摘要:近100年以来，人类的科技文明成果超过了100年以前的整个文明史总和。科学正以前未所有的速度在进步，科技月新日异，技术不断更新，交通灯便是人类进步中的一大发明。

随着汽车的普及，城市的交通压力越来越大，除了增加道路的建设，提高对道路的交通管理也成了重中之重。一个好的交通灯控制系统，将给道路拥挤、违章控制等方面给予技术革新。十字路口车辆穿梭，行人熙攘，车行车道，人行人道，有条不紊。如何能做到这样？靠的是交通信号灯的自动指挥系统。交通信号灯控制方式很多。本系统采用89系列单片机STC89C52为中心器件来设计交通灯控制器，实现了通过STC89C52芯片的P0、P2口设置红、绿灯燃亮时间的功能；显示时间通过STC89C52的P3、0 P3、1口输出到七段数码管显示，它用简单的硬件电路模拟交通灯信号灯的交替变换，实现红绿灯循环点亮。用LED数码管作为倒计时指示。

在软件方面运用单片机汇编语言设置并控制信号灯的基本变化，同时实施处理个检查装置的输入的数据，判断产生对信号灯的变化控制以实现交通灯的设计模系统实用性强、操作简单、扩展性强。

关键词 :交通灯 ；单片机STC89C52 ；LED 七段数码管

Abstract:In the last 100 years, human civilization achievements of science and technology of more than 100 years before the whole sum of civilization., Science is not all the speed before in progress . Science and technology constantly updated each month even each day. The traffic lights is one of the great inventions in human progress.

With the popularity of the car, and the city's traffic pressure is bigger and bigger, in addition to increasing the road construction, improve the management of road traffic has also become a top priority. A good traffic control system, will give road congestion, illegal control to give technical innovation. Crossroads transports, bustling pedestrian, auto lane, a humanitarian, in an orderly way. How do you do this? By the traffic lights automatic command system. There are many ways to control the traffic lights. The system USES the 89 series microcontroller STC89C52 as the center device to designing traffic light controller, realized through the STC89C52 chip P0, P2 mouth set red, green lit the function of the time; Show time STC89C52 through the P3, 0 P3, 1 output to the mouth for seven digital pipe display, it with simple hardware circuit simulation traffic lights alternates alternately, realize the traffic light cycle lighted. Use LED digital tube as countdown instructions.

In software using single chip assembly language Settings and control signal lamp basic change, at the same time implementing processing an inspection device of input data, judgment to the change of light produced in order to realize the design of the traffic control modeling system practical, simple operation and expandability.

Key words: Traffic lights Single-chip microcomputer AT89C52 LED for seven digital tube