利用外部中断接受红外信号，定时器计时，红外信号高低电平时间不同，因而可以根据时间把信号分离出来，然后再六位数码管上显示出红外的信号-IR signals received by external interrupt, the timer, infrared signal high and low at different times, so the signal can be separated by time, and then six digital signals to display the infrared