Nice AVR based MP3 player… –
The MP3stick is a simple and small portable MP3 player. A microcontroller Atmel AVR ATmega128 is the heart of the circuit. MP3 decoding is done by an VLSI VS1011b decoder IC. A MMC/SD card works as memory medium for MP3 files, playlist files and skin files. The player is designed to draw his power from a LiIo/LiPo battery with 3.6V. a charger cicuit, based on MAX1811, is included. All information will be shown on a Nokia color LCD with 128×128 pixel and 256 colors. The player will work in text-only mode and if a skin file is available, also with nice graphic skins. A docking port allows outside connectivity for serial control signals, audio signals and charger voltage input.
ÛThe MP3 stick (DIY/Homemade MP3 player) – Link.