ws2812_control.h File Reference

ESP-IDF RMT backend for WS2812 / NeoPixel LED chains. More...

#include "driver/gpio.h"
#include "driver/rmt_tx.h"
#include "driver/rmt_types.h"
#include "esp_err.h"
#include "led_strip_encoder.h"
#include "sdkconfig.h"
#include "ws2812_rmt_caps.h"
#include <stdint.h>

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Classes
struct	led_state
	Desired colors for a chain of LEDs. More...

Macros
Driver constants
#define	NUM_LEDS   CONFIG_WS2812_NUM_LEDS
#define	WS2812_BITS_PER_LED   24
#define	WS2812_LED_BUFFER_ITEMS   (NUM_LEDS * WS2812_BITS_PER_LED)
#define	WS2812_T0H   CONFIG_WS2812_T0H
#define	WS2812_T1H   CONFIG_WS2812_T1H
#define	WS2812_T0L   CONFIG_WS2812_T0L
#define	WS2812_T1L   CONFIG_WS2812_T1L
#define	WS2812_DEFAULT_BRIGHTNESS   CONFIG_WS2812_DEFAULT_BRIGHTNESS

Functions
esp_err_t	ws2812_control_init (gpio_num_t gpio_num, int channel)
	Initialise the RMT peripheral for WS2812 output.
esp_err_t	ws2812_write_leds (struct led_state new_state)
	Send LED colour data.
void	ws2812_set_brightness (uint8_t brightness)
	Set global brightness for subsequent transmissions.

Detailed Description

ESP-IDF RMT backend for WS2812 / NeoPixel LED chains.

This is not a portable CRTP chip driver. Public headers include ESP-IDF (driver/rmt_*.h, sdkconfig.h). Hosts that are not ESP32 do not compile this tree.

Copyright

Copyright (c) 2024-2025 HardFOC. All rights reserved.

Macro Definition Documentation

NUM_LEDS

#define NUM_LEDS   CONFIG_WS2812_NUM_LEDS

Number of LEDs that will be driven by the component.

WS2812_BITS_PER_LED

#define WS2812_BITS_PER_LED   24

WS2812_DEFAULT_BRIGHTNESS

#define WS2812_DEFAULT_BRIGHTNESS   CONFIG_WS2812_DEFAULT_BRIGHTNESS

Default global brightness scaling

WS2812_LED_BUFFER_ITEMS

#define WS2812_LED_BUFFER_ITEMS   (NUM_LEDS * WS2812_BITS_PER_LED)

Number of RMT items required to represent the LED chain.

WS2812_T0H

#define WS2812_T0H   CONFIG_WS2812_T0H

Timing for a '0' bit high pulse in RMT ticks

WS2812_T0L

#define WS2812_T0L   CONFIG_WS2812_T0L

Low time for any bit in RMT ticks

WS2812_T1H

#define WS2812_T1H   CONFIG_WS2812_T1H

Timing for a '1' bit high pulse in RMT ticks

WS2812_T1L

#define WS2812_T1L   CONFIG_WS2812_T1L

Function Documentation

ws2812_control_init()

esp_err_t ws2812_control_init	(	gpio_num_t	gpio_num,
		int	channel
	)

Initialise the RMT peripheral for WS2812 output.

This function must be called once before any LED data is transmitted. On failure everything it allocated is released, so it can be called again.

Parameters

gpio_num	GPIO connected to the LED strip.
channel	Unused: ESP-IDF v5's RMT driver picks a free channel itself.

Returns

ESP_OK on success, ESP_ERR_INVALID_STATE if already initialised, or an error code from the ESP-IDF drivers.

ws2812_set_brightness()

void ws2812_set_brightness

(

uint8_t

brightness

)

Set global brightness for subsequent transmissions.

All LED values are scaled by this factor before being sent. 255 means full brightness.

Parameters

brightness

Brightness level 0-255.

ws2812_write_leds()

esp_err_t ws2812_write_leds

(

struct led_state

new_state

)

Send LED colour data.

Sends every LED's colour (green, red, blue[, white], scaled by the brightness) with the Kconfig bit timing, then the reset code that latches the frame. Blocks the calling task until the frame has been transmitted.

Parameters

new_state

Desired LED colours.

Returns

ESP_OK on success, ESP_ERR_INVALID_STATE before ws2812_control_init(), or an ESP-IDF error code.