51 MCU C Programming (V. Matrix Keyboard Scanning and Display)

//Program name: Matrix keyboard scanning and display

//    Programming : jumpmysoul

#include
tab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xa7,0xa1,0x86,0x8e};
void disp(char);  // Digital tube display subroutine
void delay(int);  // Delay subroutine
void keyscan();   // Keyboard scanning subroutine
char keynum;

//*********************Main function********************************

void main()
{ 
 while(1)
 {
   keyscan();
   disp(keynum);
 }
}

//*********************Keyboard scanning subfunction****************************
void keyscan()      // Line reversal method
{
  char lie,hang,temp1,temp2;
   P1=0x0f;
      delay(10);
  if(P1!=0x0f)
  {
   
    if(P1!=0x0f)
    {
    temp1=temp2=P1;
    hang=temp1&0xf0;
    P1=temp2&0xf0;
    if(P1!=(temp2&0xf0))
   {
    lie=P1&0x0f;
    }
    keynum=lie|hang;
    disp(keynum);
     }
   }
}

//*********************Digital tube display sub-function****************************

void disp(char x)
{
  switch(x)
  {
   case 0x11:P0=tab[0];break;
   case 0x12:P0=tab[1];break;
   case 0x14:P0=tab[2];break;
   case 0x18 :P0=tab[3];break;
   case 0x21:P0=tab[4];break;
   case 0x22:P0=tab[5];break;
   case 0x24:P0=tab[6];break;
   case 0x28:P0 =tab[7];break;
   case 0x41:P0=tab[8];break;
   case 0x42:P0=tab[9];break;
   case 0x44:P0=tab[10];break;
   case 0x48:P0=tab [11];break;
   case 0x81:P0=tab[12];break;
   case 0x82:P0=tab[13];break;
   case 0x84:P0=tab[14];break;
   case 0x88:P0=tab[15];break;
  default: P0=0xc0;break;
 
  }
}

//*********************Delay sub-function****************************

void delay(int s)
{
 int i,j;
 for(i=s;i>0;i--)
   for(j=100;j>0;j--);
}