song_task.c

开发工具:keil7 主要IC：at89c51sdnd1(atmel) 说明：mp3播放器详细设计方案

          {
            song_state = SONG_NEW;
            gl_key_press = FALSE;           /* no key usage */
          }
          else
          {
            song_state = SONG_STOP;
          }
        }
        else
        {
          song_state = SONG_PLL;
        }
      }
      else
      {
        song_state = SONG_ERROR;
      }
      break;
    }


    case SONG_PLL:
    {
      if (Pll_get_lock())                   /* pll locked? */
      {
        song_start();                       /* start playing song */
        disp_clock_start();                 /* start clock timer */
        print_state_play();                 /* display play icon */
        song_state = SONG_PLAY;
      }
      break;
    }


    case SONG_PLAY:                         /* one file openned */
    {
      if ((MP3STA1 & MSK_MPFREQ) == MSK_MPFREQ)
      {
//      RXD = 0;
        do
        {
          Mp3_load(Fgetc());                /* send data while requested */
          if (gl_mem_failure)
          { /* hardware failure */
            song_state = SONG_ERROR;        /* in case of read error */
            break;
          }
        }
        while ((MP3STA1 & MSK_MPFREQ) == MSK_MPFREQ);  /* frame request ? */
//      RXD = 1;

        if (Feof() == TRUE)                 /* end of file? */
        {
          song_stop();                      /* stop playing song */
          Fclose();
          if (file_seek_next(FILE_MP3, song_loop))   /* select next song */
          {
            song_state = SONG_NEW;
            gl_key_press = FALSE;           /* no key usage */
          }
          else
          {
            song_state = SONG_STOP;
          }
        }
      }


//      if ((MP3STA & (MSK_ERRLAY | MSK_ERRSYN)) != 0)
//      {
//        mp3_restart();
//        break;
//      }

      if (gl_key_press)                     /* a key is pressed? */
      {
        switch (gl_key)
        {
          case KEY_PAUSE:
            Aud_song_pause();               /* suspend sample request */
            disp_clock_stop();              /* suspend clock timer */
            print_state_pause();            /* display pause icon */
            song_state = SONG_PAUSE;
            break;

          case KEY_NEXT:
            song_stop();                    /* stop playing song */
            disp_clock_stop();              /* suspend clock timer */
            Fclose();
            file_seek_next(FILE_MP3, TRUE); /* select next song & loop */
            song_state = SONG_NEW;
            break;

          case KEY_PREV:
            song_stop();                    /* stop playing song */
            disp_clock_stop();              /* suspend clock timer */
            Fclose();
            file_seek_prev(FILE_MP3);       /* select previous song */
            song_state = SONG_NEW;
            break;

          case KEY_INC:
            song_snd_inc();                 /* increment selected control */
            print_sound_level();            /* display new level */
            break;

          case KEY_DEC:
            song_snd_dec();                 /* decrement selected control */
            print_sound_level();            /* display new level */
            break;

          case KEY_SOUND:
            song_snd_select();              /* select next sound control */
            print_sound();                  /* display selected sound icon */
            print_sound_level();            /* display new level */
            break;

          case KEY_REPEAT:
            song_loop = ~song_loop;         /* display repeat or not */
            print_repeat(song_loop);
            break;

          case KEY_STOP:
            song_stop();                    /* stop playing song */
            Fclose();
            song_state = SONG_STOP;
            break;

          case KEY_LOCK:
            print_kbd_lock();               /* print keyboard status */
            break;

          default:
            break;
        }
        gl_key_press = FALSE;               /* ack key usage */
      }
      break;
    }


    case SONG_PAUSE:                        /* one file openned */
    {
      if (gl_key_press)                     /* a key is pressed? */
      {
        switch (gl_key)
        {
          case KEY_PLAY:
            disp_clock_start();             /* restart clock timer */
            Aud_song_play();                /* restart sample request */
            print_state_play();             /* display play icon */
            song_state = SONG_PLAY;
            break;

          case KEY_NEXT:
            song_stop();                    /* stop playing song */
            Fclose();
            file_seek_next(FILE_MP3, TRUE); /* select next song */
            print_file_name();              /* display song name */
            song_state = SONG_IDLE;
            break;

          case KEY_PREV:
            song_stop();                    /* stop playing song */
            Fclose();
            file_seek_prev(FILE_MP3);       /* select previous song */
            print_file_name();              /* display song name */
            song_state = SONG_IDLE;
            break;

          case KEY_INC:
            song_snd_inc();                 /* increment selected control */
            print_sound_level();            /* display new level */
            break;

          case KEY_DEC:
            song_snd_dec();                 /* decrement selected control */
            print_sound_level();            /* display new level */
            break;

          case KEY_SOUND:
            song_snd_select();              /* select next sound control */
            print_sound();                  /* display selected sound icon */
            print_sound_level();            /* display new level */
            break;

          case KEY_REPEAT:
            song_loop = ~song_loop;         /* display repeat or not */
            print_repeat(song_loop);
            break;

          case KEY_STOP:
            song_stop();                    /* stop playing song */
            Fclose();
            song_state = SONG_STOP;
            break;

          case KEY_LOCK:
            print_kbd_lock();               /* print keyboard status */
            break;

          default:
            break;
        }
        gl_key_press = FALSE;               /* ack key usage */
      }
      break;
    }


    case SONG_NEW:
    {
      song_state = SONG_INIT;               /* new song */
      print_file_name();                    /* display file name */
      break;
    }


    case SONG_STOP:
    {
      disp_clock_reset();                   /* reset clock timer */
      print_file_name();                    /* display file name */
      song_state = SONG_IDLE;
      break;
    }


    case SONG_NO_SONG:
    {
      if (gl_key_press)                     /* a key is pressed? */
      {
        switch (gl_key)
        {
          case KEY_MEM:
            mem_select_next();              /* select next memory */
            song_state = SONG_START;
            break;

          case KEY_MODE:
            mode_set_init();                /* exit from song task */
            song_state = SONG_START;
            break;

          case KEY_LOCK:
            print_kbd_lock();               /* print keyboard status  */
            break;
        }
        gl_key_press = FALSE;               /* ack key usage */
      }
      else
      { /* check card presence */
        if (mem_check_card() == KO)
        {
          mem_select_next();
          song_state = SONG_START;          /* card has been unplugged */
        }
      }
      break;
    }


    case SONG_ERROR:
    {
      song_stop();                          /* stop playing song */
      Fclose();                             /* close opened file */
      disp_clock_reset();                   /* reset clock timer */
      print_state_error();                  /* display error icon */
      disp_name_stop();
      song_state = SONG_IDLE;
      break;
    }
  }
}