lpc_lib_keyboard.c

使用embest IDE开发工具开发的基于LPC2294 的触摸屏开发

/***********************************************************************

       Embest Info&Tech Co., Ltd.  All rights reserved.
                     www.embedinfo.com

file     : 
author   : embest 
establish: 2006.
modify	 :
notes    :
***********************************************************************/

/*-------------------------------------------------------------------*/
/*                       include files                               */
/*---------------------------------------------------------------- --*/

#include	"..\..\com\lpc_lib_keyboard\lpc_lib_keyboard.h" 
/*-------------------------------------------------------------------*/
/*              extern function/variable declare                     */
/*-------------------------------------------------------------------*/
void irq_eint3_svr(void);
extern irq_eint3(void);


/*-------------------------------------------------------------------*/
/*                      global variable define                       */
/*-------------------------------------------------------------------*/

INT32U key_data=255;	

/*-------------------------------------------------------------------*/
/*                       function code                               */
/*-------------------------------------------------------------------*/
/*
**********************************************************************************************
* name:		key_init
* func:		initialize keyboard function
* para:		none
* ret:		none
* modify:
* comment:		
**********************************************************************************************
*/
void key_init(void)
{
	INT32U i;
	
	PINSEL2 &=0xFFFFFFF7;					//initialize the matrix key	 
	IODIR1 |=0x00F00000;
	IOCLR1 |=0x00F00000;	
		  	 	  
	IODIR0&=0xBFFFFFFF;					//before set pin to eint3,must set the pin sate
	PINSEL1&=0xCFFFFFFF;
	 	
	i=PINSEL1;       						//select eint3 pin
	i &=0xCFFFFFFF;
	i |=0x20000000;
	PINSEL1=i;
 		
	VICVectCntl4 = 0x31;					//17th channel  110001	
	VICVectAddr4 = (INT32U)irq_eint3;	
	VICIntEnable |= 0x00020000;	
}
/*
**********************************************************************************************
* name:		key_close
* func:		disable 4*4 keyboard,close key interrupt
* para:		none
* ret:		none
* modify:
* comment:		
**********************************************************************************************
*/
void key_close(void)
{	
	PINSEL2 &=0xFFFFFFF7;					//restore reset value	 
	IODIR1 &=0xFF00FFFF;					
	IOCLR1 &=0xFF00FFFF;	
		  	 	  
	IODIR0 &=0xBFFFFFFF;					//restore reset value
	PINSEL1&=0xCFFFFFFF;
	
	VICVectCntl4 = 0x0;						//close int. channel	
	VICVectAddr4 = 0x0;	
	VICIntEnable &= 0xFFFDFFFF;	
}	
	
	
/**************************eint3 svr***********************************
Desc:The scan key interrupt service routine,after finish the scan action,put key 
	value to global variable "key_data".
---0-----1-----2-----3------
---4-----5-----6-----7------line
---8-----9-----a-----b------
---c-----d-----e-----f------
  			column       
***********************************************************************/	  
void irq_eint3_svr(void)
{	
	key_data=key_read();
	EXTINT=0x08;
	VICVectAddr=0;
}	  

/*
**********************************************************************************************
* name:		key_read
* func:		when enter key interrupt,this routine get key value 
* para:		none
* ret:		none
* modify:
* comment:	scan line and column,get the key value	
**********************************************************************************************
*/	  
INT8U key_read(void)
{
	INT32U i;								//column scan parameter,4 times						
	INT32U j=4;								//line scan parameter,4 times
	INT32U temp=0x00100000;					//column scan value (1,  2,  4, 8)
	INT32U temp1=0x00010000;				//line scan value	
	INT8U data=3;							//key value
	for(i=0;(i<4)&&(j==4);i++)						//column scan cycle
	{											
		IOCLR1 |=temp;						//clear the pin that scaned follow
		IOSET1 |=0x00F00000-temp;			//set non-scan pin
		for(j=0,temp1=0x00010000;j<4;j++)	//line scan cycle
		{
			if((IOPIN1&temp1)==0)			
			{	data=data+j*4-i;			//see the pressed key,compute key value
				break;						//jump out cycle
			}
			temp1=temp1<<1;					//turn next pin,also next line
		}
		temp*=2;							//scan next colmn
	}
	
	while((IOPIN1&0x000f0000)!=0x000f0000);	//wait till the key release
	time_dly(20);							//stability dealy	
	IODIR1 |=0x00F00000;					//restore key bin for next int.
	IOCLR1 |=0x00F00000;

	if(data<16)
		return data;
	else
		return 255;

}
/*
**********************************************************************************************
* name:		get_key
* func:		wait for key value change ,then return latest key value
* para:		none
* ret:		key value
* modify:
* comment:		
**********************************************************************************************
*/
INT8U get_key(void)
{
	INT8U key;
	while(key_data>15);
	key=key_data;
	key_data=255;
	return key;
}
/*
**********************************************************************************************
* name:		moni_key
* func:		watch key interrupt ,return the result
* para:		none
* ret:		1: indicate that key was pressed  0:none key pressed
* modify:
* comment:		
**********************************************************************************************
*/
INT8U moni_key(void)
{
	if(key_data<16)
	{
		key_data=255;
		return 1;
	}
	else
		return 0;
}