macros to conditionally compile code depending on feature availability.

Capabilities API Reference

Macros

Type	Name
define	BSP_CAPS_AUDIO 1
define	BSP_CAPS_AUDIO_MIC 1
define	BSP_CAPS_AUDIO_SPEAKER 1
define	BSP_CAPS_BUTTONS 0
define	BSP_CAPS_CAMERA 1
define	BSP_CAPS_DISPLAY 1
define	BSP_CAPS_IMU 0
define	BSP_CAPS_SDCARD 1
define	BSP_CAPS_TOUCH 1

I2C API Reference

Functions

Type	Name
esp_err_t	bsp_i2c_deinit (void) Deinit I2C driver and free its resources.
esp_err_t	bsp_i2c_init (void) Init I2C driver.

Macros

Type	Name
define	BSP_I2C_NUM CONFIG_BSP_I2C_NUM
define	BSP_I2C_SCL (GPIO_NUM_11)
define	BSP_I2C_SDA (GPIO_NUM_12)

Functions Documentation

function bsp_i2c_deinit

Deinit I2C driver and free its resources.

esp_err_t bsp_i2c_deinit (
    void
) 

Returns:

• ESP_OK On success
• ESP_ERR_INVALID_ARG I2C parameter error

function bsp_i2c_init

Init I2C driver.

esp_err_t bsp_i2c_init (
    void
) 

Returns:

• ESP_OK On success
• ESP_ERR_INVALID_ARG I2C parameter error
• ESP_FAIL I2C driver installation error

💾 SD Card and SPIFFS

SPIFFS Initialization / Deinitialization

Each BSP provides a simple API for mounting and unmounting the SPI Flash File System (SPIFFS).

/* Mount SPIFFS to the virtual file system */
bsp_spiffs_mount();

/* ... perform file operations ... */

/* Unmount SPIFFS from the virtual file system */
bsp_spiffs_unmount();

SD Card Initialization / Deinitialization

The SD Card and LCD share an SPI bus. https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/peripherals/sdspi_share.html The SD Card is mounted during the bsp_display_start() process and occurs during the bsp_display_mount() function if the SDCARD capability is set using BSP_CAPS_SDCARD macro. Do not use the the default mount API "bsp_sdcard_mount()" The BSP offers a flexible API for working with SD cards. File operations and unmount functions remain unchanged. You can also use a configuration structure or access preconfigured host and slot structures.

Mount with Default Configuration

/* Mount microSD card to the virtual file system */
** Mounting occurs automatically during bsp_display_start() process **

/* ... perform file operations ... */

/* Unmount microSD card */
bsp_sdcard_unmount();

Mount with Custom Configuration

Some BSPs allow selecting between SDMMC and SPI interfaces for the SD card. Use the appropriate API function based on your hardware:

bsp_sdcard_cfg_t cfg = {0};
/* Mount SD card using SDMMC interface */
bsp_sdcard_sdmmc_mount(&cfg);

or

bsp_sdcard_cfg_t cfg = {0};
/* Mount SD card using SPI interface */
bsp_sdcard_sdspi_mount(&cfg)

Note

Not all BSPs support both SDMMC and SPI modes. Check the board documentation to see which interfaces are available. If an unsupported interface is used, the API will return ESP_ERR_NOT_SUPPORTED error.

After Mounting

Once the SD card or SPIFFS is mounted, you can use standard file I/O functions (fopen, fread, fwrite, fclose, etc.) provided by ESP-IDF's VFS (Virtual File System).

To print basic SD card information (after mounting), you can use:

sdmmc_card_t *sdcard = bsp_sdcard_get_handle();
sdmmc_card_print_info(stdout, sdcard);

Tip

The bsp_sdcard_get_handle() function returns a pointer to the sdmmc_card_t structure, which contains detailed information about the connected SD card.

SD Card and SPIFFS API Reference

Structures and Types

Type	Name
struct	bsp_sdcard_cfg_t BSP SD card configuration structure.

Functions

Type	Name
sdmmc_card_t *	bsp_sdcard_get_handle (void) Get SD card handle.
void	bsp_sdcard_get_sdmmc_host (const int slot, sdmmc_host_t *config) Get SD card MMC host config.
void	bsp_sdcard_get_sdspi_host (const int slot, sdmmc_host_t *config) Get SD card SPI host config.
esp_err_t	bsp_sdcard_mount (void) Mount microSD card to virtual file system.
void	bsp_sdcard_sdmmc_get_slot (const int slot, sdmmc_slot_config_t *config) Get SD card MMC slot config.
esp_err_t	bsp_sdcard_sdmmc_mount (bsp_sdcard_cfg_t *cfg) Mount microSD card to virtual file system (MMC mode)
void	bsp_sdcard_sdspi_get_slot (const spi_host_device_t spi_host, sdspi_device_config_t *config) Get SD card SPI slot config.
esp_err_t	bsp_sdcard_sdspi_mount (bsp_sdcard_cfg_t *cfg) Mount microSD card to virtual file system (SPI mode)
esp_err_t	bsp_sdcard_unmount (void) Unmount microSD card from virtual file system.
esp_err_t	bsp_spiffs_mount (void) Mount SPIFFS to virtual file system.
esp_err_t	bsp_spiffs_unmount (void) Unmount SPIFFS from virtual file system.

Macros

Type	Name
define	BSP_SDSPI_HOST (SPI3_HOST)
define	BSP_SD_MOUNT_POINT CONFIG_BSP_SD_MOUNT_POINT
define	BSP_SD_SPI_CS (GPIO_NUM_4)
define	BSP_SD_SPI_MISO (GPIO_NUM_35)
define	BSP_SD_SPI_MOSI (GPIO_NUM_37)
define	BSP_SD_SPI_SCK (GPIO_NUM_36)
define	BSP_SPIFFS_MOUNT_POINT CONFIG_BSP_SPIFFS_MOUNT_POINT

Structures and Types Documentation

struct bsp_sdcard_cfg_t

BSP SD card configuration structure.

Variables:

• sdmmc_host_t * host

• const esp_vfs_fat_sdmmc_mount_config_t * mount

• const sdmmc_slot_config_t * sdmmc

• const sdspi_device_config_t * sdspi

• union bsp_sdcard_cfg_t slot

Functions Documentation

function bsp_sdcard_get_handle

Get SD card handle.

sdmmc_card_t * bsp_sdcard_get_handle (
    void
) 

Returns:

SD card handle

function bsp_sdcard_get_sdmmc_host

Get SD card MMC host config.

void bsp_sdcard_get_sdmmc_host (
    const int slot,
    sdmmc_host_t *config
) 

Parameters:

• slot SD card slot
• config Structure which will be filled

function bsp_sdcard_get_sdspi_host

Get SD card SPI host config.

void bsp_sdcard_get_sdspi_host (
    const int slot,
    sdmmc_host_t *config
) 

Parameters:

• slot SD card slot
• config Structure which will be filled

function bsp_sdcard_mount

Mount microSD card to virtual file system.

esp_err_t bsp_sdcard_mount (
    void
) 

Returns:

• ESP_OK on success
• ESP_ERR_INVALID_STATE if esp_vfs_fat_sdmmc_mount was already called
• ESP_ERR_NO_MEM if memory can not be allocated
• ESP_FAIL if partition can not be mounted
• other error codes from SDMMC or SPI drivers, SDMMC protocol, or FATFS drivers

function bsp_sdcard_sdmmc_get_slot

Get SD card MMC slot config.

void bsp_sdcard_sdmmc_get_slot (
    const int slot,
    sdmmc_slot_config_t *config
) 

Parameters:

• slot SD card slot
• config Structure which will be filled

function bsp_sdcard_sdmmc_mount

Mount microSD card to virtual file system (MMC mode)

esp_err_t bsp_sdcard_sdmmc_mount (
    bsp_sdcard_cfg_t *cfg
) 

Parameters:

• cfg SD card configuration

Returns:

• ESP_OK on success
• ESP_ERR_INVALID_STATE if esp_vfs_fat_sdmmc_mount was already called
• ESP_ERR_NO_MEM if memory cannot be allocated
• ESP_FAIL if partition cannot be mounted
• other error codes from SDMMC or SPI drivers, SDMMC protocol, or FATFS drivers

function bsp_sdcard_sdspi_get_slot

Get SD card SPI slot config.

void bsp_sdcard_sdspi_get_slot (
    const spi_host_device_t spi_host,
    sdspi_device_config_t *config
) 

Parameters:

• spi_host SPI host ID
• config Structure which will be filled

function bsp_sdcard_sdspi_mount

Mount microSD card to virtual file system (SPI mode)

esp_err_t bsp_sdcard_sdspi_mount (
    bsp_sdcard_cfg_t *cfg
) 

Parameters:

• cfg SD card configuration

Returns:

• ESP_OK on success
• ESP_ERR_INVALID_STATE if esp_vfs_fat_sdmmc_mount was already called
• ESP_ERR_NO_MEM if memory cannot be allocated
• ESP_FAIL if partition cannot be mounted
• other error codes from SDMMC or SPI drivers, SDMMC protocol, or FATFS drivers

function bsp_sdcard_unmount

Unmount microSD card from virtual file system.

esp_err_t bsp_sdcard_unmount (
    void
) 

Returns:

• ESP_OK on success
• ESP_ERR_NOT_FOUND if the partition table does not contain FATFS partition with given label
• ESP_ERR_INVALID_STATE if esp_vfs_fat_spiflash_mount was already called
• ESP_ERR_NO_MEM if memory can not be allocated
• ESP_FAIL if partition can not be mounted
• other error codes from wear levelling library, SPI flash driver, or FATFS drivers

function bsp_spiffs_mount

Mount SPIFFS to virtual file system.

esp_err_t bsp_spiffs_mount (
    void
) 

Returns:

• ESP_OK on success
• ESP_ERR_INVALID_STATE if esp_vfs_spiffs_register was already called
• ESP_ERR_NO_MEM if memory can not be allocated
• ESP_FAIL if partition can not be mounted
• other error codes

function bsp_spiffs_unmount

Unmount SPIFFS from virtual file system.

esp_err_t bsp_spiffs_unmount (
    void
) 

Returns:

• ESP_OK on success
• ESP_ERR_NOT_FOUND if the partition table does not contain SPIFFS partition with given label
• ESP_ERR_INVALID_STATE if esp_vfs_spiffs_unregister was already called
• ESP_ERR_NO_MEM if memory can not be allocated
• ESP_FAIL if partition can not be mounted
• other error codes

🎵 Audio

Initialization

Before using speaker or microphone features, the audio codec must be initialized.

/* Initialize the speaker codec */
esp_codec_dev_handle_t spk_codec_dev = bsp_audio_codec_speaker_init();

/* Initialize the microphone codec */
esp_codec_dev_handle_t mic_codec_dev = bsp_audio_codec_microphone_init();

After initialization, the esp_codec_dev API can be used to control playback and recording.

Note

Some BSPs may only support playback (speaker) or only input (microphone). Use the capability macros (BSP_CAPS_AUDIO, BSP_CAPS_AUDIO_SPEAKER, BSP_CAPS_AUDIO_MIC) to check supported features.

Example of audio usage

Speaker

Below is an example of audio playback using the speaker (source data not included):

/* Set volume to 50% */
esp_codec_dev_set_out_vol(spk_codec_dev, 50);

/* Define audio format */
esp_codec_dev_sample_info_t fs = {
    .sample_rate = wav_header.sample_rate,
    .channel = wav_header.num_channels,
    .bits_per_sample = wav_header.bits_per_sample,
};
/* Open speaker stream */
esp_codec_dev_open(spk_codec_dev, &fs);

...
/* Play audio data */
esp_codec_dev_write(spk_codec_dev, wav_bytes, wav_bytes_len);
...

/* Close stream when done */
esp_codec_dev_close(spk_codec_dev);

Tip

Audio data must be in raw PCM format. Use a decoder if playing compressed formats (e.g., WAV, MP3).

Microphone

Below is an example of recording audio using the microphone (destination buffer not included):

/* Set input gain (optional) */
esp_codec_dev_set_in_gain(mic_codec_dev, 42.0);

/* Define audio format */
esp_codec_dev_sample_info_t fs = {
    .sample_rate = 16000,
    .channel = 1,
    .bits_per_sample = 16,
};
/* Open microphone stream */
esp_codec_dev_open(mic_codec_dev, &fs);

/* Read recorded data */
esp_codec_dev_read(mic_codec_dev, recording_buffer, BUFFER_SIZE)

...

/* Close stream when done */
esp_codec_dev_close(mic_codec_dev);

Audio API Reference

Functions

Type	Name
esp_codec_dev_handle_t	bsp_audio_codec_microphone_init (void) Initialize microphone codec device.
esp_codec_dev_handle_t	bsp_audio_codec_speaker_init (void) Initialize speaker codec device.
const audio_codec_data_if_t *	bsp_audio_get_codec_itf (void) Get codec I2S interface (initialized in bsp_audio_init)
esp_err_t	bsp_audio_init (const i2s_std_config_t *i2s_config) Init audio.

Macros

Type	Name
define	BSP_I2S_DOUT (GPIO_NUM_13)
define	BSP_I2S_DSIN (GPIO_NUM_14)
define	BSP_I2S_LCLK (GPIO_NUM_33)
define	BSP_I2S_MCLK (GPIO_NUM_0)
define	BSP_I2S_SCLK (GPIO_NUM_34)
define	BSP_MUTE_STATUS (GPIO_NUM_NC)
define	BSP_POWER_AMP_IO (GPIO_NUM_NC)

Functions Documentation

function bsp_audio_codec_microphone_init

Initialize microphone codec device.

esp_codec_dev_handle_t bsp_audio_codec_microphone_init (
    void
) 

Returns:

Pointer to codec device handle or NULL when error occured

function bsp_audio_codec_speaker_init

Initialize speaker codec device.

esp_codec_dev_handle_t bsp_audio_codec_speaker_init (
    void
) 

Returns:

Pointer to codec device handle or NULL when error occured

function bsp_audio_get_codec_itf

Get codec I2S interface (initialized in bsp_audio_init)

const audio_codec_data_if_t * bsp_audio_get_codec_itf (
    void
) 

Returns:

• Pointer to codec I2S interface handle or NULL when error occured

function bsp_audio_init

Init audio.

esp_err_t bsp_audio_init (
    const i2s_std_config_t *i2s_config
) 

Note:

There is no deinit audio function. Users can free audio resources by calling i2s_del_channel()

Warning:

The type of i2s_config param is depending on IDF version.

Parameters:

• i2s_config I2S configuration. Pass NULL to use default values (Mono, duplex, 16bit, 22050 Hz)

Returns:

• ESP_OK On success
• ESP_ERR_NOT_SUPPORTED The communication mode is not supported on the current chip
• ESP_ERR_INVALID_ARG NULL pointer or invalid configuration
• ESP_ERR_NOT_FOUND No available I2S channel found
• ESP_ERR_NO_MEM No memory for storing the channel information
• ESP_ERR_INVALID_STATE This channel has not initialized or already started

📟 Display and Touch

Initialization

ESP-BSP provides two ways to initialize the display, touch and LVGL.

Simple method:

/* Initialize display, touch, and LVGL */
lv_display_t display = bsp_display_start();

Configurable method:

bsp_display_cfg_t cfg = {
    .lvgl_port_cfg = ESP_LVGL_PORT_INIT_CONFIG(),   /* See LVGL Port for more info */
    .buffer_size = BSP_LCD_V_RES * BSP_LCD_H_RES,   /* Screen buffer size in pixels */
    .double_buffer = true,                          /* Allocate two buffers if true */
    .flags = {
        .buff_dma = true,                           /* Use DMA-capable LVGL buffer */
        .buff_spiram = false,                       /* Allocate buffer in PSRAM if true */
    }
};
cfg.lvgl_port_cfg.task_stack = 10000;   /* Example: change LVGL task stack size */
/* Initialize display, touch, and LVGL */
lv_display_t display = bsp_display_start_with_config(&cfg);

After initialization, you can use the LVGL API or LVGL Port API.

Initialization without LVGL - NoGLIB BSP

To initialize the LCD without LVGL, use:

esp_lcd_panel_handle_t panel_handle;
esp_lcd_panel_io_handle_t io_handle;
const bsp_display_config_t bsp_disp_cfg = {
    .max_transfer_sz = (BSP_LCD_H_RES * 100) * sizeof(uint16_t),
};
BSP_ERROR_CHECK_RETURN_NULL(bsp_display_new(&bsp_disp_cfg, &panel_handle, &io_handle));

To initialize the LCD touch without LVGL, use:

esp_lcd_touch_handle_t tp;
bsp_touch_new(NULL, &tp);

After initialization, you can use the ESP-LCD API and ESP-LCD Touch API.

Set Brightness

/* Set display brightness to 100% */
bsp_display_backlight_on();

/* Set display brightness to 0% */
bsp_display_backlight_off();

/* Set display brightness to 50% */
bsp_display_brightness_set(50);

Note

Some boards do not support changing brightness. They return an ESP_ERR_NOT_SUPPORTED error.

LVGL API Usage (only when initialized with LVGL)

All LVGL calls must be protected using lock/unlock:

/* Wait until other tasks finish screen operations */
bsp_display_lock(0);
...
lv_obj_t * screen = lv_disp_get_scr_act(disp_handle);
lv_obj_t * obj = lv_label_create(screen);
...
/* Unlock after screen operations are done */
bsp_display_unlock();

Screen rotation (only when initialized with LVGL)

bsp_display_lock(0);
/* Rotate display to 90 */
bsp_display_rotate(display, LV_DISPLAY_ROTATION_90);
bsp_display_unlock();

Note

Some LCDs do not support hardware rotation and instead use software rotation, which consumes more memory.

Available constants

Constants like screen resolution, pin configuration, and other options are defined in the BSP header files ({bsp_name}.h, display.h, touch.h). Below are some of the most relevant predefined constants:

• BSP_LCD_H_RES - Horizontal resolution in pixels
• BSP_LCD_V_RES - Vertical resolution in pixels
• BSP_LCD_SPI_NUM - SPI bus used by the LCD (if applicable)

Display and Touch API Reference

Structures and Types

Type	Name
struct	bsp_display_cfg_t BSP display configuration structure.
struct	bsp_display_config_t BSP display configuration structure.
struct	bsp_touch_config_t BSP touch configuration structure.

Functions

Type	Name
esp_err_t	bsp_display_backlight_off (void) Turn off display backlight.
esp_err_t	bsp_display_backlight_on (void) Turn on display backlight.
esp_err_t	bsp_display_brightness_init (void) Initialize display's brightness.
esp_err_t	bsp_display_brightness_set (int brightness_percent) Set display's brightness.
lv_indev_t *	bsp_display_get_input_dev (void) Get pointer to input device (touch, buttons, ...)
bool	bsp_display_lock (uint32_t timeout_ms) Take LVGL mutex.
esp_err_t	bsp_display_new (const bsp_display_config_t *config, esp_lcd_panel_handle_t *ret_panel, esp_lcd_panel_io_handle_t *ret_io) Create new display panel.
void	bsp_display_rotate (lv_display_t *disp, lv_display_rotation_t rotation) Rotate screen.
lv_display_t *	bsp_display_start (void) Initialize display.
lv_display_t *	bsp_display_start_with_config (const bsp_display_cfg_t *cfg) Initialize display.
void	bsp_display_unlock (void) Give LVGL mutex.
esp_err_t	bsp_touch_new (const bsp_touch_config_t *config, esp_lcd_touch_handle_t *ret_touch) Create new touchscreen.

Macros

Type	Name
define	BSP_LCD_BACKLIGHT (GPIO_NUM_NC)
define	BSP_LCD_BIGENDIAN (1)
define	BSP_LCD_BITS_PER_PIXEL (16)
define	BSP_LCD_COLOR_FORMAT (ESP_LCD_COLOR_FORMAT_RGB565)
define	BSP_LCD_COLOR_SPACE (LCD_RGB_ELEMENT_ORDER_BGR)
define	BSP_LCD_CS (GPIO_NUM_3)
define	BSP_LCD_DC (GPIO_NUM_35)
define	BSP_LCD_DRAW_BUFF_DOUBLE (1)
define	BSP_LCD_DRAW_BUFF_SIZE (BSP_LCD_H_RES * 50)
define	BSP_LCD_H_RES (320)
define	BSP_LCD_MISO (GPIO_NUM_35)
define	BSP_LCD_MOSI (GPIO_NUM_37)
define	BSP_LCD_PCLK (GPIO_NUM_36)
define	BSP_LCD_PIXEL_CLOCK_HZ (40 * 1000 * 1000)
define	BSP_LCD_RST (GPIO_NUM_NC)
define	BSP_LCD_SPI_NUM (SPI3_HOST)
define	BSP_LCD_TOUCH_INT (GPIO_NUM_NC)
define	BSP_LCD_V_RES (240)
define	ESP_LCD_COLOR_FORMAT_RGB565 (1)
define	ESP_LCD_COLOR_FORMAT_RGB888 (2)

Structures and Types Documentation

struct bsp_display_cfg_t

BSP display configuration structure.

Variables:

• unsigned int buff_dma
  Allocated LVGL buffer will be DMA capable

• unsigned int buff_spiram
  Allocated LVGL buffer will be in PSRAM

• uint32_t buffer_size
  Size of the buffer for the screen in pixels

• bool double_buffer
  True, if should be allocated two buffers

• struct bsp_display_cfg_t flags

• lvgl_port_cfg_t lvgl_port_cfg
  LVGL port configuration

struct bsp_display_config_t

BSP display configuration structure.

Variables:

• int max_transfer_sz
  Maximum transfer size, in bytes.

struct bsp_touch_config_t

BSP touch configuration structure.

Variables:

• void * dummy
  Prepared for future use.

Functions Documentation

function bsp_display_backlight_off

Turn off display backlight.

esp_err_t bsp_display_backlight_off (
    void
) 

Backlight must be already initialized by calling bsp_display_brightness_init() orbsp_display_start()

Returns:

• ESP_OK On success
• ESP_ERR_INVALID_ARG Parameter error

function bsp_display_backlight_on

Turn on display backlight.

esp_err_t bsp_display_backlight_on (
    void
) 

Backlight must be already initialized by calling bsp_display_brightness_init() orbsp_display_start()

Returns:

• ESP_OK On success
• ESP_ERR_INVALID_ARG Parameter error

function bsp_display_brightness_init

Initialize display's brightness.

esp_err_t bsp_display_brightness_init (
    void
) 

Brightness is controlled with AXP2101 via I2C.

Returns:

• ESP_OK On success
• ESP_ERR_INVALID_ARG Parameter error

function bsp_display_brightness_set

Set display's brightness.

esp_err_t bsp_display_brightness_set (
    int brightness_percent
) 

Brightness is controlled with AXP2101 via I2C. Backlight must be already initialized by calling bsp_display_brightness_init() orbsp_display_start()

Parameters:

• brightness_percent Brightness in [%]

Returns:

• ESP_OK On success
• ESP_ERR_INVALID_ARG Parameter error

function bsp_display_get_input_dev

Get pointer to input device (touch, buttons, ...)

lv_indev_t * bsp_display_get_input_dev (
    void
) 

Note:

The LVGL input device is initialized in bsp_display_start() function.

Returns:

Pointer to LVGL input device or NULL when not initialized

function bsp_display_lock

Take LVGL mutex.

bool bsp_display_lock (
    uint32_t timeout_ms
) 

Parameters:

• timeout_ms Timeout in [ms]. 0 will block indefinitely.

Returns:

true Mutex was taken

Returns:

false Mutex was NOT taken

function bsp_display_new

Create new display panel.

esp_err_t bsp_display_new (
    const bsp_display_config_t *config,
    esp_lcd_panel_handle_t *ret_panel,
    esp_lcd_panel_io_handle_t *ret_io
) 

For maximum flexibility, this function performs only reset and initialization of the display. You must turn on the display explicitly by calling esp_lcd_panel_disp_on_off(). The display's backlight is not turned on either. You can use bsp_display_backlight_on/off(), bsp_display_brightness_set() (on supported boards) or implement your own backlight control.

If you want to free resources allocated by this function, you can use esp_lcd API, ie.:

esp_lcd_panel_del(panel);
esp_lcd_panel_io_del(io);
spi_bus_free(spi_num_from_configuration);

Parameters:

• config display configuration
• ret_panel esp_lcd panel handle
• ret_io esp_lcd IO handle

Returns:

• ESP_OK On success
• Else esp_lcd failure

function bsp_display_rotate

Rotate screen.

void bsp_display_rotate (
    lv_display_t *disp,
    lv_display_rotation_t rotation
) 

Display must be already initialized by calling bsp_display_start()

Parameters:

• disp Pointer to LVGL display
• rotation Angle of the display rotation

function bsp_display_start

Initialize display.

lv_display_t * bsp_display_start (
    void
) 

This function initializes SPI, display controller and starts LVGL handling task. LCD backlight must be enabled separately by calling bsp_display_brightness_set()

Returns:

Pointer to LVGL display or NULL when error occured

function bsp_display_start_with_config

Initialize display.

lv_display_t * bsp_display_start_with_config (
    const bsp_display_cfg_t *cfg
) 

This function initializes SPI, display controller and starts LVGL handling task. LCD backlight must be enabled separately by calling bsp_display_brightness_set()

Parameters:

• cfg display configuration

Returns:

Pointer to LVGL display or NULL when error occured

function bsp_display_unlock

Give LVGL mutex.

void bsp_display_unlock (
    void
) 

function bsp_touch_new

Create new touchscreen.

esp_err_t bsp_touch_new (
    const bsp_touch_config_t *config,
    esp_lcd_touch_handle_t *ret_touch
) 

If you want to free resources allocated by this function, you can use esp_lcd_touch API, ie.:

esp_lcd_touch_del(tp);

Parameters:

• config touch configuration
• ret_touch esp_lcd_touch touchscreen handle

Returns:

• ESP_OK On success
• Else esp_lcd_touch failure

🔌 USB

Boards with USB support define macros for USB pins, such as BSP_USB_POS and BSP_USB_NEG, and may also provide control APIs for enabling or disabling USB functionality.

/* Initialize USB in device mode and enable power */
bsp_usb_host_start(BSP_USB_HOST_POWER_MODE_USB_DEV, true);

...
/* Deinitialize and stop USB */
bsp_usb_host_stop();

Note

Not all BSPs implement USB support or provide power control. Refer to the board's documentation and the BSP header files for available functions and supported modes.

For more USB-related APIs and configuration options, check the corresponding BSP header files.

USB API Reference

Macros

Type	Name
define	BSP_USB_NEG (GPIO_NUM_19)
define	BSP_USB_POS (GPIO_NUM_20)

📷 Camera

There is no dedicated BSP API for camera functionality. Instead, the BSP provides default configuration macros:

• BSP_CAMERA_DEFAULT_CONFIG
• BSP_CAMERA_VFLIP
• BSP_CAMERA_HMIRROR

These macros are designed for use with the esp32-camera component.

Note

Don't forget to initialize I2C (bsp_i2c_init()) before using the camera, as some camera modules require I2C for configuration.

Example Usage

/* Initialize I2C bus (required by camera module) */
bsp_i2c_init();

/* Initialize the camera using BSP default config */
const camera_config_t camera_config = BSP_CAMERA_DEFAULT_CONFIG;
esp_camera_init(&camera_config);

/* Optional: Set camera orientation */
sensor_t *s = esp_camera_sensor_get();
s->set_vflip(s, BSP_CAMERA_VFLIP);     // Vertical flip
s->set_hmirror(s, BSP_CAMERA_HMIRROR); // Horizontal mirror

...

/* Capture a frame */
camera_fb_t * pic = esp_camera_fb_get();
if (pic) {
    /* Access raw image data in pic->buf with size pic->len */
    process_image(pic->buf, pic->len);  // Replace with your function
    esp_camera_fb_return(pic);
}

Camera API Reference

Macros

Type	Name
define	BSP_CAMERA_D0 (GPIO_NUM_39)
define	BSP_CAMERA_D1 (GPIO_NUM_40)
define	BSP_CAMERA_D2 (GPIO_NUM_41)
define	BSP_CAMERA_D3 (GPIO_NUM_42)
define	BSP_CAMERA_D4 (GPIO_NUM_15)
define	BSP_CAMERA_D5 (GPIO_NUM_16)
define	BSP_CAMERA_D6 (GPIO_NUM_48)
define	BSP_CAMERA_D7 (GPIO_NUM_47)
define	BSP_CAMERA_DEFAULT_CONFIG Camera default configuration.
define	BSP_CAMERA_HMIRROR 0
define	BSP_CAMERA_HSYNC (GPIO_NUM_38)
define	BSP_CAMERA_PCLK (GPIO_NUM_45)
define	BSP_CAMERA_VFLIP 0
define	BSP_CAMERA_VSYNC (GPIO_NUM_46)
define	BSP_CAMERA_XCLK (GPIO_NUM_NC)