键盘程序2.txt

这是几个常用的键盘扫描程序

#include <reg51.h>
#include <intrins.h>
#define unint unsigned int
#define unchar unsigned char
#define dsout P3//数码管字形
#define dsrun P1//数码管选通
#define keybord P2//键盘
sbit row1=P2^4;//键盘行
sbit row2=P2^5;
sbit row3=P2^6;
sbit row4=P2^7;
/*************P3.4~3.0分别为列1,2,3,4**********************/
unchar code dscode[]={0x3f,0x6,0x5b,0x4f,0x66,0x6d,0x7d,0x7,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
/*******************消抖*********************/
void del(void)
{
    unint i;
    for (i=1;i<=10000 ;i++ );
}
/******************判断是否按键****************/
bit keyscan(void)
{
    keybord=240;//高4位为1,低4位为0
    if (keybord!=240)
       return 0;//有键按下为1
    else
        return 1;//无键按下为0
}
/*****************获取键值*************************/
unchar getkey(void)
{
    unchar keynum,perp;
    keybord=247;//P3.3为0
    for (perp=0;perp<=3;perp++ )
    {            
        if (row1==0)
        {keynum=perp+0;break;}//1行值为0
        if (row2==0)
        {keynum=perp+4;break;}//2 行值为4
        if (row3==0)
        {keynum=perp+8;break;}//3为8
        if (row4==0)
        {keynum=perp+12;break;}
        else
            keybord=_cror_(keybord,1);//转下列扫描
    }
    return keynum;
}
main()
{
    unchar getcode;
    dsout=0;
    dsrun=0;//选通
    while (1)
    {    
        while (keyscan());
        del();
        getcode=getkey();
        while (~keyscan());
        del();
        dsout=dscode[getcode];

    }
}