简单的单片机矩阵键盘程序 -

标题: 简单的单片机矩阵键盘程序 [打印本页]

作者: 983684119 时间: 2016-1-8 21:04
标题: 简单的单片机矩阵键盘程序
#include <reg52.h>

sbit ADDR0 = P1^0;
sbit ADDR1 = P1^1;
sbit ADDR2 = P1^2;
sbit ADDR3 = P1^3;
sbit ENLED = P1^4;
sbit KEY1 = P2^4;
sbit KEY2 = P2^5;
sbit KEY3 = P2^6;
sbit KEY4 = P2^7;

unsigned char code LedChar[] = {  //数码管显示字符转换表
0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07,
0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71
};

void delay();

void main()
{
bit keybuf = 1;  //按键值暂存，临时保存按键的扫描值
bit backup = 1;  //按键值备份，保存前一次的扫描值
unsigned char cnt = 0;  //按键计数，记录按键按下的次数

ADDR3 = 1;
ADDR2 = 0;
ADDR1 = 0;
ADDR0 = 0;
P2 = 0xf7; //P2.3置0，即KeyOut1输出低电平
P0 = LedChar[cnt]; //显示按键次数初值

      while (1)
{
      keybuf = KEY4;          //把当前扫描值暂存
      if (keybuf != backup)    //当前值与前次值不相等说明此时按键有动作
      {
         delay();             //延时大约10ms
         if (keybuf == KEY4) //判断扫描值有没有发生改变，即按键抖动
         {
            if (backup == 0)  //如果前次值为0，则说明当前是弹起动作
            {
                  cnt++;       //按键次数+1
                  if (cnt >= 10)
                  {          //只用1个数码管显示，所以加到10就清零重新开始
                     cnt = 0;
                  }
                  P0 = LedChar[cnt];  //计数值显示到数码管上
            }
            backup = keybuf;  //更新备份为当前值，以备进行下次比较
         }
      }
}
}
/* 软件延时函数，延时约10ms */
void delay()
{
unsigned int i = 1000;

while (i--);
}

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