这个小程序是调用定时器中断方式模拟交通灯，先红灯亮10秒，接着黄灯亮三秒，然后绿灯再亮10秒，依次循环-This applet is called timer interrupt simulation of traffic lights, the first red light for 10 seconds, then yellow light for three seconds, then green and then light for 10 seconds, followed by cycle