说明：  包含proteus仿真文件及c语言程序，在开发板上进行过运行。利用双色LED显示电路，和四位静态数码管显示电路模拟十字路口交通信号灯。4位LED数码管显示时间，双色LED灯显示红绿灯状态。熟悉交通信号灯控制逻辑。设计一个十字路口的交通灯控制电路，要求南北方向和东西方向两个交叉路口的车辆交替运行。每次绿灯变红灯时,要求黄灯先亮3S,才能变换运行车辆。东西方向、南北方向车道除了有红、黄、绿灯指示外，每一种灯亮的时间都用数码管显示器进行显示（采用倒计时的方法）。考虑到特殊车辆情况，设置紧急转换开头。
(It contains proteus simulation file and C language program. It has been run on the development board. Two-color LED display circuit and four-bit static digital tube display circuit are used to simulate traffic lights at intersections. Four-bit LED digital tube display time, two-color LED lights show the status of traffic lights. Familiar with traffic signal control logic. Design a traffic light control circuit at the intersection, which requires the vehicles running alternately in the north-south direction and the East-West direction. Every time the green light turns red, the yellow light is required to turn on 3S before changing the running vehicle. In addition to the red, yellow and green lights in the east-west and North-South lanes, the time of each kind of light is displayed by digital tube display (countdown method). Considering the special vehicle situation, set up the emergency switch start.)