trykeyboard1.c

此程序为4*4行列式键盘扫描程序

        #include<reg52.h>
		#define unit unsigned int
		#define uchar unsigned char
		void delay();
		void BeepCount (uchar x);
		uchar KeyDown(void);
		uchar KeyUp(void);
		uchar KeyNum(void);
		#define BEEP_ON() (P1_3=0)
		#define BEEP_OFF() (P1_3=1)

		sbit P1_3=P1^3;
		sbit row1=P2^7;
		sbit row2=P2^6;
		sbit row3=P2^5;
		sbit row4=P2^4;
		sbit col1=P2^3;
		sbit col2=P2^2;
		sbit col3=P2^1;
		sbit col4=P2^0;
		
	   //void BeepCount(uchar count) ;
       void main (void)                
       {
                 
       BEEP_OFF();              // 蜂鸣器不蜂鸣

       while(1)                                                 // 死循环
      {

       BeepCount(KeyNum());	  //function clarify 函数格式声明
      }  					 
       }

  void BeepCount(uchar count)
 {
  for(;count>0;count--)
     {
       BEEP_ON(); delay();
       BEEP_OFF();delay();
     }
  }


		 uchar KeyNum(void)
		  {

		    uchar KeyTemp;

			KeyTemp=0;
			if(KeyDown()==1)
			{

			  col1=0;					 //colmn one
			  col2=1;
			  col3=1;
			  col4=1;
			  if(row1==0) KeyTemp=1;
			  if(row2==0) KeyTemp=5;
			  if(row3==0) KeyTemp=9;
			  if(row4==0) KeyTemp=13;


			  col1=1;				   //colmn two
			  col2=0;
			  col3=1;
			  col4=1;
			  if(row1==0) KeyTemp=2;
			  if(row2==0) KeyTemp=6;
			  if(row3==0) KeyTemp=10;
			  if(row4==0) KeyTemp=14;


			  col1=1;				  //colmn three
			  col2=1;
			  col3=0;
			  col4=1;
			  if(row1==0) KeyTemp=3;
			  if(row2==0) KeyTemp=7;
			  if(row3==0) KeyTemp=11;
			  if(row4==0) KeyTemp=15;


			  col1=1;
			  col2=1;
			  col3=1;
			  col4=0;
			  if(row1==0) KeyTemp=4;
			  if(row2==0) KeyTemp=8;
			  if(row3==0) KeyTemp=12;
			  if(row4==0) KeyTemp=16;

			  while(KeyUp()!=1);
			  return KeyTemp;
			  
			  }
			  else
			   return 0;
			}



		 uchar KeyDown(void)		  //键盘按下函数
		 {

		    col1=0;
			col2=0;
			col3=0;
			col4=0;
			if(row1==0||row2==0||row3==0||row4==0)
			{

			  delay();
			  if(row1==0||row2==0||row3==0||row4==0)
			  return 1;
			else
			  return 0;
			}
			else 
			  return 0;
		  }


		 uchar KeyUp(void)	  //键盘弹起函数
		 {

		   col1=0;
		   col2=0;
		   col3=0;
		   col4=0;
		   if(row1==1&&row2==1&&row3==1&&row4==1)
		   {

		     delay();
			 if(row1==1&&row2==1&&row3==1&&row4==1)
			 return 1;
		  else
		     return 0;
			}
		  else
		     return 0;
		  }

		  

		  void delay ()	//delay function
		  {

		  unit i;
    	 // while(--count!=0)
		    //{
		 	   for(i=0;i<125;i++);

		//	}
		}