void Getchar ( )
{
unsigned char X,Y,Z;
P1=0x0f;
if(P1!=0x0f)
{
delay10ms();
if(P1!=0x0f)
{
X=P1;
P1=0xf0;
Y=P1;
Z=X|Y;
switch ( Z )
{
case 0xee: k=0; break;
case 0xed: k=1; break;
case 0xeb: k=2; break;
case 0xe7: k=3; break;
case 0xde: k=4; break;
case 0xdd: k=5; break;
case 0xdb: k=6; break;
case 0xd7: k=7; break;
case 0xbe: k=8; break;
case 0xbd: k=9; break;
case 0xbb: k=10;break;
case 0xb7: k=11;break;
case 0x7e: k=12;break;
case 0x7d: k=13;break;
case 0x7b: k=14;break;
case 0x77: k=15;break;
}
}
}
}