So here is a small project that plays *.WAV files from a FAT16 formated SD card.Audio output is done using PWM and a RC filter to smooth it out.Its built very modular so you can take the hardware drivers out very easily as they are grouped in folders.
Supported wav formats:
PCM 8bit mono
PCM 8bit stereo
PCM 16bit mono
PCM 16bit stereo
Supported sample rates:
1-192Khz (nonstandard rates are ok)
Note: The normal SD cards are too slow to play very high bitrate wav files!