0119

单片机 单个数码管实现抢答器

#include<reg52.h>

unsigned char code dofly_table[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,};
/*
void delay()
{
unsigned int i = 0;
for(i = 0; i < 32500; i++);
}  */


void main (void)
{                
unsigned char i; 
i = 0; 
P1 = 0xff;
P2 = 0xff;


/* while (1)        
{
for(i=0;i<10;i++)  
{
P1=dofly_table[i]; 
delay();  
delay();   
}         
} */
while (1)    
{
switch(P2)                           //抢答器
{
    case 0xfe: if(i == 0)
{
P1=dofly_table[1];
i = 1;
}
break;
case 0xfd:if(i == 0)
{
P1=dofly_table[2];
i = 1;
}
break;
case 0xfb:if(i == 0)
{
P1=dofly_table[3];
i = 1;
}
break;
case 0xf7:if(i == 0)
{
P1=dofly_table[4];
i = 1;
} 
break;
case 0xef:if(i == 0)
{
P1=dofly_table[5];
i = 1;
}  
break;
case 0xdf:if(i == 0)
{
P1=dofly_table[6];
i = 1;
}  
break;
case 0xbf:if(i == 0)
{
P1=dofly_table[7];
i = 1;
}
break;
case 0x7f:i = 0; P1 = 0xff;break;
default:break;   
  }
}
}