使用单片机进行交通信号灯的模拟控制。以红、绿、黄色两组6个发光二极管表示交通信号灯。执行程序，初始态为四个路口的红灯全亮之后，东西路口的绿灯亮，南北路口的红灯亮，东西路口方向通车，延时一段时间后东西路口的绿灯熄灭，黄灯开始闪烁，闪烁若干次后，东西路口红灯亮，而同时南北路口的绿灯亮，南北路口方向开始通车，延时一段时间后，南北路口的绿灯熄灭，黄灯开始闪烁，闪烁若干次后，再切换到东西路口方向，之后重复以上过程。两个路口都有LED数码管组成的倒计时秒钟显示器当有急救车到达时，东西南北两个方向的交通信号红灯全亮，以便让急救车通过。急救车通过后，交通灯恢复中断前的状态。-Microcontroller analog control traffic lights. Red, green, yellow indicates traffic lights in two groups of six light-emitting diodes. After the implementation of the program, the initial state for the four intersection red light all light thing intersection green light is lit, the red light of the North-South junction, the opening of the things junctions direction, time delay things junction green light goes yellow light started flashing blink several times, something intersection red light, while the green light of the north-south junction, north-south junction direction was opened, after the delay time, the north-south intersection green light is off, the yellow light started flashing, blinking several times, then switch to something junctions direction, after repeating the above process. Two junctions have LED digital tube display countdown seconds when the ambulance arrived, full bright red light traffic signal in the North and South, East and West in both directions to allow emer