/**	@file	button.h	@brief	Butterfly MP3 Button Handling	@author	Nick Lott 	@date	January 2005	Copyright (C) 2005 Nick Lott <nick_Lott@bigfoot.com>		This is a simple MP3 player based around the AVR Butterfly.It currently 	uses a VS1001 mp3 decoder, MMC card and Nokia LCD. It has been heavily 	influenced by the Yampp system by Jesper Hansen <jesperh@telia.com>.		This program is free software; you can redistribute it and/or	modify it under the terms of the GNU General Public License	as published by the Free Software Foundation; either version 2	of the License, or (at your option) any later version.	This program is distributed in the hope that it will be useful,	but WITHOUT ANY WARRANTY; without even the implied warranty of	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the	GNU General Public License for more details.	You should have received a copy of the GNU General Public License	along with this program; if not, write to the Free Software Foundation, 	Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.	Target(s)...: ATmega169	Compiler....: AVR-GCC 3.3.1; avr-libc 1.0	**//// Button masks for pin change interupt handling.#define PINB_MASK ((1<<PINB4)|(1<<PINB6)|(1<<PINB7))#define PINE_MASK ((1<<PINE2)|(1<<PINE3))/// Button Hardware definitions#define BUTTON_A    6   ///< UP#define BUTTON_B    7   ///< DOWN#define BUTTON_C    2   ///< LEFT#define BUTTON_D    3   ///< RIGHT#define BUTTON_O    4   ///< PUSH/// Button logical definitions ( virtual keys)#define KEY_NULL    0#define KEY_ENTER   1#define KEY_NEXT    2#define KEY_PREV    3#define KEY_PLUS    4#define KEY_MINUS   5void PinChangeInterrupt(void);void Button_Init(void);char getkey(void);char ButtonBouncing(void);