obniz/parts/Light/WS2811/index.js

obniz sdk for javascript

class WS2811 {
  constructor() {
    this.keys = ['din', 'vcc', 'gnd'];
    this.requiredKeys = ['din'];
  }

  static info() {
    return {
      name: 'WS2811',
    };
  }

  wired(obniz) {
    this.obniz = obniz;

    obniz.setVccGnd(this.params.vcc, this.params.gnd, '5v');

    this.params.mode = 'master';
    this.params.frequency = 2 * 1000 * 1000;
    this.params.mosi = this.params.din;
    this.params.drive = '5v'; // It over spec for frequency. But VIN-HI require 0.7VCC<=.
    this.spi = this.obniz.getSpiWithConfig(this.params);
  }

  static _generateFromByte(val) {
    // T0H 0.5us+-0.15us
    // T1H 1.2us+-0.15us
    // T0L 2.0us+-0.15us
    // T1L 1.3us+-0.15us

    val = parseInt(val);
    const zero = 0x8;
    const one = 0xe;
    let ret = [];
    for (let i = 0; i < 8; i += 2) {
      let byte = 0;
      if (val & (0x80 >> i)) {
        byte = one << 4;
      } else {
        byte = zero << 4;
      }
      if (val & (0x80 >> (i + 1))) {
        byte |= one;
      } else {
        byte |= zero;
      }
      ret.push(byte);
    }
    return ret;
  }

  static _generateColor(r, g, b) {
    let array = WS2811._generateFromByte(r);
    array = array.concat(WS2811._generateFromByte(g));
    array = array.concat(WS2811._generateFromByte(b));
    return array;
  }

  static _generateHsvColor(h, s, v) {
    let C = v * s;
    let Hp = h / 60;
    let X = C * (1 - Math.abs((Hp % 2) - 1));

    let R, G, B;
    if (0 <= Hp && Hp < 1) {
      [R, G, B] = [C, X, 0];
    }
    if (1 <= Hp && Hp < 2) {
      [R, G, B] = [X, C, 0];
    }
    if (2 <= Hp && Hp < 3) {
      [R, G, B] = [0, C, X];
    }
    if (3 <= Hp && Hp < 4) {
      [R, G, B] = [0, X, C];
    }
    if (4 <= Hp && Hp < 5) {
      [R, G, B] = [X, 0, C];
    }
    if (5 <= Hp && Hp < 6) {
      [R, G, B] = [C, 0, X];
    }

    let m = v - C;
    [R, G, B] = [R + m, G + m, B + m];

    R = Math.floor(R * 255);
    G = Math.floor(G * 255);
    B = Math.floor(B * 255);

    let array = WS2811._generateFromByte(R);
    array = array.concat(WS2811._generateFromByte(G));
    array = array.concat(WS2811._generateFromByte(B));
    return array;
  }

  rgb(r, g, b) {
    this.spi.write(WS2811._generateColor(r, g, b));
  }

  hsv(h, s, v) {
    this.spi.write(WS2811._generateHsvColor(h, s, v));
  }

  rgbs(array) {
    let bytes = [];
    for (let i = 0; i < array.length; i++) {
      const oneArray = array[i];
      bytes = bytes.concat(
        WS2811._generateColor(oneArray[0], oneArray[1], oneArray[2])
      );
    }
    this.spi.write(bytes);
  }

  hsvs(array) {
    let bytes = [];
    for (let i = 0; i < array.length; i++) {
      const oneArray = array[i];
      bytes = bytes.concat(
        WS2811._generateHsvColor(oneArray[0], oneArray[1], oneArray[2])
      );
    }
    this.spi.write(bytes);
  }
}

if (typeof module === 'object') {
  module.exports = WS2811;
}