4x4 4x4键盘问题,有四个键值始终不对,请大家帮帮忙
[#TK1117] 4x4 4x4键盘问题,有四个键值始终不对,请大家帮帮忙
用89c2051做了一个键盘,P1.0-P1.3接上拉电阻,程序如下:
uchar getkey()
{
uchar recode,key;
uchar sccode;
P1=0xF0;
if((P1&0xF0)!=0xF0)
{
delay(200); //延时1MS
if((P1&0xF0)!=0xF0)
{
sccode=0xFE;
while((sccode&0x10)!=0)
{ P1=sccode;
if((P1&0xF0)!=0xF0)
{
recode=(P1&0xF0)|0x0F;
keydd=0; key=(~sccode)+(~recode);
key=changekey(key);
return (key); }
else sccode=(sccode<<1)|0x01;
}
}
}
if((P1&0xF0)==0xF0)
{
delay(200);
if((P1&0xF0)==0xF0)
{
keydd=1;
return 0;
}
}
}
uchar changekey(uchar keystate)
{
switch(keystate)
{
case 0x41: keystate=0x47;break;
case 0x42: keystate=0x49;break;
case 0x44: keystate=0x45;break;
case 0x48: keystate=0x42;break;
case 0x22: keystate=0x48;break;
case 0x24: keystate=0x46;break;
case 0x28: keystate=0x43;break;
case 0x11: keystate=0x51;break;
case 0x12: keystate=0x16;break;
case 0x14: keystate=0x11;break;
case 0x18: keystate=0x41;break;
*case 0x01: keystate=0x50;break;
*case 0x02: keystate=0x15;break;
*case 0x04: keystate=0x12;break;
*case 0x08: keystate=0x44;break;
default: break;
}
DOG=!DOG;
return (keystate);
}
其中打*的四句不对,始终得不到我想要的值(如:keystate=0x50等),其他的都没有问题。一直没有找到原因!请大家帮帮忙看一下,谢谢!