4x4矩阵式键盘识别.txt

4X4矩阵式键盘识别程序

#include <REGX51.H>

//数码管上显示的0-9的显示代码
unsigned char code LEDCODE[]=
{
  //0   1    2    3    4
  0x3f,0x06,0x5b,0x4f,0x66,
  //5   6    7    8    9
  0x6d,0x7d,0x07,0x7f,0x6f,
  //A      b    C        d         E      F
  0x77,0x7c,0x39,0x5e,0x79,0x71,
};

//对于22.1184MHz晶振延时5mS子程序
void Key_Delay(void)
{
  unsigned char i,j;

  for(i=20;i>0;i--)
  for(j=248;j>0;j--);
}

void main(void)
{
  unsigned char key;

  while(1)
    {
      P1=0xef;//扫描第一列
      if ((P1 & 0x0f)!=0x0f)//判断是该列是否有键按下
        {
             Key_Delay();//去抖动
          if ((P1 & 0x0f)!=0x0f)//再判断该列是否有键按下
            {
              switch(P1 & 0x0f)//读取行的代码，分析是哪一行有键按下
                {
                  case 0x0e:
                    key=7;
                    break;
                  case 0x0d:
                    key=4;
                    break;
                  case 0x0b:
                    key=1;
                    break;
                  case 0x07:
                    key=10;
                    break;
                }
              P0=LEDCODE[key];//送出显示
              while((P1 & 0x0f)!=0x0f);//等待按键释放
            }
        }

      P1=0xdf;//扫描第二列
      if ((P1 & 0x0f)!=0x0f)
        {
             Key_Delay();
          if ((P1 & 0x0f)!=0x0f)
            {
              switch(P1 & 0x0f)
                {
                  case 0x0e:
                    key=8;
                    break;
                  case 0x0d:
                    key=5;
                    break;
                  case 0x0b:
                    key=2;
                    break;
                  case 0x07:
                    key=0;
                    break;
                }
              P0=LEDCODE[key];
              while((P1 & 0x0f)!=0x0f);
            }
        }

      P1=0xbf;//扫描第三列
      if ((P1 & 0x0f)!=0x0f)
        {
             Key_Delay();
          if ((P1 & 0x0f)!=0x0f)
            {
              switch(P1 & 0x0f)
                {
                  case 0x0e:
                    key=9;
                    break;
                  case 0x0d:
                    key=6;
                    break;
                  case 0x0b:
                    key=3;
                    break;
                  case 0x07:
                    key=11;
                    break;
                }
              P0=LEDCODE[key];
              while((P1 & 0x0f)!=0x0f);
            }
        }

      P1=0x7f;//扫描第四列
      if ((P1 & 0x0f)!=0x0f)
        {
             Key_Delay();
          if ((P1 & 0x0f)!=0x0f)
            {
              switch(P1 & 0x0f)
                {
                  case 0x0e:
                    key=12;
                    break;
                  case 0x0d:
                    key=13;
                    break;
                  case 0x0b:
                    key=14;
                    break;
                  case 0x07:
                    key=15;
                    break;
                }
              P0=LEDCODE[key];
              while((P1 & 0x0f)!=0x0f);
            }
        }
                   
     }
}