lights_sample

This project contains simple programs for NeoPixels running from the Fadecandy microcontroller.

Writing simple pixel programs

Here is a simple Java program that will color some of the lights:

    public static void main(String[] args) throws Exception {
        OpcClient server = new OpcClient("10.28.46.61", 7890);
        OpcDevice fadecandy = server.addDevice();
        PixelStrip strip = fadecandy.addPixelStrip(0, 64);

        int color = 0xFF0000;  // red
        strip.setPixelColor(3, color);
        strip.setPixelColor(5, 0x888800); // yellow
        strip.setPixelColor(7, 0x00FF00); // green

        server.show();        // Display the pixel changes
        Thread.sleep(5000);   // Wait five seconds
        server.clear();       // Set all pixels to black
        server .show();       // Show the darkened pixels

        server.close();
    }

Animations

We can also create Animation classes which will draw different patterns over and over. We can attach animations to any given pixel strip. When we attach a new animation object, the light patterns will change.

public class RandomPixels extends Animation {

    java.util.Random rand;

    public void reset(PixelStrip strip) {
        rand = new java.util.Random();
    }

    public boolean draw(PixelStrip strip) {
        int randomPixel = rand.nextInt(strip.getPixelCount());
        int randomColor = makeColor(rand.nextInt(255),
                         rand.nextInt(255), rand.nextInt(255));
        strip.setPixelColor(randomPixel, randomColor);
        return true;
    }
}

Server Configuration

The Fadecandy has eight pins, each of which can control a strip of 64 pixels. If you have contiguous strips of pixels starting on pin zero, then your fc_server won't need to map the output pixels numbers to configurable OPC numbers. However, if you have shorter strips connected to different pins, you may want to set up a JSON configuration file for the server. The OpcClient class can print out a JSON configuration based on strip definitions:

public static void main(String[] arg)  {
    OpcClient server = new OpcClient("127.0.0.1", 7980);
    OpcDevice fadeCandy = server.addDevice();

    PixelStrip strip1 = fadeCandy.addPixelStrip(0, 64);  // 8 x 8 grid on pin 0
    PixelStrip strip2 = fadeCandy.addPixelStrip(1, 8);   // 8 pixel strip on pin 1
    PixelStrip strip3 = fadeCandy.addPixelStrip(2, 16);  // 16 pixel ring on pin 2

    // Since the pixels are not uniform strips of 64, customize
    // the server config JSON file with the following:
    System.out.println(server.getConfig());
}