Portable MP3 Player Based on AVR Butterfly

The purpose of developing this simple and cheap project is to use an AVR butterfly to create a portable MP3 player which is an open design in both hardware and software.

The AVR butterfly is an evaluation tool that is equipped with preloaded firmware where music playback, voltage readings, light measurement, and temperature sensing is supported. By using just a serial cable, the AVR butterfly can be reprogrammed from AVR Studio which allows the tool to be used as a development kit for the onboard ATmega169PV. Other handy peripheral like LCD indicator is also available aside from the ATmega169V microcontroller.

The MP3 decoding part has to be handled on other PCB since control and indication is ready. A VS1001K chips is used for MP3 decoding since it has on-board DAC with sufficient power for driving headphones. Instead of butterfly original LCD, a Nokia 3310 LCD screen can also be driven. The directories on SD card can be browsed due to the player firmware. It can also be controlled remotely through serial interface and the usage of battery can be indicated. The firmware can easily be adapted to work with other microcontrollers.

Rest of the project