led_strip_spi: SPI-based driver for SK9822/APA102 LED strips

Defines

LED_STRIP_SPI_MAX_BRIGHTNESS

Maximum brightness value for a pixel.

Functions

esp_err_t led_strip_spi_install()

Setup the driver.

This method must be called before any other led_strip_spi methods

Returns:

ESP_OK on success

esp_err_t led_strip_spi_init(led_strip_spi_t *strip)

Initialize LED strip and allocate buffer memory.

Parameters:

strip – Descriptor of LED strip

Returns:

ESP_OK on success

esp_err_t led_strip_spi_free(led_strip_spi_t *strip)

Free LED strip.

Parameters:

strip – Descriptor of LED strip

Returns:

ESP_OK on success

esp_err_t led_strip_spi_flush(led_strip_spi_t *strip)

Send strip buffer to LEDs.

Parameters:

strip – Descriptor of LED strip

Returns:

ESP_OK on success

esp_err_t led_strip_spi_set_pixel(led_strip_spi_t *strip, const int num, const rgb_t color)

Set color of single LED in strip.

This function does not actually change colors of the LEDs. Call led_strip_spi_flush() to send buffer to the LEDs.

Parameters:

  • strip – Descriptor of LED strip

  • num – LED number, [0:strip.length - 1].

  • color – RGB color

Returns:

ESP_OK on success

esp_err_t led_strip_spi_set_pixel_brightness(led_strip_spi_t *strip, const int num, const rgb_t color, const uint8_t brightness)

Set color of single LED in strip.

This function does not actually change colors of the LEDs. Call led_strip_spi_flush() to send buffer to the LEDs.

Parameters:

  • strip – Descriptor of LED strip

  • num – LED number, [0:strip.length - 1].

  • color – RGB color

  • brightness – Brightness of the LED, [0:100].

Returns:

ESP_OK on success

esp_err_t led_strip_spi_set_pixels(led_strip_spi_t *strip, const int start, size_t len, const rgb_t data)

Set colors of multiple LEDs.

This function does not actually change colors of the LEDs. Call led_strip_spi_flush() to send buffer to the LEDs.

Parameters:

  • strip – Descriptor of LED strip

  • start – First LED index, 0-based

  • len – Number of LEDs

  • data – Pointer to RGB data

Returns:

ESP_OK on success

esp_err_t led_strip_spi_set_pixels_brightness(led_strip_spi_t *strip, const int start, size_t len, const rgb_t data, const uint8_t brightness)

Set colors of multiple LEDs.

This function does not actually change colors of the LEDs. Call led_strip_spi_flush() to send buffer to the LEDs.

Parameters:

  • strip – Descriptor of LED strip

  • start – First LED index, 0-based

  • len – Number of LEDs

  • data – Pointer to RGB data

  • brightness – Brightness of the LED, [0:100].

Returns:

ESP_OK on success

esp_err_t led_strip_spi_fill(led_strip_spi_t *strip, size_t start, size_t len, rgb_t color)

Set multiple LEDs to the one color.

This function does not actually change colors of the LEDs. Call led_strip_spi_flush() to send buffer to the LEDs.

Parameters:

  • strip – Descriptor of LED strip

  • start – First LED index, 0-based

  • len – Number of LEDs

  • color – RGB color

Returns:

ESP_OK on success

esp_err_t led_strip_spi_fill_brightness(led_strip_spi_t *strip, size_t start, size_t len, rgb_t color, const uint8_t brightness)

Set multiple LEDs to the one color.

This function does not actually change colors of the LEDs. Call led_strip_spi_flush() to send buffer to the LEDs.

Parameters:

  • strip – Descriptor of LED strip

  • start – First LED index, 0-based

  • len – Number of LEDs

  • color – RGB color

  • brightness – Brightness of the LEDs, [0:100].

Returns:

ESP_OK on success

Defines

LED_STRIP_SPI_DEFAULT_HOST_DEVICE

Default is SPI2_HOST (HSPI_HOST if esp-idf version is v3.x).

LED_STRIP_SPI_DEFAULT_MOSI_IO_NUM

GPIO pin number of LED_STRIP_SPI_DEFAULT_HOST_DEVICE’s MOSI (default is 13 for ESP32, 7 for ESP32C3)

LED_STRIP_SPI_DEFAULT_SCLK_IO_NUM

GPIO pin number of LED_STRIP_SPI_DEFAULT_HOST_DEVICE’s SCLK (default is 14 for ESP32, 6 for ESP32C3)

LED_STRIP_SPI_DEFAULT_DMA_CHAN

Default DMA channel to use.

Default is SPI_DMA_CH_AUTO for ESP-IDF v4.3 and newer, 1 for older versions.

LED_STRIP_SPI_DEFAULT_ESP32()

Macro to initialize led_strip_spi_esp32_t.

buf: NULL, length: 1, host_device: LED_STRIP_SPI_DEFAULT_HOST_DEVICE, mosi_io_num: LED_STRIP_SPI_DEFAULT_MOSI_IO_NUM, max_transfer_sz: 0, clock_speed_hz: 1000000, queue_size: 1, device_handle: NULL, dma_chan: 1

struct led_strip_spi_esp32_t
#include <led_strip_spi_esp32.h>

LED strip descriptor for ESP32-family.

Public Members

void *buf
size_t length
spi_host_device_t host_device
int mosi_io_num

GPIO number of SPI MOSI.

int sclk_io_num

GPIO number of SPI SCLK.

int max_transfer_sz

Maximum transfer size in bytes. Defaults to 4094 if 0.

int clock_speed_hz

Clock speed in Hz.

int queue_size

Queue size used by spi_device_queue_trans().

spi_device_handle_t device_handle

Device handle assigned by the driver. The caller must provdie this.

int dma_chan

DMA channed to use. Either 1 or 2.

spi_transaction_t transaction

SPI transaction used internally by the driver.

Defines

LED_STRIP_SPI_DEFAULT_ESP8266()

A macro to initialize led_strip_spi_esp8266_t.

length: 1 clk_div: SPI_2MHz_DIV

struct led_strip_spi_esp8266_t
#include <led_strip_spi_esp8266.h>

LED strip descriptor for ESP8266.

Public Members

void *buf

Pointer to the buffer.

size_t length

Number of pixels.

spi_clk_div_t clk_div

Value of clk_div, such as SPI_2MHz_DIV. See available values in ${IDF_PATH}/components/esp8266/include/driver/spi.h.

Defines

LED_STRIP_SPI_FRAME_SK9822_START_SIZE

The size in bytes of start frame.

LED_STRIP_SPI_FRAME_SK9822_LED_SIZE

The size in bytes of each LED frame.

LED_STRIP_SPI_FRAME_SK9822_LEDS_SIZE(N_PIXEL)

Total size in bytes of all LED frames in a strip. N_PIXEL is the number of pixels in the strip.

LED_STRIP_SPI_FRAME_SK9822_RESET_SIZE

The size in bytes of reset frame.

LED_STRIP_SPI_FRAME_SK9822_END_SIZE(N_PIXEL)

The size in bytes of the last frame. N_PIXEL is the number of pixels in the strip.

LED_STRIP_SPI_FRAME_SK9822_LED_MSB3

A magic number of [31:29] in LED frames. The bits must be 1 (APA102, SK9822)

LED_STRIP_SPI_FRAME_SK9822_LED_BRIGHTNESS_BITS

Number of bits used to describe the brightness of the LED.

LED_STRIP_SPI_BUFFER_SIZE(N_PIXEL)

A macro to caliculate required size of buffer. N_PIXEL is the number of pixels in the strip.

Functions

esp_err_t led_strip_spi_sk9822_buf_init(led_strip_spi_t *strip)

Initialize the buffer of SK9822 strip.

Parameters:

strip – [in] LED strip descriptor to initialize

Returns:

ESP_OK on success

esp_err_t led_strip_spi_set_pixel_sk9822(led_strip_spi_t *strip, size_t num, rgb_t color, uint8_t brightness)

Set color of a pixel of SK9822 strip.

Parameters:

  • strip – [in] LED strip descriptor.

  • num – [in] Index of the LED pixel (zero-based).

  • color – [in] The color to set.

  • brightness – [in] The brightness to set, [0:100].

Returns:

ESP_OK on success.