# go-rpi-rgb-led-matrix [](https://godoc.org/github.com/mcuadros/go-rpi-rgb-led-matrix) [](https://travis-ci.org/mcuadros/go-rpi-rgb-led-matrix)
Go binding for [`rpi-rgb-led-matrix`](https://github.com/hzeller/rpi-rgb-led-matrix) an excellent C++ library to control [RGB LED displays](https://learn.adafruit.com/32x16-32x32-rgb-led-matrix/overview) with Raspberry Pi GPIO.
This library includes the basic bindings to control de LED Matrix directly and also a convenient [ToolKit](https://godoc.org/github.com/mcuadros/go-rpi-rgb-led-matrix#ToolKit) with more high level functions. Also some [examples](https://github.com/mcuadros/go-rpi-rgb-led-matrix/tree/master/examples) are included to test the library and the configuration.
The [`Canvas`](https://godoc.org/github.com/mcuadros/go-rpi-rgb-led-matrix#Canvas) struct implements the [`image.Image`](https://golang.org/pkg/image/#Image) interface from the Go standard library. This makes the interaction with the matrix simple as work with a normal image in Go, allowing the usage of any Go library build around the `image.Image` interface.
To learn about the configuration and the wiring go to the [original library](https://github.com/hzeller/rpi-rgb-led-matrix), is highly detailed and well explained.
Installation
------------
The recommended way to install `go-rpi-rgb-led-matrix` is:
```sh
go get github.com/mcuadros/go-rpi-rgb-led-matrix
```
Then you will get an **expected** error like this:
```
# github.com/mcuadros/go-rpi-rgb-led-matrix
/usr/bin/ld: cannot find -lrgbmatrix
collect2: error: ld returned 1 exit status
```
This happens because you need to compile the `rgbmatrix` C bindings:
```sh
cd $GOPATH/src/github.com/mcuadros/go-rpi-rgb-led-matrix/vendor/rpi-rgb-led-matrix/
git submodule update --init
make
cd $GOPATH/src/github.com/mcuadros/go-rpi-rgb-led-matrix/
go install -v ./...
```
Examples
--------
Setting all the pixels to white:
```go
// create a new Matrix instance with the DefaultConfig
m, _ := rgbmatrix.NewRGBLedMatrix(&rgbmatrix.DefaultConfig)
// create the Canvas, implements the image.Image interface
c := rgbmatrix.NewCanvas(m)
defer c.Close() // don't forgot close the Matrix, if not your leds will remain on
// using the standard draw.Draw function we copy a white image onto the Canvas
draw.Draw(c, c.Bounds(), &image.Uniform{color.White}, image.ZP, draw.Src)
// don't forget call Render to display the new led status
c.Render()
```
Playing a GIF into your matrix during 30 seconds:
```go
// create a new Matrix instance with the DefaultConfig
m, _ := rgbmatrix.NewRGBLedMatrix(&rgbmatrix.DefaultConfig)
// create a ToolKit instance
tk := rgbmatrix.NewToolKit(m)
defer tk.Close() // don't forgot close the Matrix, if not your leds will remain on
// open the gif file for reading
file, _ := os.Open("mario.gif")
// play of the gif using the io.Reader
close, _ := tk.PlayGIF(f)
fatal(err)
// we wait 30 seconds and then we stop the playing gif sending a True to the returned chan
time.Sleep(time.Second * 30)
close <- true
```
The image of the header was recorded using this few lines, the running _Mario_ gif, and three 32x64 pannels.
Check the folder [`examples`](https://github.com/mcuadros/go-rpi-rgb-led-matrix/tree/master/examples) folder for more examples
Matrix Emulation
----------------
As part of the library an small Matrix emulator is provided. The emulator renderize a virtual RGB matrix on a window in your desktop, without needing a real RGB matrix connected to your computer.
To execute the emulator set the `MATRIX_EMULATOR` environment variable to `1`, then when `NewRGBLedMatrix` is used, a `emulator.Emulator` is returned instead of a interface the real board.
License
-------
MIT, see [LICENSE](LICENSE)