要求：4*4按键对应八位数码管显示

数码管电路图：

Pasted Graphic.jpg

4*4矩阵式键盘电路原理图：

Pasted Graphic.jpg

代码如下：

#include "reg52.h"
sbit oe = P1^3;
sbit le1 = P1^4;//传值
sbit le2 = P1^5;//片选
char code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};//共阴极的code
char code select[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
//延时函数
void delay(unsigned int ms){
          unsigned int x,y;
          for(x=0;x<ms;x++)
        for(y=0;y<110;y++);
      }
 //数码管显示函数（传入uint的数字，在八位数码管显示相应的数字）
    void display(unsigned int num){ 
    oe = 0;
    le1 = 0;
        le2 = 0;
    le1 = 1;
    P0 = table[num];
    le1 = 0;
    le2 = 1;
    P0 = select[0];
    le2 = 0;
    delay(5);
    }
      //按键检测函数（按下相应按键显示不同数字）
    void button_check(){
      unsigned int l,h,hex;
      P2 = 0xF0;//列输入，行输出
        delay(2);
        h = P2;
        delay(2);
        P2 = 0x0F;/行输入，列输出
        l = P2;
        delay(2);
        hex = l|h;//两个值相或的交点
        delay(2);
    switch(hex){
          case 0xEE://第一个E标识列，第二个E表示行
                display(0);
                break;
        
            case 0xDE:
                display(1);
                break;
            
            case 0xBE:
                display(2);
                break;
        
            case 0x7E:
                display(3);
                break;
            
            case 0xED:
                display(4);
                break;

            case 0xDD:
                display(5);
                break;
            case 0xBD:
                display(6);
                break;
            
            case 0x7D:
                display(7);
                break;
            
            
            case 0xEB:
                display(8);
                break;

            case 0xDB:
                display(9);
                break;
            
            case 0xBB:
                display(10);
                break;
            
            case 0x7B:
                display(11);
                break;
            
            case 0xE7:
                display(12);
                break;

            case 0xD7:
                display(13);
                break;
            
            case 0xB7:
                display(14);
                break;
            
            case 0x77:
                display(15);
                break;  
      }
     }
            void main(){
    while(1){
        button_check();
        delay(5);

    }
    }