ws281x

README

go-rpi-ws281x

golang binding for rpi_ws281x, userspace Raspberry Pi PWM library for WS281X LEDs. Supports any Raspberry and WS2812, SK6812RGB and SK6812RGBW LEDs strips, this includes Unicorn pHAT and NeoPixels

This is a Fork of github.com/mcuadros/go-rpi-ws281x.

Installation

go get (recommended)

The recommended way to install go-rpi-ws281x is to first install rpi_ws281x on your system. Please follow the instructions given in their README.md.

go-rpi-ws281x will look for the library in the system folders "/usr/local/lib" and "/usr/local/include/ws2811".

Now download this package and add it to your go.mod file with:

go get github.com/DerLukas15/go-rpi-ws281x

git clone

If you want to clone this repository instead of using go get you can also run make build in the main folder to download and compile rpi_ws281x locally. However you will then need to supply a replace statement in your go.mod file pointing to your local copy.

Run make install-rpi_ws281x as root to install rpi_ws281x like you would in the recommended way.

Examples

// create a new canvas with the given width and height, and the config, in this
// case the configuration is for a Unicorn pHAT (8x4 pixels matrix) with the
// default configuration
c, _ := ws281x.NewCanvas(8, 4, &ws281x.DefaultConfig)


// initialize the canvas and the matrix
c.Initialize()

// since ws281x implements image.Image any function like draw.Draw from the std
// library may be used with it.
//
// now we copy a white image into the ws281x.Canvas, this turn on all the leds
// to white
draw.Draw(c, c.Bounds(), image.NewUniform(color.White), image.ZP, draw.Over)

// render and sleep to see the leds on
c.Render()
time.Sleep(time.Second * 5)

// don't forget close the canvas, if not you leds may remain on
c.Close()

Check the folder examples folder for more examples

License

MIT, see LICENSE

Documentation

Index

• Variables
• type Canvas
  • func NewCanvas(w, h int, config *HardwareConfig) (*Canvas, error)
  • func (c *Canvas) At(x, y int) color.Color
  • func (c *Canvas) Bounds() image.Rectangle
  • func (c *Canvas) Clear() error
  • func (c *Canvas) Close() error
  • func (c *Canvas) ColorModel() color.Model
  • func (c *Canvas) Initialize() error
  • func (c *Canvas) Render() error
  • func (c *Canvas) Set(x, y int, color color.Color)
• type HardwareConfig
• type Matrix
  • func NewWS281x(size int, config *HardwareConfig) (Matrix, error)
• type StripType
• type WS281x
  • func (c *WS281x) At(position int) color.Color
  • func (c *WS281x) Close() error
  • func (c *WS281x) Initialize() error
  • func (c *WS281x) Render() error
  • func (c *WS281x) Set(position int, color color.Color)

Variables

var DefaultConfig = HardwareConfig{
	Pin:        18,
	Frequency:  800000,
	DMA:        10,
	Brightness: 30,
	StripType:  StripGRB,
}

DefaultConfig default WS281x configuration

Types

type Canvas

type Canvas struct {
	// contains filtered or unexported fields
}

Canvas is a image.Image representation of a WS281x matrix, it implements image.Image interface and can be used with draw.Draw for example

func NewCanvas

func NewCanvas(w, h int, config *HardwareConfig) (*Canvas, error)

NewCanvas returns a new Canvas using the given width and height and creates a new WS281x matrix using the given config

func (*Canvas) At

func (c *Canvas) At(x, y int) color.Color

At returns the color of the pixel at (x, y)

func (*Canvas) Bounds

func (c *Canvas) Bounds() image.Rectangle

Bounds return the topology of the Canvas

func (*Canvas) Clear

func (c *Canvas) Clear() error

Clear set all the leds on the matrix with color.Black

func (*Canvas) Close

func (c *Canvas) Close() error

Close clears the matrix and close the matrix

func (*Canvas) ColorModel

func (c *Canvas) ColorModel() color.Model

ColorModel returns the canvas' color model, always color.RGBAModel

func (*Canvas) Initialize

func (c *Canvas) Initialize() error

Initialize initialize the matrix and the canvas

func (*Canvas) Render

func (c *Canvas) Render() error

Render update the display with the data from the LED buffer

func (*Canvas) Set

func (c *Canvas) Set(x, y int, color color.Color)

Set set LED at position x,y to the provided 24-bit color value

type HardwareConfig

type HardwareConfig struct {
	Pin        int       // GPIO Pin with PWM alternate function, 0 if unused
	Frequency  int       // the frequency of the display signal in hertz, can go as low as 400000
	DMA        int       // the DMA channel to use
	Invert     bool      // specifying if the signal line should be inverted
	Channel    int       // PWM channel to us
	Brightness int       // brightness value between 0 and 255
	StripType  StripType // strip color layout
}

HardwareConfig WS281x configuration

type Matrix

type Matrix interface {
	Initialize() error
	At(position int) color.Color
	Set(position int, c color.Color)
	Render() error
	Close() error
}

func NewWS281x

func NewWS281x(size int, config *HardwareConfig) (Matrix, error)

NewWS281x returns a new matrix using the given size and config

type StripType

type StripType int

StripType layout

const (
	// 4 color R, G, B and W ordering
	StripRGBW StripType = 0x18100800
	StripRBGW StripType = 0x18100008
	StripGRBW StripType = 0x18081000
	StripGBRW StripType = 0x18080010
	StripBRGW StripType = 0x18001008
	StripBGRW StripType = 0x18000810

	// 3 color R, G and B ordering
	StripRGB StripType = 0x00100800
	StripRBG StripType = 0x00100008
	StripGRB StripType = 0x00081000
	StripGBR StripType = 0x00080010
	StripBRG StripType = 0x00001008
	StripBGR StripType = 0x00000810
)

type WS281x

type WS281x struct {
	Config *HardwareConfig
	// contains filtered or unexported fields
}

WS281x matrix representation for ws281x

func (*WS281x) At

func (c *WS281x) At(position int) color.Color

At return an Color which allows access to the LED display data as if it were a sequence of 24-bit RGB values.

func (*WS281x) Close

func (c *WS281x) Close() error

Close finalizes the ws281x interface

func (*WS281x) Initialize

func (c *WS281x) Initialize() error

Initialize initialize library, must be called once before other functions are called.

func (*WS281x) Render

func (c *WS281x) Render() error

Render update the display with the data from the LED buffer

func (*WS281x) Set

func (c *WS281x) Set(position int, color color.Color)

Set set LED at position x,y to the provided 24-bit color value.