node-pixelpusher

Heroic Robotics' Pixel Pusher LED controller interface.

Install

npm install heroic-pixel-pusher

Using The Library :

Prepare To Push

var PixelPusher = require('heroic-pixel-pusher');

Discovering A PixelPusher On Your Network

new PixelPusher().on('discover', function(controller) {
    var timer = null;

    // log connection data on initial discovery
    console.log('-----------------------------------');
    console.log('Discovered PixelPusher on network: ');
    console.log(controller.params.pixelpusher);
    console.log('-----------------------------------');

    // capture the update message sent back from the pp controller
    controller.on('update', function() {
        console.log ({
            updatePeriod  : this.params.pixelpusher.updatePeriod,
            deltaSequence : this.params.pixelpusher.deltaSequence,
            powerTotal    : this.params.pixelpusher.powerTotal
        });
    }).on('timeout', function() {
        // be sure to handel the situation when the controller dissappears.
        // this could be due to power cycle or network conditions
        console.log('TIMEOUT : PixelPusher at address [' + controller.params.ipAddress + '] with MAC (' + controller.params.macAddress + ') has timed out. Awaiting re-discovery....');
        if (!!timer) clearInterval(timer);
    });

    //--
    // create a timer of some fps frequency and send the new pixel data
    //--

}).on('error', function(err) {
  console.log('PixelPusher Error: ' + err.message);
});

Pushing Pixels (push it real good!)

// aquire the number of strips that the controller has said it
// has connected via the pixel.rc config file
var NUM_STRIPS = controller.params.pixelpusher.numberStrips;

// aquire the number of pixels we that the controller reports is
// in each strip. This is set in the pixel.rc file placed on your thumb drive.
var PIXELS_PER_STRIP = controller.params.pixelpusher.pixelsPerStrip;

// create a loop that will send commands to the PP to update the strip
var UPDATE_FREQUENCY_MILLIS = 30;// 15 is just faster than 60 FPS

timer = setInterval(function() {
    // create an array to hold the data for all the strips at once
    // loop
    var strips = [];
    for (var stripId = 0; stripId< NUM_STRIPS; stripId ++){
        var s = new PixelStrip(stripId,PIXELS_PER_STRIP);
        // set a random pixel blue
        s.getRandomPixel().setColor(0,0,255, 0.1);
        // render the strip data into the correct format for sending
        // to the pixel pusher controller
        var renderedStripData = s.getStripData();
        // add this data to our list of strip data to send
        strips.push(renderedStripData);
    }
    // inform the controller of the new strip frame
    controller.refresh(strips);
}, UPDATE_FREQUENCY_MILLIS);

LED Data Formats

// if you are using NeoPixels from Adafruit you wont need to
// use this.

if (strip[x].flags & 0x1) {
    // red, green blue, orange[3], white[3]

    // indicates that the actual number of pixels is pixelsPerStrip/3,
    // each pixel is encoded as 9 octets
    //     first three octets are R, G, and B
    //     next three octets is the orange value (three times)
    //     next three octets is the white  value (three times)

} else if (strip[x].flags & 0x2) { // wide pixels
    // indicates that the actual number of pixels is pixelsPerStrip/2,
    // each pixel is encoded as 6 octets: R >> 8, G >> 8, B >> 8, R & 0xff, G & 0xff, B & 0xff
} else {
    // each pixel is encoded as three octets: R, G, and B
    // this is how the library handles data by default.
}