51矩阵键盘程序及电路连接图

//按键码表

uchar code KeyCodeTable[]=

{

0x11,0x12,0x14,0x18,0x21,0x22,0x24,0x28,0x41,0x42,0x44,0x48,0x81,0x82,0x84,0x88

};

//延迟小程序，一般20ms

void Delay(void)

{

uchar i;

for(i=0;i200;i++);

}

//按键检测程序

uchar Keys_Scan(void)

{

uchar sCode,kCode,i,k;

P1 = 0xf0;

//是否有键被按下

if((P1&0xf0)!=0xf0)

{

Delay();

if((P1&0xf0)!=0xf0)

{

sCode = 0xfe;

for(k=0;k4;k++)

{

P1 = sCode;

if((P1&0xf0)!=0xf0)

{

kCode = ~P1;

for(i=0;i16;i++)

{

if(kCode == KeyCodeTable)

return i;

}

}

else

{

sCode = _crol_(sCode,1);

}

}

}

}

return -1;

}