麻烦高手帮忙看下键盘扫描的问题

只看该作者 · 2011-6-19 14:54

#include <reg51.h>
#include <intrins.h>

sbit rs=P2^0;
sbit rw=P2^1;
sbit en=P2^2;

#define uchar unsigned char
#define uint  unsigned int

uint key;
uchar code1[]={"0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,-"};
uchar code2[]={" Key number "};
uchar code3[]={" key code:-  H "};

void delay_1ms(uint n)
{
uint i,j;
for(i=0;i<n;i++)
   for(j=0;j<125;j++);
}

void write_cmd(uchar cmd)
{
  rs=0;
  rw=0;
  en=1;
  P0=cmd;
  delay_1ms(20);
  en=0;

}
void write_dat(uchar dat)
{
  rs=1;
  rw=0;
  en=1;
  P0=dat;
  delay_1ms(20);
  en=0;

}

void lcd_init()
{
en=1;
write_cmd(0x38);
delay_1ms(10);
write_cmd(0x0c);
delay_1ms(10);
write_cmd(0x06);
delay_1ms(10);
write_cmd(0x01);
delay_1ms(10);
en=0;
}

void keyscan()
{
  uchar temp,sem1,sem2;
  P1=0xf0;
  temp=P1;
  if(temp!=0xf0)
{
   delay_1ms(15);
   if(temp!=0xf0)
      sem1=temp&0xf0;
   P1=0x0f;
   delay_1ms(1);
   temp=P1;
   sem2=temp&0x0f;
   temp=sem1|sem2;
}
switch(temp)
{
case 0xee : key=0; break;
case 0xde : key=4; break;
case 0xbe : key=8; break;
case 0x7e : key=12;  break;
case 0xed : key=1; break;
case 0xdd : key=5; break;
case 0xbd : key=9; break;
case 0x7d : key=13;  break;
case 0xeb : key=2; break;
case 0xdb : key=6; break;
case 0xbb : key=10;  break;
case 0x7b : key=14;  break;
case 0xe7 : key=3; break;
case 0xd7 : key=7; break;
case 0xb7 : key=11;  break;
case 0x77 : key=15;  break;
default : key=16;  break;

}
}

void main()
{
  uint k;
  lcd_init();
  delay_1ms(10);
  write_cmd(0x80);
  for(k=0;k<16;k++)
   {
      write_dat(code2[k]);
      delay_1ms(10);
   }
  write_cmd(0x80+0x40);
  for(k=0;k<16;k++)
   {
      write_dat(code3[k]);
      delay_1ms(10);
   }

  while(1)
  {
  keyscan();
  delay_1ms(1);
  write_cmd(0x80+0x4d);
  delay_1ms(2);
  write_dat(code1[key]);
  delay_1ms(10);
  }

}