You could use ESP32 BT keyboard in your projects. Simply connect original buttons like "play", "ff" etc to ESP32. Then use standard bt keyboard library. It works well. You can also use IR receiver and original remote commander (in case you have one). My approach is to use a mp3 player module from aliexpress. I have to reconnect all buttons, potentiometers, move lcd from module to the front of deck, maybe use bigger one. The biggest goal is to place USB and SD slot in cassette compartment. This chaep mp3 player Right now, the hardest part is detaching the lcd from the original pcb and maybe replacing it with a bigger one.
