mp3.c

用ATmega8 做的MP3播放器

/*
 * Copyright (c) 2003-2004 K. John '2B|!2B' Crispin
 * Copyright (c) 2005      Stephan Dobretsberger
 *
 * 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, MA02111-1307USA
 *
 * Feedback, Bugs, ... mail [e-mail]
 *
 */

// avr includes
#include <avr/io.h>
#include <avr/signal.h>
#include <avr/interrupt.h>

// my lib header
#include "types.h"
#include "config.h"
#include "spi.h"
#include "delay.h"
#include "vs1001.h"
#include "mmc.h"
#include "fat.h"

#define PLAY_LED_ON   cbi(LED_PORT, LED_PLAY_PIN)
#define PLAY_LED_OFF  sbi(LED_PORT, LED_PLAY_PIN)

// our beeps
#define BEEP(x) { VS1001_volume(0x30, 0x30);                    \
                  beep(0x30, 70, x);                            \
                  VS1001_volume(player_volume, player_volume);  \
                }

// player states
#define IDLE                0
#define PLAYING_MMC         2
#define PLAYING_MMC_INIT    6

// Play modes
#define PS_SEQUENCE      0x01 // plays files in the order found. then the folders
#define PS_PLAYLIST      0x02 // the player found a playlist file on the mmc

// if the playlist file was not found the ps.pl_index is set to this
#define PLAYLIST_ERROR   0xff
#define PLAYLIST_NONE    0xfe

// what is the player doing atm ? and how is it doing it ?
typedef struct _P_STATE
{ // the current state
  u08 state;
  // what play mode are we using ?
  u08 mode;
  // what song are we on?
  u08 file_index;
}PLAYER_STATE;

// holds the last value read from the button port
static u08 last_button = 0x00;
// the current volume of the player
static u08 player_volume = 0x00;
// the number of beeps to generate
static u08 num_beeps = 0;
// the last byte that we received
//static u08 u_static = 0x00;
// what are we doing atm ?
static PLAYER_STATE ps;
// our mp3 file ptr
static FILE fp;


#ifdef PLAYLIST_SUPPORT
bool playlist_open(FILE *stream)
{ // make sure the file is closed
  fclose(stream);
  // try to open the playlist file
  return fopen("playlist.mu3", "r", stream);
};

// the index of the current playlist
u08 playlist_get_entry(FILE *stream)
{ // todo
};
#endif




// BEEP
void beep(u08 freq, u16 length, u08 intervals)
{ VS1001_SW_reset();
  VS1001_send_zeros(32);
  do
  { VS1001_sine(0x01, freq);
    delay_ms(length);
    VS1001_sine(0x00, 0x00);
    delay_ms(length);
  }while(--intervals);

};

// this function sets up the interrupt and ports used by the buttons
void setup_buttons(void)
{ // set ports for input
  cbi(BUTTON_DDR, BTN_VOL_UP);
  cbi(BUTTON_DDR, BTN_VOL_DOWN);
  cbi(BUTTON_DDR, BTN_SONG_UP);
  cbi(BUTTON_DDR, BTN_SONG_DOWN);
  cbi(BUTTON_DDR, BTN_PLAY);

  // enable pull-up (you don't need resistors on your PCB!)
  sbi(BUTTON_PORT, BTN_VOL_UP);
  sbi(BUTTON_PORT, BTN_VOL_DOWN);
  sbi(BUTTON_PORT, BTN_SONG_UP);
  sbi(BUTTON_PORT, BTN_SONG_DOWN);
  sbi(BUTTON_PORT, BTN_PLAY);

  // setup the led
  sbi(LED_DDR, LED_PLAY_PIN);
  PLAY_LED_ON;
};


// play the next file
void play_next(void)
{ ps.state = PLAYING_MMC_INIT;
  fclose(&fp);
  num_beeps = 1;
};

// go back a file
void play_prev(void)
{ ps.file_index--;
  if(ps.file_index > 0) ps.file_index--;
  // start player init process
  ps.state = PLAYING_MMC_INIT;
  fclose(&fp);
  num_beeps = 2;
};

// turn up volume
void vol_up(void)
{ // check if we can go any louder
  if(player_volume > 1) player_volume -= 2;
  // set new volume
  VS1001_volume(player_volume, player_volume);
};

// turn down volume
void vol_down(void)
{ // check if we can go any quiter
  if(player_volume < 180) player_volume += 2;
  // set new volume
  VS1001_volume(player_volume, player_volume);
};

// this function processes the button messages
void process_buttons(void)
{ // find out which buttons were pressed
  u08 tmp = inp(BUTTON_PIN);
  // invert as 0 -> button pressed
  tmp = ~tmp;
  // make sure the button was not pressed before
  u08 cleaned_val = tmp ^ last_button;
  cleaned_val = cleaned_val & tmp;
  // store current val as last val
  last_button = tmp;

  // button 1 was pressed -> song back
  if(cleaned_val&(1<<BTN_SONG_DOWN)) play_prev();
  // button 2 was pressed -> song next
  if(cleaned_val&(1<<BTN_SONG_UP))   play_next();
  // button 3 was pressed -> vol -
  if(cleaned_val&(1<<BTN_VOL_DOWN))  vol_down();
  // button 4 was pressed -> vol +
  if(cleaned_val&(1<<BTN_VOL_UP))    vol_up();
  // button 5 was pressed -> play/stop
  if(cleaned_val&(1<<BTN_PLAY))
  { if((ps.state == PLAYING_MMC_INIT) || (ps.state == PLAYING_MMC))
    { // stop the player
      ps.state = IDLE;
      if (ps.file_index>0)
        ps.file_index--;
      PLAY_LED_OFF;
      BEEP(3);
    }
    else
    { // go to start of file
      ps.state = PLAYING_MMC_INIT;
      num_beeps = 1;
    }
  }
}


int main (void)
{ // setup the player
  ps.state = IDLE;
  ps.mode = PS_SEQUENCE;
  ps.file_index = 0;

  // make sure the ptr for the mp3 file is setup correctly
  fclose(&fp);
  setup_buttons();

  // give mmc time
  delay_ms(1000);
  // set the MMC pins
  MMC_hw_init();
  spi_init();

  // init VS1001
  VS1001_init();
  VS1001_volume(player_volume, player_volume);

  // setup mmc
  MMC_init();

  // setup fat layer
  FAT_startup();
  BEEP(3);

  // show end of initialization
  PLAY_LED_OFF;

  num_beeps = 0;
  while(1)
  { // has the user pressed a button ?
    process_buttons();
    // what state are we in ?
    switch(ps.state)
    { // restart
      case PLAYING_MMC_INIT:
        // reset. decoder
        VS1001_SW_reset();
        // close last file
        fclose(&fp);
        // generate beep
        BEEP(num_beeps);
        // player led on
        PLAY_LED_ON;
        // find the next song
        if(fopenc(ps.file_index,'r', "*       MP3", &fp))
        { ps.state = PLAYING_MMC;
          ps.file_index++;
        }
        else
        { ps.file_index = 0;
          BEEP(6);
          break;
        }
      // playing
      case PLAYING_MMC:
        if(!fplay_sector(&fp))
        { fclose(&fp);
          ps.state = PLAYING_MMC_INIT;
          num_beeps = 1;
          PLAY_LED_OFF;
        }
        break;
    }
  }
  return 0;
}