puck.js iBeacon button

puck.js

function doAdvertising() {
  console.log("starting advertise");
  require("ble_ibeacon").advertise({
    uuid : ['a', 2, 3, 4, 'b', 6, 'c', 3, 0, 'd', 8, 'e', 7, 'f', 3, 'g'], // ibeacon uuid
    major : 0x0001, // optional
    minor : 0x0001, // optional
    rssi : -59 // optional RSSI at 1 meter distance in dBm
  });
  console.log("started");
}

// Upon button press, we do something. All other times, we sleep, This is an interrupt.
// Note in sleep, NRF is awake and advertising, but JS is not executing, until the button interrupts sleep.
// In sleep and not advertising, 12uA power is used.
// In sleep and advertising at 375ms (0dBm), 25uA power is used.
setWatch(function() {
  digitalPulse(LED1,1,100);
  digitalPulse(LED3,1,100);  // Blink Purple when the button is pressed
  setTimeout(function () {   // Then, show our battery status as a red through to green for low to high.
    batteryLED();
  }, 500);
  setTimeout(function () {
    toggleAdvertising();     // Finally, toggle eddystone advertising On/Off - blue blink for adv on, red for adv off
  }, 500);
}, BTN, {edge:"rising", debounce:50, repeat:true});

function blinkRed(time) {
  digitalPulse(LED1,1,time);
}
function blinkGreen(time) {
  digitalPulse(LED2,1,time);
}
function blinkBlue(time) {
  digitalPulse(LED3,1,time);
}
function blinkYellow(time) { // It seems to multiplex these - even though espruino is single-threaded
  digitalPulse(LED1,1,time);
  digitalPulse(LED2,1,time);
}

// This function blinks the LEDs depending on battery status.
// Puck.getBatteryPercentage is the nicer way to check your battery status
// For the curious: NRF.getBattery() will give you raw voltage read from the NRF IC.
function batteryLED(){
  blvl=Puck.getBatteryPercentage();
  if (blvl >= 75) {                // If battery is above 75%, blink green
    blinkGreen(100);
  }
  if (blvl < 75 && blvl > 25 ) {   // If battery is lower than 75%, blink yellow
    blinkYellow(100);
  }
  if (blvl < 25) {                 // If battery is lower than 25%, blink red!
    blinkRed(100);
  }
}

var sleep = function (miliseconds) {
   var currentTime = new Date().getTime();
   while (currentTime + miliseconds >= new Date().getTime()) {
   }
};

//This function toggles whether advertising is on or off.
function toggleAdvertising() {
  // Enable Advertising, blink blue LED to reflect this.
  setTimeout(function () {
    blinkBlue(500);
    doAdvertising(); //Call doAdvertising function at top
    sleep(500);
    blinkRed(500);
    console.log("stopping");
    NRF.setAdvertising({}); //Cancel all advertising.
    console.log("stopped");

  }, 400);
}