I'm trying to use a cheap mp3 player to play song using Arduino, I couldn't find the datasheet of the main chip but I made some progress identifying some pins.
Pin 1 16 Busy Play/Stop IO1 2 15 GND Prev/Vol- IO2 3 14 Next/Vol+ IO3 4 13 5 12 6 11 SPK - 7 10 SPK Right 8 9 SPK Left
This looks very similar to the picaxe by8001 and the WT5001
I will need some ideas to find the datasheet or at least find RX/TX/ADC KEY pins.
More pics here
Note: Why not use mp3 module for arduino? I try the WTV020 with no luck, I could buy a dfplayer or the WT5001, but this mp3 player cost 1/5 of those modules.