#include <reg51.h>
#define uint unsigned int
#define uchar unsigned char
void delay(uint k);//延時
void add(void);  //把數組轉化為地址碼和數據碼 
void addled(void);  //計算出led要顯示的數
void display(void);//led顯示
void count(void);
uchar  SEG7[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};//共陽
uchar  scan_led[8]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f}; //片選 高平亮
uchar led[8]={1,2,3,4,5,6,7,8};    //每位led要顯示的數
sbit P32=P3^2;
bit finish;//結束標志位
uchar tt[33];
uchar j,t;
uchar data1,data2,address1,address2;
void main(void)
{ 
  TH0=0;TL0=0;
  TMOD=0x19;
  TR0=0;
  EX0=1;//允許中斷
  IT0=1;//下降沿中斷
  TH1=252;TL1=0;
  ET1=1;
  TR1=1;
  PT1=1;
  EA=1;
  while(1){
   if(finish==1){finish=0;
                 add();
                 //addled();
                  count();
				 }
   }
}
////////////////////////////////////////////
void delay(uint k)//延時
{k=k*8;
 while(--k);
 }
//////////////////////////////////
void int0()interrupt 0
{uchar i;
 EX0=0;
 TR0=1;
 while(P32==0);
 while(P32==1){if(TH0>20)break;}//時間大于5.3ms時就退出
 TR0=0;
 t=(TH0*256+TL0)/100;
 TH0=0;TL0=0;
 tt[0]=t;
 //if(t>42&&t<48){
 for(i=1;i<=32;i++)
                   { 
				   TR0=1;
				     while(P32==0);
                     while(P32==1){if(TH0>20)break;}//時間大于2.7ms時就退出
                     TR0=0;
				     t=(TH0*256+TL0)/100;
                     TH0=0;TL0=0;
                     //if(t>4&&t<7)
					 tt[i]=t;   //0.56ms為0
				     //if(t>15&&t<18)
					 //tt[i]=1;//1.68ms為1
					 TH0=0;TL0=0;
				   }
                 finish=1;
			//	}
 EX0=1;
}
///////////////////////////////////////////
void add(void)   //把數組轉化為地址碼和數據碼 
{uchar i;
 address1=0;
 address2=0;
 data1=0;
 data2=0;//清0
 for(i=8;i>0;i--)
 	{address1=(address1<<1)|tt[i];
 	 address2=(address2<<1)|tt[i+8];
 	 data1=(data1<<1)|tt[i+16];
 	 data2=(data2<<1)|tt[i+24];
	}
 }
///////////////////////////////////////////
void addled(void)   //計算出led要顯示的數
{if((data1+data2)==0xff)//數據碼和反碼的檢驗
   {led[7]=address1>>4;//取高位
	led[6]=address1&0x0f;//取低位
	led[5]=address2>>4;
    led[4]=address2&0x0f;
    led[3]=data1>>4;
    led[2]=data1&0x0f;
    led[1]=data2>>4;
    led[0]=data2&0x0f;
	}
}
//////////////////////////////////////////	
void display(void)//led顯示
{  P0=0xff;
   P2=scan_led[j]; //片選掃瞄
   P0=SEG7[led[j]]; //共陽段顯
   j++;
   if(j>=8)j=0;	 
 }
////////////////////////
void timer1()interrupt 3
{TH1=245;TL1=0;
 display();
 }
////////////////////////////
void count(void)
{led[7]=tt[0]/10;
 led[6]=tt[0]%10;
 led[5]=tt[1]/10;
 led[4]=tt[1]%10;
 led[3]=tt[2]/10;
 led[2]=tt[2]%10;
 led[1]=tt[3]/10; 
 led[0]=tt[3]%10;
 }