keyboard.c

键盘扫描C程序,希望对大家有用

#include<reg51.h>
#include<stdio.h>
#include<stdlib.h> 
#include<intrins.h>
#include<absacc.h>

#define uchar unsigned char
#define uint unsigned int
#define nop _nop_()

sbit pc=P2^0;
sbit pd=P2^1;

code uchar table[16]={0xfc,0x60,0xda,0xF2,0x66,
                      0xB6,0xBE,0xE0,0xFE,0xf6,
					  0x10,0x11,0x12,0x13,0x14,0x15};
uchar keycode;
	//----------------------------------------------
	void sendData(char c)
	{
		char i;
		bit temp;
		c=~c;
		for(i=0;i<8;i++)
 	    {
		  if (c&0xfe==0xfe) temp=0;
		  else temp=1;

		  pc=0;
		  pd=temp;
		  pc=1;

		  c>>=1;
		}
	}
//---------------------------------
void delay2ms()
{
  uchar t=255;
  while(t--);
  t=52;
  while(t--);
}
//---------------------------------
void delay10ms()
{
  uchar i=5;
  while(i--) delay2ms();
}
//---------------------------------
void detectkey(void)
{
  uchar key,line,col;

  P1=0xf0;
  key=P1&0xf0;
  if(key!=0xf0)
  {
    delay10ms();
	P1=0xf0;
    key=P1&0xf0;
	if(key!=0xf0) //confirm
    {
	  if(key==0xe0) line=0;
	  if(key==0xd0) line=1;
      if(key==0xb0) line=2;
      if(key==0x70) line=3;

	  P1=0xfe;
	  key=P1&0xf0;          
      if(key!=0xf0) col=0;

	  P1=0xfd;
 	  key=P1&0xf0;
	  if(key!=0xf0) col=1;

      P1=0xfb;
	  key=P1&0xf0;
	  if(key!=0xf0) col=2;
	  
      P1=0xf7;
	  key=P1&0xf0;
	  if(key!=0xf0) col=3;

      keycode=(line*4+col);
	  sendData(table[keycode]);

      P1=0xf0;
      key=P1&0xf0;
      while(key!=0xf0)
      {
        P1=0xf0;
        key=P1&0xf0;
      };//wait until release
    }
  }
}
//==================================
void main(void)
{
  while(1) detectkey(); 
}