51单片机矩阵

unsigned char key()
{
   unsigned char keyNum;
   P1=0xFF;
   P1_7=0;
   if(P1_3==0){Delay(20);while(P1_3==0);Delay(20);keyNum=1;}
   if(P1_2==0){Delay(20);while(P1_2==0);Delay(20);keyNum=2;}
   if(P1_1==0){Delay(20);while(P1_1==0);Delay(20);keyNum=3;}
   if(P1_0==0){Delay(20);while(P1_0==0);Delay(20);keyNum=4;}

   P1_6=0;
   if(P1_3==0){Delay(20);while(P1_3==0);Delay(20);keyNum=5;}
   if(P1_2==0){Delay(20);while(P1_2==0);Delay(20);keyNum=6;}
   if(P1_1==0){Delay(20);while(P1_1==0);Delay(20);keyNum=7;}
   if(P1_0==0){Delay(20);while(P1_0==0);Delay(20);keyNum=8;}

   P1_5=0;
   if(P1_3==0){Delay(20);while(P1_3==0);Delay(20);keyNum=9;}
   if(P1_2==0){Delay(20);while(P1_2==0);Delay(20);keyNum=10;}
   if(P1_1==0){Delay(20);while(P1_1==0);Delay(20);keyNum=11;}
   if(P1_0==0){Delay(20);while(P1_0==0);Delay(20);keyNum=12;}

   P1_4=0;
   if(P1_3==0){Delay(20);while(P1_3==0);Delay(20);keyNum=13;}
   if(P1_2==0){Delay(20);while(P1_2==0);Delay(20);keyNum=14;}
   if(P1_1==0){Delay(20);while(P1_1==0);Delay(20);keyNum=15;}
   if(P1_0==0){Delay(20);while(P1_0==0);Delay(20);keyNum=16;}

return keyNum;
}

51单片机 矩阵

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