LED Drivers

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LED Matrices

This example uses the WS2812 LED but applies to all matrices.

Tip

Needed NuGets: GHIElectronics.TinyCLR.Drivers.Worldsemi.WS2812, GHIElectronics.TinyCLR.Drivers.BasicGraphis

LedMatrix Class

class LedMatrix : BasicGraphics {
    private uint row, column;
    WS2812Controller leds;

    public LedMatrix(GpioPin pin, uint column, uint row) { 
        this.row = row;
        this.column = column;
        this.leds = new WS2812Controller(pin, this.row * this.column, WS2812Controller.DataFormat.rgb565);

        Clear();
    }

    public override void Clear() {
        leds.Clear();
    }

    public override void SetPixel(int x, int y, uint color) {
        if (x < 0 || x >= this.column) return;
        if (y < 0 || y >= this.row) return;

        // even columns are inverted
        if ((x & 0x01) != 0) {
            y = (int)(this.row - 1 - y);
        }

        var index = x * this.row + y;

        leds.SetColor((int)index, (byte)(color >> 16), (byte)(color >> 8), (byte)(color >> 0));
    }
    public void Flush() {
        leds.Flush();
    }
}

Use the LEDMatrix Class as shown

var pin = GpioController.GetDefault().OpenPin(SC20100.GpioPin.PC6);
var screen = new LedMatrix(pin, 8, 32);

screen.Clear();
var col = LedMatrix.ColorFromRgb(0, 20, 50);

var c = 0;
while (true){
    screen.Clear();
    screen.DrawString(c++.ToString(), col, 0, 0);
    screen.Flush();
    Thread.Sleep(10);
}

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WS2812

The WS2812 driver is implemented natively. It supports 565 and 888 color formats.

Note

These LEDs are commonly referred to as Neopixel

Tip

Needed NuGet: GHIElectronics.TinyCLR.Drivers.Worldsemi.WS2812

const int NUM_LED = 4; // 4 leds
var pin = GpioController.GetDefault().OpenPin(SC20260.GpioPin.PA0);
pin.SetDriveMode(GpioPinDriveMode.Output);
leds = new WS2812Controller(pin, NUM_LED, WS2812Controller.DataFormat.rgb888);
leds.SetColor(0, 0xFF, 0, 0); // red
leds.SetColor(1, 0, 0xFF, 0); // green
leds.SetColor(2, 0, 0, 0xFF); // blue
leds.SetColor(3, 0xFF, 0xFF, 0xFF); // white

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APA102C

Tip

Needed NuGet: GHIElectronics.TinyCLR.Drivers.ShijiLighting.APA102C

The APA102C is very similar to the Neopixel WS2812 except it uses standard 3 wire SPI, while the Neopixel uses a single wire and it's own proprietary format.

var cs = GpioController.GetDefault().OpenPin(SC20260.GpioPin.PE4);

var settings = new SpiConnectionSettings() {
    ChipSelectType = SpiChipSelectType.Gpio,
    ChipSelectLine = cs,
    Mode = SpiMode.Mode1,
    ClockFrequency = 4_000_000,
};

var spiBus = SpiController.FromName(SC20100.SpiBus.Spi4);
var led = new APA102CCController(spiBus, 24);

led.SetColor(1, 255, 0, 0); // 2nd LED is Red
led.Flush();

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LPD8806

Tip

Needed NuGet: GHIElectronics.TinyCLR.Drivers.GreeledElectronics.LPD8806

var cs = GpioController.GetDefault().OpenPin(SC20260.GpioPin.PE4);

var settings = new SpiConnectionSettings() {
    ChipSelectType = SpiChipSelectType.Gpio,
    ChipSelectLine = cs,
    Mode = SpiMode.Mode1,
    ClockFrequency = 4_000_000,
};

var spiBus = SpiController.FromName(SC20100.SpiBus.Spi4);
var led = new LPD8806Controller(spiBus, 24);

led.SetColor(1, 255, 0, 0); // 2nd LED is Red
led.Flush();