yampp3.c

yampp的MP3资料 非常好大家来看一看

//////////////////////////////////////////////////////////////////
// B - Port
//////////////////////////////////////////////////////////////////

	sbi(PORTB, 0);	// DIOW- hi
	sbi(DDRB, 0);	// pin PB0 is output, DIOW- 

	sbi(PORTB, 1);	// DIOR- hi
	sbi(DDRB, 1);	// pin PB1 is output, DIOR- 

	cbi(DDRB, 2);	// pin PB2 is input, DEMAND
	sbi(PORTB, 2);	// activate pullup

	// PB3 and PB4 is used for BSYNC and MP3 signals to VS1001

	// PB5 (MOSI) is used for SPI
	// PB6 (MISO) is used for SPI
	// PB7 (SCK) is used for SPI

//////////////////////////////////////////////////////////////////
// D - Port
//////////////////////////////////////////////////////////////////

	// PD0 and PD1 are TX and RX signals

	// PD2 is used for the IR receiver

	cbi(DDRD, 3);	// pin PD3 is keyboard input

	// PD4 is available
	
	// PD5 is LCD_ENABLE used by LCD module

	// PD6 and PD7 are RD and WR signals
	// but we need to set their default states used
	// when the external memory interface is disabled
    // they should then both be high to avoid disturbing
	// RAM contents
	
	sbi(DDRD, 6);		// as outputs
	sbi(DDRD, 7);

	sbi(PORTD, 6);		// and both hi
	sbi(PORTD, 7);


//////////////////////////////////////////////////////////////////
// Timer 1
//////////////////////////////////////////////////////////////////

	//
	// setup timer1 for a 100mS periodic interrupt
	//	
	
	outp(0, TCCR1A);
	outp(4, TCCR1B);		// prescaler /256  tPeriod = 32 uS
	outp(TI1_H, TCNT1H);	// load counter value hi
	outp(TI1_L, TCNT1L);	// load counter value lo


 //----------------------------------------------------------------------------
 // 
 //----------------------------------------------------------------------------

    lcd_init(0, LCD_FUNCTION_DEFAULT); 	// also sets up EXTRAM pins


	//
	// construct some user definable characters
	//
	userchars();
	
	//
	// show a '*' in all display positions, then clear
	// screen and display a welcome message
	//
	for (c=0;c<17;c++)
	{
		lcd_gotoxy(c,0);
		lcd_putchar('*');
		delayms(10);
	}
	for (c=16;c>0;c--)
	{
		lcd_gotoxy(c,1);
		lcd_putchar('*');
		delayms(10);
	}
	lcd_clrscr();
	lcd_puts(" yampp-3  Alive ");
	

	UART_Init();		// init RS-232 link

	vs1001_init_io();	// init

	init_rec80();		// set up IR receiver interface


	// setup some buffers
	SectorBuffer = (u08 *) SECTOR_BUFFER;	// 512 byte
	buffer1 = (u08 *) BUFFERSTART;			// 3 clusters, 12 k
	buffer2 = (u08 *) buffer1 + BUFFERSIZE;	// 3 clusters, 12 k
	buffer3 = (u08 *) buffer2 + BUFFERSIZE;	// end pointer


	// say hello
  	PRINT("yampp-3  ");
	UART_Puts(__DATE__);
	PRINT(" ");
	UART_Putsln(__TIME__);
	EOL();


//  	delayms(5);		// 5 mS

	// init VS1001
	vs1001_init_chip();

	// Init and wait for drive
  	WriteBYTE(CMD, 6, 0xA0); // Set drive/Head register, ie. select drive 0
    while ( (ReadBYTE(CMD,7) & (SR_BUSY|SR_DRDY)) == SR_BUSY ); // Wait for DRDY and not BUSY
  	PRINT("Ready!\r\n");

	// init randomizer from timer
	seed = 1 + inp(TCNT1L);

	// reset drive 
	ATA_SW_Reset();

	// read structures
	init_fat(DRIVE0);



	// load and set default volume
//	volume = eeprom_rb(EEPROM_VOLUME);
//	vs_1001_setvolume(volume,volume);

	volume = 12;		// -6 dB
	setvolume(volume);

	// Send three sinewave beeps to indicate we're starting up okay
	send_sinewave_beeps();


//
// TESTCODE to get number of songs on disk
//	
 	PRINT("Scanning... \r\n");

//	last_song = dirlist(DIRLIST_VERBOSE);
	last_song = dirlist(DIRLIST_SCAN);

 	PRINT("Found ");
	UART_Printfu16(last_song);
	PRINT(" Entries\r\n");
//
// END TESTCODE
//	


	// load autoplay and position settings
	autoplay = eeprom_rb(EEPROM_AUTOPLAY);
	dentry 	 = eeprom_rb(EEPROM_SONGPOS);	


	if (autoplay)
		event = EV_PLAY;




///////////////////////////////////////////////////////////////////////////////
// start things rolling
///////////////////////////////////////////////////////////////////////////////


	// enable timer1 interrupt
	sbi(TIMSK, TOIE1);	 	


	//
	// main loop
	//

  	while (1) 
  	{
		
		if (UART_HasChar())
			event = get_char_event();

		if (rec80_active)
			event = ir_event();


		if (event == EV_IDLE)
			event = get_key_event();



		switch (event)
		{
			default:
			case EV_IDLE: 
				break;

				
			case EV_PREV:
				dentry-=2;	
				if ((int)dentry <= -2)
					dentry = (u16)-1;

				// fall through		

			case EV_NEXT:
				dentry++;

				// fall through

			case EV_PLAY:

				lcd_clrscr();

				vs1001_reset();

				eeprom_wb(EEPROM_SONGPOS,dentry);

				// setup for play
				cli();
				filesize = get_dir_entry(dentry);
				sei();
				
				if (filesize == 0)	// no more
				{	
					// wrap
					dentry = 0;
					cli();
					get_dir_entry(dentry);
					sei();
				}	

				filesize = get_filesize() / 32;
				
				barsize = (u16) ((u32) filesize / 40);
				barstep = 0;
				filepos = 0;

				// start playing
				PRINT("\r\nPlaying #"); UART_Printfu08(dentry); UART_SendByte(' ');
				UART_Puts( get_dirname() ); 
				UART_Putsln( (p = get_filename()) );
								
				scroll_line = q = p;
				scroll_pos = 0;
				scroll_length = 0;

				while (*q++)
					scroll_length++;
				q--;
				*((u32*)q)++ = 0x207E7F20L;
				*q++ = 0;
				scroll_length += 4;

			    // preload buffers
			    
			    cli();
			    for (i=0;i<BUFFERSIZE*2;i+=0x1000)
					load_sectors(buffer1 + i);
				sei();

			    outptr = buffer1;
				isPlaying = 1;
				updbuf = 0;
				p_time = 0;
				scroll_flag = 0;
				time_flag = 0;


				// special MP3 header patch to strip
				// all invalid headers 
				{
					u16 i=0;
					
					while ( ( (*(u16 *)(outptr)) & 0xfeff) != 0xfaff ) 
					{
		    			*outptr++ = 0;
	    				if (i++ > 1000)
	    					break;
					}
				    outptr = buffer1;
				}
				/* end of special header patch */

				event = EV_IDLE;
				break;					

			case EV_STOP:
				isPlaying = 0;
				event = EV_IDLE;
				break;				

			case EV_VOLDN: 
				if (volume < 0xfe) volume++; 
				setvolume(volume);
				break;

			case EV_VOLUP: 
				if (volume > 0) volume--; 
				setvolume(volume);
				break;

			case EV_NEUTRAL: 
				volume = 12;		// -6 dB
				setvolume(volume);
				break;
/*
			case EV_MUTE:
				mute = 1-mute;
				break;
*/
		}
	
		// we always go back to IDLE
		// when exiting switch
		event = EV_IDLE;
	
	
		// time to update a buffer ?
		if (updbuf)
		{
			cli();
		    for (i=0;i<BUFFERSIZE;i+=0x1000)
				load_sectors(updbuf + i);
			sei();			    
			updbuf = (u08 *) 0;			// mark as done
		}
		
		if (isPlaying)
		{
			// pump some data to the decoder
			
			while ( bit_is_set(PINB, PB2) )			// while DREQ is hi 
			{
			
				//send data on SPI bus
				vs1001_send_32(outptr);
				outptr += 32;

				// check for buffer wrap
				if (outptr == buffer2)
					updbuf = buffer1;
				else if (outptr == buffer3)
				{
					updbuf = buffer2;
					outptr = buffer1;
				}

				// check if we're done
				filesize--;
				
				if (barstep++ == barsize)
				{
					filepos++;
					barstep = 0;
				}

				if (filesize <= 0)
				{
					isPlaying = 0;					// the end is near 
					// try autoplay next song
					
					if (random)
					{
						dentry = rand();
						dentry = dentry % last_song;
						event = EV_PLAY;
					}
					else
					{
						event = EV_NEXT;
					}
					PRINT("done\r\n");
					break;
				}
			}
			
			// scroll display every 300 ms
			if (scroll_flag >= 3)
			{
				lcd_gotoxy(0,0);
				
				for (c=0;c<16;c++)
					lcd_putchar( scroll_line[ (scroll_pos+c) % scroll_length ] );
				scroll_pos++;
				scroll_flag = 0;
			}    

			// update timer every 500mS
			if (time_flag >= 5)
			{

				dispbar(filepos);
			
				p = SectorBuffer;

				i = p_time / 10;	// seconds
			
				*p++ = '0' + (i / 3600);
				i %= 3600;

				*p++ = ':';
				
				*p++ = '0' + (i / 600);
				i %= 600;
				*p++ = '0' + (i / 60);

				*p++ = ':';

				i %= 60;
				*p++ = '0' + (i / 10);
				i %= 10;
				*p++ = '0' + i;			

				*p++ = 0;

				lcd_gotoxy(8,1);				
				lcd_puts(SectorBuffer);
				lcd_putchar(0);	// volume indicator
				time_flag = 0;
			}

		}//if (isPlaying)

  	}    
}