keyborad.c

上学时做的一个51单片机按键显示程序

/*
* Copyright(c)2005 - 2009 danise .China
* All rights reserved.
* Redistribution and use in source and bianry forms
* with or without modification ,are permitted provided
* that following conditions are met:
* 
* 1.Redistrubution of source code must retain the 
* above copyright notice,this list of conditions and
* following disclaimer.
* 
* 2.Redistributions in binary form must reproduce the 
* above copyright notice,this list of conditions and 
* following disclaimer in the documentation and /or other
* materials provided with the distribution.
* 
* Alternately, this acknowledgment may appear in the software
* itself,if and wherever such third-party acknowledgements
* normally appear.
*
* This software is designed for key board and led display.
* 
	
*/
#include"include/keyboard.h"
#include "include/datatypes.h"
#include "include/display.h"
#include "include/global.h"
#include "include/system.h"
/** get key but not a safe key 
  using P0 port
*/

UINT8 keyok = 0;
UINT8 keyage = 0; /* */
UINT8 oldkey = 0 ;
UINT8 Scankey(void)
{
	UINT8 tempkeycode=0xff;	
	UINT8 AA;
	UINT8 BB;
	P0=0x0f;
	AA=P0;
	AA&=0x0f;
	BB=AA;
	P0=0x0f0;
	AA=P0;
	AA&=0xf0;
	tempkeycode=AA|BB;
	return tempkeycode;			   	

}
/*
*/
INT8 GetSafeKeyValue()
{
	UINT8 idata temp;
	INT8 idata rKeyVal;
	temp = Scankey();
	if(0xff!=temp){
		if(!( temp^oldkey )){/* if same */
			oldkey = temp;
			keyage ++;
			if(! keyok ){ /* never response */
				if( keyage == 3 ){
					switch ( temp )
					{	
						case 0x77:	rKeyVal=0; break;
						case 0xBD:	rKeyVal=1; break;
						case 0xBB:	rKeyVal=2; break;
						case 0xB7:	rKeyVal=3; break;
						case 0xED:	rKeyVal=4; break;
						case 0xEB:	rKeyVal=5; break;
						case 0xE7:	rKeyVal=6; break;
						case 0xDD:	rKeyVal=7; break;
						case 0xDB:	rKeyVal=8; break;
						case 0xD7:	rKeyVal=9; break;
						case 0x7B:	rKeyVal=10; break;//"."
						case 0x7D:	rKeyVal=11; break;//"BACK"
						case 0xDE:	rKeyVal=12; break;//"CLEAR ALL"
						case 0xEE:	rKeyVal=13; break;//"+"
						case 0xBE:	rKeyVal=14; break;//"*"
						case 0x7E:	rKeyVal=15; break;//"enter"
						default:	rKeyVal=-1;	
					}
				 keyok = 1;
				 keyage = 0;
				 /* do your work ** begin **with key value */
				 /* clr crc save */
	 			 sreensaveclk = 0;
	 			 scrflag = 0;
			     return rKeyVal ;
				 /*  ** end ** */					
				}
				else{ /*key age is not old enough */
					return (-1);
				}


			}
			else{ /* responsed */
				return (-1);
			}
		}
		else{/* if different */
			keyok = 0;
			keyage = 0;
			oldkey = temp;
			return (-1);
		}
		
	}
	else{
		keyok = 0;
		keyage = 0;
		return (-1);
	}

	
}
void AnalyseKeyVal(UINT8 keyVal )
{
	
	if (keyVal <0) return; /* no key press */
	if(keyVal>=0 && keyVal<=0xa ){
	/* data key value */
		addKyeValHexBuf( keyVal );
	}
	else{//>0
	/* cmd key value*/
	/*
		1. LEDS process
		2. I2C	process
	*/
		switch ( keyVal )
		{
			case 11:  backspace(); break;
			case 12:  clearallleds();break;
			case 15:  enter();break;
		
		}
	}
	
}