51单片机4*4键盘的程序设计方法

              switch(temp)
                {
                  case 0x0e:
                    key=1;
                    break;
                  case 0x0d:
                    key=2;
                    break;
                  case 0x0b:
                    key=3;
                    break;
                  case 0x07:
                    key=12;
                    break;
                }
              temp=P3;
              P1_0=~P1_0;
              P0=table[key];
              temp=temp & 0x0f;             
              while(temp!=0x0f)
                {
                  temp=P3;
                  temp=temp & 0x0f;             
                }
            }
        }
      P3=0xff;
      P3_7=0;
      temp=P3;
      temp=temp & 0x0f;
      if (temp!=0x0f)
        {
          for(i=50;i>0;i--)
          for(j=200;j>0;j--);
          temp=P3;
          temp=temp & 0x0f;
          if (temp!=0x0f)
            {
              temp=P3;
              temp=temp & 0x0f;             
              switch(temp)
                {
                  case 0x0e:
                    key=0;
                    break;
                  case 0x0d:
                    key=13;
                    break;
                  case 0x0b:
                    key=14;
                    break;
                  case 0x07:
                    key=15;
                    break;
                }
              temp=P3;
              P1_0=~P1_0;
              P0=table[key];
              temp=temp & 0x0f;             
              while(temp!=0x0f)
                {
                  temp=P3;
                  temp=temp & 0x0f;             
                }
            }
        }
    }
}

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本文关键字：单片机  程序设计  键盘  51单片机，单片机-工控设备 - 51单片机