Configuration¶

The Kconfig options and constructor arguments that set a strip's pin, length, LED type, timing and brightness.

Kconfig¶

The component adds the menu HF-ESP32-WS2812-RMT Configuration to idf.py menuconfig. Its values are the defaults of the WS2812Strip constructor and the fixed settings of the C interface.

Option	Default	Meaning
`CONFIG_WS2812_LED_TYPE_RGB` / `_RGBW`	RGB	24 or 32 bits per LED
`CONFIG_WS2812_NUM_LEDS`	8	Number of LEDs
`CONFIG_WS2812_LED_RMT_TX_GPIO`	18	Data pin
`CONFIG_WS2812_LED_RMT_TX_CHANNEL`	-1	Unused: ESP-IDF chooses the channel
`CONFIG_WS2812_T0H`	4	0 bit high time, in 100 ns ticks (400 ns)
`CONFIG_WS2812_T1H`	8	1 bit high time, in 100 ns ticks (800 ns)
`CONFIG_WS2812_T0L`	9	0 bit low time, in 100 ns ticks (900 ns)
`CONFIG_WS2812_T1L`	5	1 bit low time, in 100 ns ticks (500 ns)
`CONFIG_WS2812_DEFAULT_BRIGHTNESS`	255	0 to 255

Every option is the default of the matching WS2812Strip constructor argument. The LED type, count, timing and brightness are also the fixed settings of the C interface.

The timing defaults are the WS2812B values in ticks of 100 ns. Version 1.0.0 and earlier defaulted to 14, 52, 52 and 52 (1.4 µs and 5.2 µs, read as all ones): a project sdkconfig written by an older version keeps those values, so delete the four lines from it or set them again. A typical sdkconfig.defaults:

sdkconfig.defaults

CONFIG_WS2812_T0H=4
CONFIG_WS2812_T1H=8
CONFIG_WS2812_T0L=9
CONFIG_WS2812_T1L=5
CONFIG_WS2812_LED_RMT_TX_GPIO=8
CONFIG_WS2812_NUM_LEDS=16

Constructor arguments¶

// WS2812B timing in 100 ns ticks: T0H 400 ns, T1H 800 ns, T0L 900 ns, T1L 500 ns (also the Kconfig
// defaults).
WS2812Strip make_status_strip() {
  return WS2812Strip(GPIO_NUM_8,   // data pin
                     -1,           // channel: unused, ESP-IDF picks a free one
                     16,           // LEDs
                     LedType::RGB, // 24 bits per LED (LedType::RGBW: 32)
                     4, 8, 9, 5,   // T0H, T1H, T0L, T1L in ticks
                     64);          // brightness 0-255
}

Argument	Default	Notes
`gpio` (`gpio_num_t`)	`CONFIG_WS2812_LED_RMT_TX_GPIO`	Any output-capable GPIO
`channel` (`int`)	`CONFIG_WS2812_LED_RMT_TX_CHANNEL`	Kept for compatibility; unused, because ESP-IDF v5's RMT driver has no way to request a channel number
`num_leds` (`uint32_t`)	`CONFIG_WS2812_NUM_LEDS`	Change later with `SetNumLeds()`
`type` (`LedType`)	`RGB`, or `RGBW` when Kconfig selects it	`RGBW` sends 32 bits per LED: green, red, blue, white
`t0h`, `t1h`, `t0l`, `t1l` (`uint16_t`)	`CONFIG_WS2812_T0H` ...	Ticks of 100 ns; change later with `SetTimings()`
`brightness` (`uint8_t`)	`CONFIG_WS2812_DEFAULT_BRIGHTNESS`	Change later with `SetBrightness()`

Timing values by LED¶

LED	`t0h, t1h, t0l, t1l`	Datasheet values (each ±150 ns)
WS2812B	`4, 8, 9, 5`	0.4, 0.8, 0.85, 0.45 µs
WS2812	`4, 7, 8, 6`	0.35, 0.7, 0.8, 0.6 µs
Others (SK6812, WS2813, clones)	Round each time to 100 ns	Their own datasheet

The WS2812B row also fits the WS2812's windows, so one setting covers both.

Next¶

API guide uses these settings task by task; Signal timing explains the ticks.