#include<reg51.h>
#define uchar unsigned char
#define uint unsigned int
sbit RED_A=P0^0; //东西向灯
sbit YELLOW_A=P0^1;
sbit GREEN_A=P0^2;
sbit RED_B=P0^5; //南北向灯
sbit YELLOW_B=P0^4;
sbit GREEN_B=P0^3;
uchar Flash_Count=0,Operation_Type=1; //闪烁次数,操作类型变量
void DelayMS(uint x)
{
uchar i;
while(x--)
for(i=0;i<120;i++);
}
void Traffic_Light()
{
switch(Operation_Type)
{
case 1: //东西向绿灯与南北向红灯亮
RED_A=1;
YELLOW_A=1;
GREEN_A=0;
RED_B=0;
YELLOW_B=1;
GREEN_B=1;
DelayMS(3000);
Operation_Type=2;
break;
case 2: //东西向黄灯闪烁,绿灯关闭
DelayMS(500); //延时下面的YELLOW_A=1的状态,YELLOW_A=1是从case1里的状态延续下来的
YELLOW_A=~YELLOW_A;
GREEN_A=1;
if(++Flash_Count!=10) return; //当if里面的条件不成立,(return)就会返回到Traffic_Light,从新开始执行
Flash_Count=0; //从新执行时由于swich语句是一个一个语句块的执行,下次执行依然会从语句块2开始执行
Operation_Type=3;
break;
case 3: //东西向红灯,南北向绿灯亮
RED_A=0;
YELLOW_A=1;
GREEN_A=1;
RED_B=1;
YELLOW_B=1;
GREEN_B=0;
DelayMS(3000);
Operation_Type=4;
break;
case 4: //南北向黄灯闪烁 5 次绿灯关闭
DelayMS(500);
YELLOW_B=~YELLOW_B;
GREEN_B=1;
if(++Flash_Count!=10) return;
Flash_Count=0;
Operation_Type=1;
}
}
//主程序
void main()
{
while(1) Traffic_Light();
}
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