CodeSchoolEspruino1.js

SPI1.setup({ baud:3200000, mosi: A7 });
 
var brightness = 0;
var delta = 1;
var maxBrightness = 250;

var numLeds = 12;
var data = new Uint8ClampedArray(numLeds * 3);

function sendFrame(data) {
  SPI1.send4bit(data, 0b0001, 0b0011);
}

data.fill(0);
sendFrame(data);

pinMode(B4, "input_pulldown");

setWatch(function() {
  for(var i = 0; i < data.length; i++) {
    data[i] = (0.5 * Math.random() / 2) * maxBrightness;
  }
  
  sendFrame(data);
}, B4, { repeat: true, debounce : 50, edge: "rising" });