What is it?
The Arduino MP3 shield is an add on board for developing Arduino based systems that incorporate MP3 decoding, SD cards and Joysticks. It is initially based on the work done as part of the ButterflyMP3 Project.
The board will take standard MP3 files from a FAT16 formated SD card and play them via a standard 3.5mm headphone jack. A 5 way joystick is included to allow user interaction with the baoard. The final behaviour of the system is completely controlled by the Arduino board with the shield simply making the peripherals available over the SPI bus (SD Card and MP3 Decoder) and digital I/O (Joystick).
Basic examples and libraries are provided for use with the shield.
Why did you design it?
I've enjoyed developing the ButterflyMP3 over the last 5 years and as the Arduino has become popular I noticed that the Butterfly MP3 project is basically a shield for the AVR butterfly.
With a few simple changes to meet the needs of the arduino the Arduino MP3 was born.