Building on the file listing code from the previous post in the next class we built a basic multi threaded music player using an enhanced version of the Vs1053B driver based on the softelectrotech.and bluecone code.

The code uses five interrupt ports (I used 5 buttons on the 4 analog ports on the Seeedstudio V2 Base shield and D5 to make it easier to fit the Mp3 shield)

As the Vs1053 driver is now running asynchronously it fires an event when the current track has finished playing

   public class Program
   {
      static string[] MusicFiles;
      static Vs1053B player = new Vs1053B(Pins.GPIO_PIN_D2, Pins.GPIO_PIN_D6, Pins.GPIO_PIN_D7, Pins.GPIO_PIN_D8);
      static byte volume = 200;
      static int trackNumber = 1;
      static public string TrackFilename { get { return MusicFiles[trackNumber - 1]; } }

      public static void Main()
      {
         MusicFiles = Directory.GetFiles(@"\SD");

         foreach( string file in MusicFiles)
         {
            Debug.Print(file);
         }

         InterruptPort playPause = new InterruptPort(Pins.GPIO_PIN_D5, false, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeLow);
         playPause.OnInterrupt += playPause_OnInterrupt;

         InterruptPort volumeUp = new InterruptPort(Pins.GPIO_PIN_A0, false, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeLow);
         volumeUp.OnInterrupt += volumeUp_OnInterrupt;

         InterruptPort volumeDown = new InterruptPort(Pins.GPIO_PIN_A1, false, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeLow);
         volumeDown.OnInterrupt += volumeDown_OnInterrupt;

         InterruptPort previousTrack = new InterruptPort(Pins.GPIO_PIN_A2, false, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeLow);
         previousTrack.OnInterrupt += previousTrack_OnInterrupt;

         InterruptPort nextTrack = new InterruptPort(Pins.GPIO_PIN_A3, false, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeLow);
         nextTrack.OnInterrupt += nextTrack_OnInterrupt;

         player.SetVolume(volume);
         player.Filename = TrackFilename;
         player.onMusicFinished += player_onMusicFinished;

         player.Play();

         Thread.Sleep(Timeout.Infinite);
      }

      static void player_onMusicFinished()
      {
         trackNumber += 1;

         if (trackNumber > MusicFiles.Length)
         {
            trackNumber = 1;
         }
         Debug.Print("player_onMusicFinished " + trackNumber + " of " + MusicFiles.Length);

         player.Filename = TrackFilename;
      }

      static void previousTrack_OnInterrupt(uint data1, uint data2, DateTime time)
      {
         trackNumber -= 1;

         if (trackNumber  MusicFiles.Length)
         {
            trackNumber = 1;
         }
         Debug.Print("nextTrack_OnInterrupt " + trackNumber + " of " + MusicFiles.Length);

         player.CancelPlayback();
         player.Filename = TrackFilename;
      }

      static void playPause_OnInterrupt(uint data1, uint data2, DateTime time)
      {
         Debug.Print("playPause_OnInterrupt ");
         if (player.IsPaused())
         {
            player.Resume();
         }
         else
         {
            player.Pause();
         }
      }

      static void volumeDown_OnInterrupt(uint data1, uint data2, DateTime time)
      {
         Debug.Print("volumeDown_OnInterrupt " + volume);
         if (volume > 0)
         {
            volume -= 1;
         }
         player.SetVolume(volume);
      }

      static void volumeUp_OnInterrupt(uint data1, uint data2, DateTime time)
      {
         Debug.Print("volumeUp_OnInterrupt " + volume);
         if (volume < 255)
         {
            volume += 1;
         }
         player.SetVolume(volume);
      }
   }

Next steps are to ignore contact bounce on the buttons and play MP3 files in a more consistent order
musicplayerv2

Netduino Mp3 player with 5 button UI