var b = require('bonescript');
var delay = 500;
b.pinMode('USR0', 'out');
b.pinMode('USR1', 'out');
b.pinMode('USR2', 'out');
b.pinMode('USR3', 'out');
var index = -1;

var tab = new Array('USR0', 'USR1', 'USR2', 'USR3');

// i is the index to turn on
function led()
{
  for (var i = 0; i < tab.length; i++) {
    console.log("Setting " + index + " to " + i);
    b.digitalWrite(tab[i], (index == i) ? b.HIGH: b.LOW);
  }
  setTimeout(function(){index = (index + 1) % tab.length; led();}, delay);
}

console.log('Start...');
// turn off all lights with an out of range index, and start the recursive calls
led();
console.log(delay+ ' more msec...');