On the 3-rail forum, there is a topic running, about using MP3’s, in conjunction with (model)railroads …
I found some cheap MP3 modules on Ebay, a complete MP3-player, for less then 2 Euro ! It comes with an internal battery, audio jack output, and microSD slot (max. 8 GB) I already did dismantle a lot of these units 🙂 It’s simple:
- Unscrew the 2 screws
- Slide out the internal electronics, to the backside of the MP3 player
- Take of the sticket that sits above the buttons
- Solder a wire to the middle of those round dots, and one to the external of those round dots. You can use a relais or Max313 or something similar, to “control” the buttons. (a total of 5 buttons), so you can control the “previous song”, “next song”, play/pause, volume up and volume down …
Take a look at my home automation electronics, there is already a board named “MP3 light controller”, I used that board to control those little MP3 players. It should give you a good indication on how to wire-up those things 🙂