单片机按键控制程序

行线选择的是P2-0至P2-3

列线选择的是P2-4至P2-7

该程序按键消抖效果较好

#include

#define unit unsigned int

#define uchar unsigned char

uchar code table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x83,0xf8,0x80,0x98}; void delay(unit z);

uchar key_scan();

uchar num,temp;

void main()

{

while(1)

{ key_scan();

P0=table[num];

}

}

/*******************

延时子程序********************************/

void delay(unit z)

{unit x,y;

for(x=z;x>0;x--)

for(y=100;y>0;y--);

}

/*键盘扫描子程序*/

uchar key_scan(void)

{ P2=0xfe;

temp=P2;

temp=temp&0xf0;

if(temp!=0xf0)

{ delay(1);

temp=P2;

temp=temp&0xf0;

if(temp!=0xf0)

{ temp=P2;

switch(P2)

{

case 0xee:num=1;

break;

case 0xfe:num=2;

break;

case 0xbe:num=3;

break;

case 0x7e:num=4;

break;

}

}

}

}