code: function start() {
      exec(function (a) {
          var tempListeners = listeners.slice(0);
          accel = new Acceleration(a.x, a.y, a.z, a.timestamp);
          for (var i = 0, l = tempListeners.length; i < l; i++) {
              tempListeners[i].win(accel);
          }
      }, function (e) {
          var tempListeners = listeners.slice(0);
          for (var i = 0, l = tempListeners.length; i < l; i++) {
              tempListeners[i].fail(e);
          }
      }, "Accelerometer", "start", []);
      running = true;
  }
docs: Tells native to start.