AVR butterfly Mp3: a diy mp3 player

The design is based around the AVR Butterfly from Atmel. The use of this module greatly simplifies the hardware design and constrution and packs plenty of punch for $19.99 USD. The remaining hardware can be easily placed on a single sided PCB ($10-$20). The MP3 decoding is handled by a VS1001K decoder chip from VLSI Solution Oy ($20). This chip also has an onboard DAC with enough power to drive headphones, simplifying the board design even further.

AVR butterfly Mp3: a diy mp3 player: [Link]

you should also check the DIY Mp3 player article i wrote some time ago.