key.c

单片机按键程序,本人自己编写,希望对大家有参考价值

#include<reg51.h>
unsigned char key,key_h,kpush;
unsigned int key_1;
//按键连接到p1.0,p1.1,p1.2

void int_t0(void) interrupt 1 using 1
{
	TLO=TL0+30;
	TH0=Oxfb;//800
     if((P1&0x7==0x7)/*按键判别*/
	{
	if((key_1>30)&&(key_1<800)&&(key_h>30))
	{key=kpush;}
     if((++key_h)>200)key_h=200;
	key_1=0;
     if(key>=0x80)key=0;
        }
     else
	{
	 kpush=P1&0x7;
	 key_1++;
	if((key_1>800)&&(key_h>30)) 
	{
	  key=kpush|0x80;
	  key_h=0;
	  key_1=0;
	}
        }
}
void main(void)
{
  TMOD=0x1;
  TR0=1;
  ET0=1;
  EA=1;
  while(1)
  {
    while(!key){}
   switch(key)
     { 
       case 1: break;
       case 2: break;
     }
  }
}






#include<reg51.h>
#define uchar unsigned char
#define uint unsigned int
void delay(void);
uchar keyscan();
void getkey(void)
{ uchar key;
  while(1)
{key=keyscan();
 delay();
}
}
void delay(void)
{ uchar i;
   for(i=0;i<200;i++){}
}
uchar keyscan(void)
{
	uchar code_h;
	uchar code_l;
	P1=0xf0;
	if((P1&0xF0)!=0xF0)
     {
       delay();
       if(P1&0xF0)!=0xF0)
	{
	  code_h=0xFE;
	  P1=code_h;
	  while((P1&0xF0)!=0xF0)
{
if(P1&0xF0)!=0xF0)
{
	code_l=(P1&0xF0|0x0F);
       return((~code_h)+(~code_l));
}
  else
     code_h=(code_h<<1)|0x01;
}
}
}
return(0);                                     //无按键
}

在C语言中嵌入汇编语句
#pragram  asm
汇编行
#pragram  endasm