/**
1、初始状态：南北绿，东西红（25s）;后转为过渡状态：南北黄，东西红（5s）;
再转为东西通行状态:东西绿，南北红（25s）;再转为过渡状态：东西黄，南北红，然后循环往复
2、键控：
		按下k1键，保持南北通行状态
		按下k2键，保持东西通行状态
		按下k3键，保持正常交通灯
3、具有闪烁的交通灯：
	在2的基础上增加，绿灯最后5s闪烁，即亮0.5s,灭0.5s
**/ 
#include <reg52.h>
#define uint  unsigned int
#define uchar unsigned char
sbit  key0 = P2^0;				 //按键位定义,k1/2/3可控
sbit  key1 = P2^1;
sbit  key2 = P2^2;
sbit  key3 = P2^3;

sbit  sou_g = P1^2;				 //南绿灯位定义
sbit  nor_g = P0^0;				 //北绿灯位定义
sbit  eas_g = P0^3;				 //东绿灯位定义
sbit  wes_g  = P1^5;			 //西绿灯位定义

uchar flag = 0, sec = 0;		  //T0定时标志位
//uchar flag_key = 0;			  //按键检测标志
uchar flag_flash = 0;
uchar flag2 = 0;				  //用以判断是东西还是南北的绿灯闪烁

void main()
{
	TMOD = 0X11;				   //定时器0、1都设置为方式1
	TH0 = (65535 - 50000) / 256;   //定时器0赋初值
	TL0 = (65535 - 50000) % 256;
	TH1 = (65535 - 50000) / 256;   //定时器1赋初值
	TL1 = (65535 - 50000) % 256;
	ET0 = 1;					   //允许定时器0中断
	ET1 = 1;					   //允许定时器1中断
	EA = 1;						   //开总中断
	
	EX0 = 1;				 //允许外部中断0中断
	IT0 = 1;				 //设置外部中断0为跳沿触发方式

	P0 = 0xfc;				 //南北绿
	P1 = 0xf3;			     //东西红
	TR0 = 1;				 //开定时器0
	while(1);
}


void int0(void) interrupt 0		//外部中断0
{
	if(!key0)				//key0键无功能设定
	{		}
	if(!key1)				//按下key1，保持南北通行状态
	{
		TR0 = 0;			//关闭定时器0，即关闭正常状态
		P0 = 0xfc;			//保持南北通行状态
		P1 = 0xf3;
	}
	if(!key2)				//按下key2，保持东西通行状态
	{
		TR0 = 0;
		P0 = 0xf7;			//保持东西通行状态
		P1 = 0x9e;
	}
	if(!key3)				//按下key3，保持正常交通灯
	{
		flag = 0;			//重新恢复正常状态，所以进行标志初始化，相当于重新开始
		sec = 0;//既然是恢复正常状态，那就相当于重新开始，出于这个考虑，所有标志位恢复初始值
		TH0 = (65535 - 50000) / 256;		//初始化T0值
		TL0 = (65535 - 50000) % 256;
		P0 = 0xfc;							//恢复初始状态，南北绿，东西红
		P1 = 0xf3;
		TR0 = 1;							//重新打开定时器0中断
	}
}
void t0(void) interrupt 1
{
	TH0 = (65535 - 50000) / 256;			//方式1必须重装初值
	TL0 = (65535 - 50000) % 256;
	flag++;									//定时标志位自加
	if(flag == 20)
	{
		flag = 0;
		sec++;				 //每计满1s,sec加1
		/*在用switch的时候一定不要忘了break;还有就是一定要搞清楚这个语法点*/
		switch(sec)
		{
			case 3:				 //在绿灯最后1S，打开定时器1，关设置标志flag2
				flag2 = 1;
				TR1 = 1;
					break;//只要进行过任意一个处理，完毕后即跳出，不再执行后续程序
			case 4:				 //关闭定时器1，绿灯不再闪烁
				TR1 = 0;
				P0 = 0xfd;		 //过渡状态
				P1 = 0x75;
					break;	
			case 6:
				P0 = 0xf7;		 //东西通行状态
				P1 = 0x9e;
					break;
			case 9:				   //在绿灯最后1S，打开定时器1，关设置标志flag2
				flag2 = 2;
				//TH1 = (65535 - 50000) / 256; //这两句应该是要的，严谨的话
				//TL1 = (65535 - 50000) % 256;
				flag_flash = 0;		//T2计时标志清0，为了更准确
				TR1 = 1;			//打开定时器1
					break;			//万不可漏了 “break;”
			case 10:
				TR1 = 0;			//关闭定时器1
				P0 = 0xfb;			//东西黄、南北红，过渡状态
				P1 = 0xae;
					break;
			case 12:
				sec = 0;			//sec清0,回到初始状态
				P0 = 0xfc;
				P1 = 0xf3;
					break;
		}
		/*下面为第二种方式
		if(sec == 4)
		{
			P0 = 0xfd;
			P1 = 0x75;
		}
		if(sec == 6)
		{
			P0 = 0xf7;
			P1 = 0x9e;
		}
		if(sec == 10)
		{
			P0 = 0xfb;
			P1 = 0xae;
		}
		if(sec == 12)
		{
			sec = 0;
			P0 = 0xfc;
			P1 = 0xf3;
		}*/
	}
}
void t2(void) interrupt 3
{
	TH1 = (65535 - 50000) / 256;
	TL1 = (65535 - 50000) % 256;
	
	if(flag2 == 1)				//如果为南北通行状态，则南北绿灯闪烁
	{	
		flag_flash++;			//定时标志自加
		if(flag_flash == 4)
		{
			flag_flash = 0;		//标志清0
			sou_g = ~sou_g;		//南绿灯取反，下同
			nor_g = ~nor_g;
		}
	}
	if(flag2 == 2)				 //如果为东西通行状态，则东西绿灯闪烁
	{
		flag_flash++;
		if(flag_flash == 4)
		{
			flag_flash = 0;
			eas_g = ~eas_g;
			wes_g = ~wes_g;
		}
	}
	
}