单片机C语言之按键，数码管加减

#ifndef _KEY_H_
#define _KEY_H_
typedef unsigned char uint8;
typedef unsigned int uint16;
typedef char int8;
typedef int int16;
sbit KeyIn4 = P2^7;
sbit keyIn3 = P2^6;
sbit KeyIn2 = P2^5;
sbit keyIn1 = P2^4;
sbit KeyOut1 = P2^3;
sbit keyOut2 = P2^2;
sbit KeyOut3 = P2^1;
sbit keyOut4 = P2^0;
sbit ADDR0 = P1^0;
sbit ADDR1 = P1^1;
sbit ADDR2 = P1^2;
sbit ADDR3 = P1^3;
sbit ENLED = P1^4;

#endif

key.h ↑

key.c↓

按一下KeyInt1 数码管加1，按一下KeyInt2 数码管减1。

#include<reg51.h>
#include "key.h"

code uint8 number[] = {0xc0,0xf9,0xa4,0xb0,0x99,
                       0x92,0x82,0xf8,0x80,0x90,
                       0xFF};
int8 n = 0;
main()
{ 
    P0 = 0xff;
    KeyOut1 = 0;
    ENLED = 0;ADDR3=1;
    ADDR0 = 0; ADDR1 = 0; ADDR2 = 0;
    P0 = number[0];
    while(1)
    {
        if(!KeyIn1){
            if(n>=9) n=0;
            else n++;
            P0 = number[n];
            while(!KeyIn1);
        }
        if(!KeyIn2){
            if(n<=0) n=9;
            else n--;
            P0 = number[n];
            while(!KeyIn2);
        }
    }
}

硬件去抖，加电容去高频。

软件去抖，检测出键闭合后执行延时程序，前沿抖动消失后再次检测键的状态。

#include<reg51.h>
#include "key.h"

code uint8 number[] = {0xc0,0xf9,0xa4,0xb0,0x99,
                       0x92,0x82,0xf8,0x80,0x90,
                       0xFF};
void delay()
{
    uint16 i = 1000;
    while(i--);//roughly delay
}
int8 n = 0;
main()
{ 
    P0 = 0xff;
    KeyOut1 = 0;
    ENLED = 0;ADDR3=1;
    ADDR0 = 0; ADDR1 = 0; ADDR2 = 0;
    P0 = number[0];
    while(1)
    {
        if(!KeyIn1){
            delay();
            if(!KeyIn1){
                if(n>=9) n=0;
                else n++;
                P0 = number[n];
                while(!KeyIn1);
            }
        }
        if(!KeyIn2){
            delay();
            if(!KeyIn2){
                if(n<=0) n=9;
                else n--;
                P0 = number[n];
                while(!KeyIn2);
            }
        }
    }
}