for(;;)
    {
    task1();
    task2();
    task3();
    // ...
    }

void BlinkLed(unsigned short Blink_Count, unsigned short LED_on_ms, unsigned short LED_off_ms)

unsigned short clock(void){
  unsigned short tms;
  __enter_critical();          
  tms = xtimer_ms;
  __exit_critical();
  return (tms);        

}

unsigned short clock_Elapsed(unsigned short tstart){
  return ((unsigned short)( clock() - tstart));
}

static unsigned short BCount;
static unsigned short Bon_ms;
static unsigned short Boff_ms;
static unsigned short Bts_ms;

void xBlinkLed_Start(unsigned short Blink_Count, unsigned short LED_on_ms, unsigned short LED_off_ms){
  BCount = Blink_Count;
  Bon_ms = LED_on_ms;
  Boff_ms = LED_off_ms;
  Bts_ms = clock();
  LED_OFF();
}

bool xBlinkLed_Done(bool forceoff){
  static unsigned char st = 0;
  if(forceoff){
    BCount = 0;
    st = 0;
    LED_OFF();
  }
  if(BCount){
    switch(st){
    case 0:
            if(clock_Elapsed(Bts_ms) < Boff_ms)break;
            LED_ON();  Bts_ms = clock();      
            st = 1;

    case 1: if(clock_Elapsed(Bts_ms) < Bon_ms)break;
            LED_OFF(); Bts_ms = clock();
            BCount -= 1;                
            st = 0;
            break;

    default:
            st = 0;
            break;
    }
  }
  if(BCount == 0){ return true;}
  return false;
}