#include <reg51.h>
#include <absacc.h>
#define uchar unsigned char
#define uint unsigned int
void delays(void);
uchar kbscan(void);
void main(void)
{
uchar key;
while(1)
{
key=kbscan();    /*鍵掃描函數(shù)*/
delays();     /*鍵消抖的延時函數(shù)*/
}
}

// 鍵消抖的延時函數(shù)
void delays(void)
{
uchar i;
for(i=300;i>0;i--);
}

//  kbscan(void) 鍵掃描函數(shù)
uchar kbscan(void) 
{
uchar sccode,recode;
P1=0xf0;        /*發(fā)全"0"行掃描碼，列線輸入*/
if((P1&0xf0)!=0xf0)      /*若有鍵按下*/
{
delays();          /*延時去抖動*/
if((P1&0xf0)!=0xf0)
{
sccode=0xfe;     /*逐行掃描初值*/
while((sccode&0x10)!=0)
{
P1=sccode;     /*輸出行掃描碼*/
if((P1&0xf0)!=0xf0)      /*本行有鍵按下*/
{
recode=(P1&0xf0)|0x0f;
return((~sccode)+(~recode)); /*返回特征字節(jié)碼*/
}
else sccode=(sccode<<1)|0x01; /*行掃描碼左移一位*/
}
}
}
return(0);        /*無鍵按下，返回值為0*/
}