key4x4.c

4x4键盘试验源代码

#include <reg51.h>

#define DELAYTIME  40

sbit a=P1^0;
sbit b=P1^1;
sbit c=P1^2;
sbit d=P1^3;

char test[4]={0x7f,0xbf,0xdf,0xef};

void P2_Disp(unsigned char x)
{
 P2=~x;
}

void delay(unsigned long time)
{
 while(time--);
}

void main()
{
 int i=0;

 P1=0xff;
 delay(400);

 while(1)
 {
  P1=0xff;
  for(i=0;i<4;i++)
  {
   P1=0xff;
   P1=P1&test[i];
   delay(DELAYTIME);
   if(a!=1) 
     {
      delay(DELAYTIME);
      if(a!=1)
      {
       P2_Disp((3-i)*4+1);
      }
     }
   if(b!=1) 
     {
      delay(DELAYTIME);
      if(b!=1)
      {
       P2_Disp((3-i)*4+2);
      }
     }
   if(c!=1) 
     {
      delay(DELAYTIME);
      if(c!=1)
      {
       P2_Disp((3-i)*4+3);
      }
     }
   if(d!=1) 
     {
      delay(DELAYTIME);
      if(d!=1)
      {
       P2_Disp((3-i)*4+4);
      }
     }
 }
}

while(1);
}