    - Next Track           - play the next track in a consecurtive list of ordered files
    - Pause / Resume       - pauses the playback or unpauses a paused playback
    - Light on / off       - turn the operations light fader on or off
-
-
-   Some features (as e.g. Remote Control, Buttons or operation LED etc.) can be turned off 
-   or on via #define switches in the code below.
-   
+   
+    
    Used Pins:
+   ---------------------------------------------------------------------------------------
      NAME             PIN  USAGE
    - CLK / PN532_SCK   13  SPI Clock shared with VS1053, SD card and NFC breakout board 
    - MISO / PN532_MISO 12  Input data from VS1053, SD card and NFC breakout board 

   - no directory found on the SD card that match the NFC Tag TrackDB record
   - no file(s) in the directory on the SD card

   
   4 buttons are included:
   - Previous Track       - play the previous track in a consecurtive list of ordered files
   - Next Track           - play the next track in a consecurtive list of ordered files

   4. if a file is missing in a consecutive order, you may get a glitch in the sound 
   5. As the Adafruit Music Maker Shield library does not support to jump to a specific 
      position within a file, the box can always only start from the beginning of a track.
   
   
   Warnings and errors
   ---------------------------------------------------------------------------------------
   On warnings or errors a warning or error light is lit up respectively. There are 3 
   different warning or error conditions:
   1) Missing information for playback warning
   2) Low Battery warning
   2) Missing hardware error
   
   Errors shown via the error light (also cause the system to halt):
   - Music Maker Shield not found
   - Music Maker shield not on an interrupt enabled pin
   - SD card not found
   - NFC Reader not found

   Warnings shown via a light (Arduino can stay turned on):
   - Low battery warning (surely the arduino will turn off but until then it will operate)
   - no directory found for the NFC Tag (aka TrackDB is missing an entry for the Tag)
   - no directory found on the SD card that match the NFC Tag TrackDB record
   - no files in the provided directory
