#define LED 2
#define servo 15
int state = 0;
hw_timer_t * timer = Null;

void setup()
{
  pinMode(LED, OUTPUT);
  timer = timerBegin(0, 80, true);
  timerAttachInterrupt(timer & LEDControl, true);
  timerAlarmWrite(timer, 500000, true);
  timweAlarmEnable(timer);
}

void LEDControl()
{
  if(state=0)
  {
    state=1;
    digitalWrite(LED, state);
  }
    else
    {
      state = 0;
    }
    digitalWrite(LED, state);
}