单片机4*4按键数码管显示0-9

 

单片机4*4按键数码管显示0-9

 

#include<reg51.h>
#define KEY    P1  //键盘
#define SEG    P0  //数码管
sbit COM=P2^0; // 数码管com
sbit OC = P2^1;//573锁存器 

char code TAB[]={//0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xa7,0xa1,0x84,0x84,0xbf,0x7f};//共阳极
                0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7D,0x07,0x7f,0x6F};  //共阴极

unsigned char scan[4]={0xef,0xdf,0xbf,0x7f}; //扫描码 低电平动作扫描

void delay1ms(int x);

void main(void)
{    
    unsigned char col,row;           //定义列行
    unsigned char rowkey,kcode;      //定义按键，按键码
     COM=0; //点亮数码管
     OC=0; // 低电平使能
    while(1)
    {
        for(col=0;col<4;col++)      //4列按键
       {
        KEY =scan[col];
        rowkey = ~KEY&0X0F;          //例如 读入低4位 反相清除高4位，求出行键值
        while(rowkey!=0)          //如果按下键
        {
              if(rowkey==0x01)   row = 0;     //如果第0行被按下
            if(rowkey ==0x02)  row = 1;     //如果第1行被按下
            if(rowkey == 0x04) row = 2;     //如果第2行被按下
            if(rowkey == 0x08) row = 3;     //如果第3行被按下
            kcode = 4*col+row;      //算出按键号码
            SEG = TAB[kcode];      //显示
            while(rowkey!=0)      //如果未放开
            rowkey = ~ KEY&0x0f;  //再次读入
     
         }
      
             delay1ms(1);    //消除抖动1ms
       }
   }
} 

 
    void delay1ms(int x) //延迟消抖
{
     int i,j;
     for(i=0;i<x;i++)
     for(j=0;j<120;j++);  // 120 * 8 = 960us = 1ms 
}