onesky:
something odd: if you want to keep the files order, firse must create the mp3 playlist on hard disk (0001.mp3, 0002.mp3, ecc) and when ready copy to the micro-SD card. If you rename on microsd card it will messy the order.
With all of these modules, the name doesn't matter. It is the actual order that they are found in the directory entry table. So, if you were to name your files 001.mp3, 004.mp3... and then copy 004.mp3 first, then 001.mp3, it would make 004.mp3 track number one and 001.mp3 track number 2.
So you can name the files however you want. But you must be careful what order they are in the directory entry.
To make things easy, just copy all your files over and use this program:
to sort where the files are put in the directory entry. Pretty much all of these modules have this same issue because they use a very simple FAT access routine.