利用AT89S52单片机设计并制作一个能够显示倒计时间并可人为调整时间的交通灯系统。

（二）、要求：

1． 基本要求：

(1)实时显示当前通行剩余时间；

(2) 十字路口需有剩余时间显示。东西通道、南北通道通行时间，红灯时间、绿灯时间及黄灯亮的时间均以秒为单位作减计数；（时间自定）

(3) 倒计时剩5秒时黄灯闪烁警示

(4) 能手动设置通行方向。

-Use AT89S52 microcontroller design and production of a countdown to show time and artificially adjusting the traffic light system. (Two), requires: 1. Basic requirements: (a) real-time display the current access time remaining　(2) the need for remaining time display crossroads. What channel, south channel access time, red time, the green and the yellow light time to time expressed in seconds for the minus count　(Time Custom) (3) countdown five seconds flashing yellow warning　(4) can manually set the prevailing direction.