我想一片8255做一个矩阵键盘,PA口八个口作列线,PC0到PC4作行线加上拉电阻接电源,下面程序,但编译不过去,希望高手们指点下:
#include <REG51.H>
#include<absacc.h>
#define uchar unsigned char
#define uint unsigned int
void delay (uint);
uchar scankey(void);
uchar keyscan(void);
void main(void)
{
uchar key;
while (1)
{
key = keyscan();
delay (2000);
}
}
// 延时//
void delay(uint i)
{
uint j;
for (j=0;j<i;j++)
{}
}
//检测有无按键//
uchar checkkey() //检测按键,有返回0XFF,无返回0//
{
uchar i;
XBYTE[0x7f00]=0x00;
i=XBYTE[0x7f02];
i=i&0x0f;
if (i= = 0x0f) return (0);
else return (0xff);
}
// 键盘扫描//
uchar keyscan()//扫描键盘,有键按下返回键编码,无返回0XFF//
{
uchar scancode;//列扫描变量//
uchar codevalue;//返回的编码变量//
uchar m;//行首编码变量//
uchar k;//行检测码//
uchar i,j;
if (checkkey()= =0) return (0xff);//检测按键,无返回0XFF//
else
{
delay(200);
if (checkkey()= =0) return (0xff);
else
{
scancode=0xfe;m=0x00;//列扫描码,行首码赋初值
for(i=0;i<8;i++)
{ k=0x01;
XBYTE[0x7f00]=scancode;//送列扫描码
for (j=0;j<4;j++)
{
if ((XBYTE[0x702]&k = = 0)//检测当前行是否有键按下
{
codevalue=m+j;//有,求编码
while(checkkey()!=0);//等键释放
return (codevalue);//返回编码
}
else k=k<<1;//检测下一行
}
m=m+8;//计算下一行首编码
scancode=scancode<<1;//列扫描码左移一位,扫描下一列
}
}
}
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