WS2812Strip Class Reference

C++ convenience wrapper for a chain of WS2812 LEDs. More...

#include <ws2812_cpp.hpp>

Public Member Functions
	WS2812Strip (gpio_num_t gpio=(gpio_num_t) CONFIG_WS2812_LED_RMT_TX_GPIO, int channel=CONFIG_WS2812_LED_RMT_TX_CHANNEL, uint32_t num_leds=NUM_LEDS, LedType type=LedType::RGB, uint16_t t0h=WS2812_T0H, uint16_t t1h=WS2812_T1H, uint16_t t0l=WS2812_T0L, uint16_t t1l=WS2812_T1L, uint8_t brightness=WS2812_DEFAULT_BRIGHTNESS)
	Construct a strip object.
esp_err_t	Begin ()
	Report whether the strip's RMT channel is ready, retrying its set-up if it failed.
void	SetPixel (uint32_t index, uint32_t rgbw)
	Set the colour of a single LED.
uint32_t	Length () const
esp_err_t	Show ()
	Send the currently stored colours to the LED strip.
void	SetBrightness (uint8_t value)
	Set global brightness for the strip.
void	SetNumLeds (uint32_t num_leds)
	Resize the strip to a new LED count at runtime.
void	SetTimings (uint16_t t0h, uint16_t t1h, uint16_t t0l, uint16_t t1l)
	Update the bit timing parameters.

Static Public Member Functions
static uint32_t	ColorWheel (uint8_t pos)
	Generate a colour from a 0-255 position on a colour wheel.
static constexpr const char *	GetDriverVersion () noexcept
	Get the compiled driver version string.
static constexpr uint8_t	GetDriverVersionMajor () noexcept
	Get the compiled driver major version number.
static constexpr uint8_t	GetDriverVersionMinor () noexcept
	Get the compiled driver minor version number.
static constexpr uint8_t	GetDriverVersionPatch () noexcept
	Get the compiled driver patch version number.

Static Public Attributes
static constexpr uint32_t	kResetTimeUs = 300

Detailed Description

C++ convenience wrapper for a chain of WS2812 LEDs.

All configuration such as GPIO, channel, LED type and timing can be supplied at runtime via the constructor, allowing multiple strips with different settings.

Constructor & Destructor Documentation

WS2812Strip()

WS2812Strip::WS2812Strip ( gpio_num_t  gpio = (gpio_num_t)CONFIG_WS2812_LED_RMT_TX_GPIO, int  channel = CONFIG_WS2812_LED_RMT_TX_CHANNEL, uint32_t  num_leds = NUM_LEDS, LedType  type = LedType::RGB, uint16_t  t0h = WS2812_T0H, uint16_t  t1h = WS2812_T1H, uint16_t  t0l = WS2812_T0L, uint16_t  t1l = WS2812_T1L, uint8_t  brightness = WS2812_DEFAULT_BRIGHTNESS  )

explicit

Construct a strip object.

Parameters

gpio	Output pin connected to the LEDs.
channel	RMT channel for signal generation.

Member Function Documentation

Begin()

esp_err_t WS2812Strip::Begin

(

)

Report whether the strip's RMT channel is ready, retrying its set-up if it failed.

The constructor already creates the channel; it no longer aborts when that fails. Call Begin() and check the result before the first Show().

Returns

ESP_OK when the channel is ready, otherwise the ESP-IDF error (for example ESP_ERR_NOT_FOUND when no RMT transmit channel is free).

ColorWheel()

uint32_t WS2812Strip::ColorWheel ( uint8_t  pos )

static

Generate a colour from a 0-255 position on a colour wheel.

Parameters

pos	Position on the colour wheel.

Returns

Packed RGB colour.

GetDriverVersion()

static constexpr const char * WS2812Strip::GetDriverVersion ( )

inlinestaticconstexprnoexcept

Get the compiled driver version string.

GetDriverVersionMajor()

static constexpr uint8_t WS2812Strip::GetDriverVersionMajor ( )

inlinestaticconstexprnoexcept

Get the compiled driver major version number.

GetDriverVersionMinor()

static constexpr uint8_t WS2812Strip::GetDriverVersionMinor ( )

inlinestaticconstexprnoexcept

Get the compiled driver minor version number.

GetDriverVersionPatch()

static constexpr uint8_t WS2812Strip::GetDriverVersionPatch ( )

inlinestaticconstexprnoexcept

Get the compiled driver patch version number.

Length()

uint32_t WS2812Strip::Length

(

)

const

Get the number of LEDs managed by this strip.

SetBrightness()

void WS2812Strip::SetBrightness

(

uint8_t

value

)

Set global brightness for the strip.

Parameters

value

Brightness 0-255.

SetNumLeds()

void WS2812Strip::SetNumLeds

(

uint32_t

num_leds

)

Resize the strip to a new LED count at runtime.

Clears all pixel data to zero. The RMT symbol buffer is resized to match the new LED count and current colour encoding.

Parameters

num_leds

New number of LEDs in the strip.

SetPixel()

void WS2812Strip::SetPixel	(	uint32_t	index,
		uint32_t	rgbw
	)

Set the colour of a single LED.

Parameters

index	Index of the LED starting from 0.
rgbw	Packed colour: 0xRRGGBB, or 0xWWRRGGBB on an RGBW strip. Show() sends it in the order the LED reads it (green, red, blue, then white).

SetTimings()

void WS2812Strip::SetTimings	(	uint16_t	t0h,
		uint16_t	t1h,
		uint16_t	t0l,
		uint16_t	t1l
	)

Update the bit timing parameters.

Allows adjustment of the WS2812 protocol timings after construction.

Show()

esp_err_t WS2812Strip::Show

(

)

Send the currently stored colours to the LED strip.

Sends every pixel green, red, blue (then white), followed by a reset (line low for kResetTimeUs) that latches the frame. Blocks until the frame is on the wire.

Member Data Documentation

kResetTimeUs

constexpr uint32_t WS2812Strip::kResetTimeUs = 300

staticconstexpr

Length of the reset (latch) pulse that ends every frame: at least 280 us (WS2812B-V5).

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The documentation for this class was generated from the following files:

• inc/ws2812_cpp.hpp
• src/ws2812_cpp.cpp