scan_keyboard_driver.c

该压缩包内还有51单片机常用各类外设驱动C程序源码（128*64点阵屏

#include "AT89S52.H"
#include "CONFIG.H"
#include <intrins.h>
/******************************
		250US定时			  *
******************************/
#define RELOAD_H	0XFF		
#define RELOAD_L	0X19




bit bdata Key_Delay;
bit bdata Key_Read;
uchar data TIME_COUNT;
uchar data SUM;


//#define _BUZZER_
#ifdef _BUZZER_
sbit SPK=P2^7;//喇叭接口

void Delayms(uchar ms)
{							// 按键音延时子程序
	uchar i;
	while(ms--)
	{
		for(i = 0; i< 50; i++)
		{
			_nop_();
			
		}
	}
}

void Error_Beep()
{
uchar data  i;
     for(i=0;i<200;i++)
	    {
          SPK=~SPK;
			 delayms(5);
		 }

}

void Push_Beep()
{
uchar data i;
     for(i=0;i<200;i++)
	    {
          SPK=~SPK;
			 delayms(1);
		 }
}
#endif


#ifdef _TIMER1_
/****************************************************
		定时器1，方式1，定时250US					*
****************************************************/

void Key_Init()
{
IE|=0x88;		//EA=1;ET1=1;
TMOD=0x11;
TH1=RELOAD_H;
TL1=RELOAD_L;
TR1=1;
}



void time1() interrupt 3 using 1
{
uchar data x,y;
TH1=RELOAD_H;
TL1|=RELOAD_L;
     P1=0x0f;
     if(P1==0x0f)
	 	{
			Key_Delay=0;
			Key_Read=0;
			TIME_COUNT=0;
		
		}
else if(Key_Delay==0)
		{
			TIME_COUNT++;
			if(TIME_COUNT==100)
				Key_Delay=1;
		}
else if(Key_Read==0)
		{
			
     			 if(P1_0==0)  x=0;
			else if(P1_1==0)  x=4;
			else if(P1_2==0)  x=8;
			else if(P1_3==0)  x=12;
					P1=0xf0;
				 if(P1_4==0) y=0;
			else if(P1_5==0) y=1;
			else if(P1_6==0) y=2;
			else if(P1_7==0) y=3;
					SUM=(x+y);
					Key_Read=1;
		}

}

#else

/****************************************************
		定时器2，16位自动装载模式，定时250US		*
****************************************************/
void Key_Init()
{
IE|=0xA0;			//EA=1;ET2=1;
RCAP2H=RELOAD_H;
RCAP2L=RELOAD_L;
TH2=RELOAD_H;
TL2=RELOAD_L;
TR2=1;
}



void time2() interrupt 5 using 1
{
uchar data x,y;
TF2=0;
P1=0x0f;
     if(P1==0x0f)
	 	{
			Key_Delay=0;
			Key_Read=0;
			TIME_COUNT=0;
		
		}
else if(Key_Delay==0)
		{
			TIME_COUNT++;
			if(TIME_COUNT==100)
				Key_Delay=1;
		}
else if(Key_Read==0)
		{
			
     			 if(P1_0==0)  x=0;
			else if(P1_1==0)  x=4;
			else if(P1_2==0)  x=8;
			else if(P1_3==0)  x=12;
					P1=0xf0;
				 if(P1_4==0) y=0;
			else if(P1_5==0) y=1;
			else if(P1_6==0) y=2;
			else if(P1_7==0) y=3;
					SUM=(x+y);
					Key_Read=1;
		}
}

#endif