README
¶
go-rpi-rgb-led-matrix 
Go binding for rpi-rgb-led-matrix an excellent C++ library to control RGB LED displays with Raspberry Pi GPIO.
This library includes the basic bindings to control de LED Matrix directly and also a convenient ToolKit with more high level functions.
The Canvas struct implements the 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, is highly detailed and well explained.
Installation
This library is meant to be included in your project as a vendored dependency.
The go mod vendor command will not work for this purpose as it excludes the
lib/ directory containing the required C++ library.
It is recommended to use a tool like vend instead.
The C++ library must be built with:
cd vendor/github.com/jcrd/go-rpi-rgb-led-matrix/
make
Examples
Setting all the pixels to white:
// 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:
// 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.
License
MIT, see LICENSE
Documentation
¶
Index ¶
- Variables
- type Animation
- type Canvas
- type HardwareConfig
- type Matrix
- type RGBLedMatrix
- func (c *RGBLedMatrix) Apply(leds []color.Color) error
- func (c *RGBLedMatrix) At(position int) color.Color
- func (c *RGBLedMatrix) Close() error
- func (c *RGBLedMatrix) Geometry() (width, height int)
- func (c *RGBLedMatrix) Initialize() error
- func (c *RGBLedMatrix) Render() error
- func (c *RGBLedMatrix) Set(position int, color color.Color)
- type ScanMode
- type ToolKit
- func (tk *ToolKit) Close() error
- func (tk *ToolKit) PlayAnimation(a Animation) error
- func (tk *ToolKit) PlayGIF(r io.Reader) (chan bool, error)
- func (tk *ToolKit) PlayImage(i image.Image, delay time.Duration) error
- func (tk *ToolKit) PlayImageUntil(i image.Image, notify <-chan time.Time) error
- func (tk *ToolKit) PlayImages(images []image.Image, delay []time.Duration, loop int) chan bool
Constants ¶
This section is empty.
Variables ¶
var DefaultConfig = HardwareConfig{ Rows: 32, Cols: 32, ChainLength: 1, Parallel: 1, PWMBits: 11, PWMLSBNanoseconds: 130, Brightness: 100, ScanMode: Progressive, }
DefaultConfig default WS281x configuration
Functions ¶
This section is empty.
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 ¶
NewCanvas returns a new Canvas using the given width and height and creates a new WS281x matrix using the given config
func (*Canvas) ColorModel ¶
ColorModel returns the canvas' color model, always color.RGBAModel
type HardwareConfig ¶
type HardwareConfig struct {
// Rows the number of rows supported by the display, so 32 or 16.
Rows int
// Cols the number of columns supported by the display, so 32 or 64 .
Cols int
// ChainLengthis the number of displays daisy-chained together
// (output of one connected to input of next).
ChainLength int
// Parallel is the number of parallel chains connected to the Pi; in old Pis
// with 26 GPIO pins, that is 1, in newer Pis with 40 interfaces pins, that
// can also be 2 or 3. The effective number of pixels in vertical direction is
// then thus rows * parallel.
Parallel int
// Set PWM bits used for output. Default is 11, but if you only deal with
// limited comic-colors, 1 might be sufficient. Lower require less CPU and
// increases refresh-rate.
PWMBits int
// Change the base time-unit for the on-time in the lowest significant bit in
// nanoseconds. Higher numbers provide better quality (more accurate color,
// less ghosting), but have a negative impact on the frame rate.
PWMLSBNanoseconds int // the DMA channel to use
// Brightness is the initial brightness of the panel in percent. Valid range
// is 1..100
Brightness int
// ScanMode progressive or interlaced
ScanMode ScanMode // strip color layout
// Disable the PWM hardware subsystem to create pulses. Typically, you don't
// want to disable hardware pulsing, this is mostly for debugging and figuring
// out if there is interference with the sound system.
// This won't do anything if output enable is not connected to GPIO 18 in
// non-standard wirings.
DisableHardwarePulsing bool
ShowRefreshRate bool
InverseColors bool
// Name of GPIO mapping used
HardwareMapping string
}
HardwareConfig rgb-led-matrix configuration
type Matrix ¶
type Matrix interface {
Geometry() (width, height int)
At(position int) color.Color
Set(position int, c color.Color)
Apply([]color.Color) error
Render() error
Close() error
}
Matrix is an interface that represent any RGB matrix, very useful for testing
func NewRGBLedMatrix ¶
func NewRGBLedMatrix(config *HardwareConfig) (c Matrix, err error)
NewRGBLedMatrix returns a new matrix using the given size and config
type RGBLedMatrix ¶
type RGBLedMatrix struct {
Config *HardwareConfig
// contains filtered or unexported fields
}
RGBLedMatrix matrix representation for ws281x
func (*RGBLedMatrix) Apply ¶
func (c *RGBLedMatrix) Apply(leds []color.Color) error
Apply set all the pixels to the values contained in leds
func (*RGBLedMatrix) At ¶
func (c *RGBLedMatrix) 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 (*RGBLedMatrix) Close ¶
func (c *RGBLedMatrix) Close() error
Close finalizes the ws281x interface
func (*RGBLedMatrix) Geometry ¶
func (c *RGBLedMatrix) Geometry() (width, height int)
Geometry returns the width and the height of the matrix
func (*RGBLedMatrix) Initialize ¶
func (c *RGBLedMatrix) Initialize() error
Initialize initialize library, must be called once before other functions are called.
func (*RGBLedMatrix) Render ¶
func (c *RGBLedMatrix) Render() error
Render update the display with the data from the LED buffer
type ToolKit ¶
type ToolKit struct {
// Canvas is the Canvas wrapping the Matrix, if you want to instanciate
// a ToolKit with a custom Canvas you can use directly the struct,
// without calling NewToolKit
Canvas *Canvas
// Transform function if present is applied just before draw the image to
// the Matrix, this is a small example:
// tk.Transform = func(img image.Image) *image.NRGBA {
// return imaging.Fill(img, 64, 96, imaging.Center, imaging.Lanczos)
// }
Transform func(img image.Image) *image.NRGBA
}
ToolKit is a convinient set of function to operate with a led of Matrix
func NewToolKit ¶
NewToolKit returns a new ToolKit wrapping the given Matrix
func (*ToolKit) PlayAnimation ¶
PlayAnimation play the image during the delay returned by Next, until an err is returned, if io.EOF is returned, PlayAnimation finish without an error
func (*ToolKit) PlayGIF ¶
PlayGIF reads and draw a gif file from r. It use the contained images and delays and loops over it, until a true is sent to the returned chan
func (*ToolKit) PlayImageUntil ¶
PlayImageUntil draws the given image until is notified to stop
func (*ToolKit) PlayImages ¶
PlayImages draws a sequence of images during the given delays, the len of images should be equal to the len of delay. If loop is true the function loops over images until a true is sent to the returned chan
Source Files