lpd8806-async/lib/LPD8806.js

Non-blocking LPD8806 NodeJS general library

/* MIT license */

var SPI = require('spi'),
    Color = require("color");

var ledCount = 32,
    device = '/dev/spidev0.0',
    ChannelOrder = {
        "RGB" : [0,1,2], // Probably not used, here for clarity
        "GRB" : [1,0,2], // Strands from Adafruit and some others (default)
        "BRG" : [1,2,0]  // Strands from many other manufacturers
    },
    c_order = ChannelOrder.GRB,
    masterBrightness = 1.0,
    buffer = [],
    gamma = new Buffer(256);
    

var LPD8806 = function(leds, dev, options){
    options = options || {};
    ledCount = leds || ledCount;
    device = dev || device;

    this.spi = new SPI.Spi(device, options, function(s){
      s.open();
    });

    for(var i = 0; i < ledCount; i++){
        buffer[i] = new Buffer([0x80, 0x80, 0x80]);
    }

    for(var g = 0; g < gamma.length; g++){
        gamma[g] = 0x80 | Math.floor( Math.pow(g/255, 2.5) * 127 + 0.5);
    }

    //Initialize the Complete RGB LED Strip
    this.update();
};

var __set_internal = function(pixel, color){
    if(pixel < 0 || pixel > this.lastIndex){
        throw 'dont go out of bounds';
    }
    buffer[pixel][c_order[0]] = gamma[~~(color.red() * masterBrightness)];
    buffer[pixel][c_order[1]] = gamma[~~(color.green() * masterBrightness)];
    buffer[pixel][c_order[2]] = gamma[~~(color.blue() * masterBrightness)];
};

LPD8806.prototype.setMasterBrightness = function(bright){
    if(bright > 1.0 || bright < 0.0){
        throw 'Brightness must be between 0.0 and 1.0';
    }
    masterBrightness = bright;
};

LPD8806.prototype.setChannelOrder = function(order){
    c_order = order;
};

LPD8806.prototype.updateBrightness = function(bright){
    if(bright > 1.0 || bright < 0.0){
        throw 'Brightness must be between 0.0 and 1.0';
    }
    masterBrightness = bright;
    for(var n = 0; n < buffer.length; n++){
        buffer[n][0] = gamma[~~(((buffer[n][0] > 128) ? buffer[n][0]: 0) * masterBrightness)];
        buffer[n][1] = gamma[~~(((buffer[n][1] > 128) ? buffer[n][1]: 0) * masterBrightness)];
        buffer[n][2] = gamma[~~(((buffer[n][2] > 128) ? buffer[n][2]: 0) * masterBrightness)];
    }
    //Update the Stip after Updating the Buffer
    this.update();
};

LPD8806.prototype.update = function(){
    var _buffer = buffer.slice(0, buffer.length);
    _buffer.push(new Buffer([0x00, 0x00, 0x00]));
    _buffer.push(new Buffer([0x00]));
    this.spi.write(Buffer.concat(_buffer));
};


LPD8806.prototype.fill = function(color){
    var pixel = ledCount;
    while(pixel--){
        __set_internal(pixel, color);
    }
    //Update the Stip after Updating the Buffer
    this.update();
};

LPD8806.prototype.fillRGB = function(r, g, b){
    var pixel = ledCount;
    while(pixel--){
        __set_internal(pixel, Color({r: r, g: g, b: b}));
    }
    //Update the Stip after Updating the Buffer
    this.update();
};

LPD8806.prototype.fillHSV = function(h, s, v){
    var pixel = ledCount;
    while(pixel--){
        __set_internal(pixel, Color({h: h, s: s, v:v}));
    }
    //Update the Stip after Updating the Buffer
    this.update();
};

LPD8806.prototype.allOFF = function(){
    var pixel = ledCount;
    while(pixel--){
        __set_internal(pixel, Color({r:0 , g: 0, b: 0}));
    }
    //Update the Stip after Updating the Buffer
    this.update();
};

LPD8806.prototype.setPixel = function(pixel, color){
    __set_internal(pixel, color);
};

LPD8806.prototype.setPixelRGB = function(pixel, r, g, b){
    __set_internal(pixel, Color({r: r, g: g, b: b}));
};

LPD8806.prototype.setPixelHSV = function(pixel, h, s, v){
    __set_internal(pixel, Color({h: h, s: s, v:v}));
};

LPD8806.prototype.setPixelOff = function(pixel){
    __set_internal(pixel, Color({r:0 , g: 0, b: 0}));
};

LPD8806.prototype.wheel_color = function(wheelpos){
    var r,g,b;
    if (wheelpos < 0){
        wheelpos = 0;
    }
    if (wheelpos > 384){
        wheelpos = 384;
    }

    if (wheelpos < 128){
        r = 127 - wheelpos % 128;
        g = wheelpos % 128;
        b = 0;
    } else if (wheelpos < 256){
        g = 127 - wheelpos % 128;
        b = wheelpos % 128;
        r = 0;
    } else {
        b = 127 - wheelpos % 128;
        r = wheelpos % 128;
        g = 0;
    }
    return new Color({r: r, g: g, b: b});
};

module.exports = LPD8806;