keyboard.c

该软件为在sunplus的６１单片机上实现的mp3播放器．里面有完整的源代码．

#include "..\\spce061\\061reg.h"
#include "keyboard.h"
// This Valume User Extern 
unsigned int keyEvent;
// This Program User
static unsigned int keyTimer, xrefTimer, currentKey=KEY_NONE, lastKey=KEY_NONE;
/*
	keyEvent Ret KeyValue:
	000X is First Press Key
	400X is Release Key
	800X is Second Function Key or Rep Key
*/
void KeyEvent()
{// 50MS Once Event
	static unsigned int repKey=0;
	currentKey= KeyScan();
	if( currentKey != KEY_NONE )
	{// New Key Press or Re-Press Key
		if( currentKey != lastKey)
		{// New Key Press (First Press Key)
			keyEvent= currentKey;
			repKey=0;
			keyTimer= 0x00;
			xrefTimer= 0x1f;		// 1.5 Sec
		}
		else
		{// Re Press Key
			if( ++keyTimer > xrefTimer )
			{
				repKey= 1;
				keyEvent = 0x8000 | currentKey;
				keyTimer=  0x00;				
				xrefTimer= 0x15;	// 1.0 Sec
			}
		}
	}
	else
	{// KEY NONE
		if((lastKey != KEY_NONE) && (repKey != 1))
		{			
			keyEvent=lastKey | 0x4000;
		}
		else
		{
			keyEvent= KEY_NONE;
		}
		repKey=0;
		keyTimer=0x00;
		xrefTimer=0x1f;
	}
	lastKey=currentKey;
}

unsigned int KeyScan()
{
	unsigned int max, min, k, i;
	InitAD();
	do
	{		
		//Set Max & Min 
	 	max= 0x0000;
	 	min= 0xFFFF;
	 		 
	 	for(k= 0; k < 3; k++) 
	   	{
	   		*P_Watchdog_Clear=C_WDTCLR;
	   		i = GetAD();			   	
	   		i >>= 4;	
	    	if(i > max) max= i;
	    	if(i < min) min= i;
	   	}
	}	   
	while( (max-min) > 0x020);

    i= ((max + min) / 2) + 1;

	if		( i > KEY_NONE_VALUE )			k= KEY_NONE;
	else if ( i > KEY_VOLUME_INC_VALUE )	k= KEY_VOLUME_INC;
	else if ( i > KEY_VOLUME_DEC_VALUE )	k= KEY_VOLUME_DEC;
	else if ( i > KEY_FF_VALUE )			k= KEY_NEXT;
	else if ( i > KEY_STOP_VALUE )			k= KEY_STOP;
	else if ( i > KEY_FR_VALUE )			k= KEY_LAST;
	else if ( i > KEY_AB_VALUE )			k= KEY_AB;
	else if ( (i > KEY_PLAY_VALUE - 0xc5) && (i < KEY_PLAY_VALUE + 0xc5) )	k= KEY_PLAY;
	else                                    k= KEY_NONE;
	return(k);
}

unsigned int GetAD(void)
{
	unsigned int uiData;
	while(!(*P_ADC_MUX_Ctrl&0x8000)); 	//wait,until ADC complete
	uiData=*P_ADC_LINEIN_Data;
	return(uiData&0xffc0);
}

void InitAD()
{
	*P_ADC_MUX_Ctrl=C_ADC_CH1; 			//LINE_IN-------IOA0
	*P_ADC_Ctrl= C_ADCE; 				//ADC enable
}	

void KeyInit()
{
	*P_TimerB_Ctrl=C_SourceC_4096Hz;
	*P_TimerB_Data=0xff32;
	*P_INT_Ctrl=C_IRQ2_TMB;
	IRQ_ON();
}