struct etimer

{

  struct timer timer;

  struct etimer *next;

  struct process *p;

};

struct etimer timeout;

PROCESS(test_process, "Test Process");

AUTOSTART_PROCESSES(&test_process);

PROCESS_THREAD(test_process, ev, data)

{

  PROCESS_BEGIN(); 

  etimer_set(&timeout,CLOCK_SECOND); //设置etimer溢出时间为1s

  while(){

    PROCESS_WAIT_EVENT();//等待事件发生，线程会暂时停止在这行

    if(ev == PROCESS_EVENT_TIMER){ //etimer溢出

      leds_on(LEDS_YELLOW); //开灯

      etimer_reset(&timeout); //重设定时器时间，也就是第一次设定时的1s

    }

    PROCESS_WAIT_EVENT();//等待事件发生，线程会暂时停止在这行

    if(ev == PROCESS_EVENT_TIMER){ //etimer溢出

      leds_off(LEDS_YELLOW); //关灯

      etimer_reset(&timeout);

    }

  }

  PROCESS_END();

}