var b = require('bonescript');
var state = b.HIGH;
var delay = 500;
b.pinMode('USR0', 'out');
b.pinMode('USR1', 'out');
b.pinMode('USR2', 'out');
b.pinMode('USR3', 'out');

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

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

console.log('Start...');
// turn off all lights with an out of range index, and start the recursive calls
led (-1);
console.log(delay+ ' more msec...');