watercooler.js

SPI2.setup({baud:3200000,mosi:B15});

var count = 150;
var pixels = new Uint8Array(count * 3);
function update() {
  SPI2.send4bit(pixels, 0b0001, 0b0011);
}
function dampen(p) {
  var i = (p % count) * 3;
  pixels[i]>>>=1;
  pixels[++i]>>>=1;
  pixels[++i]>>>=1;
  pixels[++i]>>>=1;
}
function rgb(p, r, g, b, w) {
  var i = (p % count) * 3;
  pixels[i] = g;
  pixels[++i] = r;
  pixels[++i] = b;
//  pixels[++i] = w;
}
function hue(p, h, d) {
  h = (h + count) % 768;
  d = d || 0;
  if (h < 256) return rgb(p, h >> d, (255-h) >> d, 0, 0);
  if (h < 512) return rgb(p, (511-h)>>d,0,(h-256)>>d, 0);
  return rgb(p, 0, (h-512)>>d, (767-h)>>d, 0);
}
function rand(x) {
  return Math.floor(Math.random() * x);
}


var h = 0;
it = setInterval(function () {
  for (var p = 0; p < 150; p++) {
    hue(p, h + p * 13, 5);
  }
  h = (h + 7) % 768;
  update();
}, 33);