• Directories must be consecutively numbered ##
  • There must be always a 01 directory
  • No gaps in the numbering
  • No sub directorys
  • No files in the SD card root directory
  • No other files than wav or mp3 in the directorys
• The files must be consecutively numbered ###${NAME}
  • Also across directory boundaries
  • No gaps in the numbering
• On a Mac:
  • remove all hidden mac files
    • see https://www.techwalla.com/articles/how-to-show-and-hide-hidden-files-on-mac-os-x

Example:

/-+- `01`
  |   + `001_Happy_Dance.mp3`
  |   + `002-O_Sole_Mio.mp3`
  |
  +- `02`
  |   + `003Humpty_Dumpty.mp3`
  |   + `004-Incy_Wincy_Spider.mp3`
  |   + `005-Grand_Duke.mp3`
  | 
  +- `03`
      + `006-Fernando.mp3`
      + `007-Mamma_Mia.mp3`

• https://github.com/MajicDesigns/MD_YX5300
• https://github.com/salvadorrueda/SerialMP3Player