The current prototype makes use of either a Nokia 3310 LCD screen or the original alphanumeric LCD. This was used initially because I dropped my original Butterfly and broke the screen, but it also frees up a lot of IO on the Butterfly which I hope to use in the future for implementing a ATA/ CF interface.
The cost of this project is around $50-$100 depending on what type of screen you use and other components. This project will never compete with any mass produced products but is aimed at anyone wanting to learn about MP3 Players, Electronics, PCB design or Firmware design. The firmware can easily be adapted to work with other Atmel AVR micro-controllers and your own custom designs.
A basic PCB has been designed and manufactured; and software has been written to test the hardware capabilities of the device. The current firmware is fully functional to the point of selecting songs on the MMC and playing them, pausing or skipping to the next song. In future releases it is hoped to enhance these features.
The current focus of development is on a revised hardware design with a newer VS1011 or VS1053 decoder chip and an SD card socket. The latest version for the hardware is Revision F. This adds an SD connector so the project can use both SD and MMC media. I have recently developed better documentation to show construction from start to end. You can find the new documentation here
The development has been branched into an ATA development branch and MAIN development branches. The main branch is the original design with an SD/MMC card and alpha numerical or graphical LCD. In the CVS the last release version is tagged STABLE.
The last firmware release (0.6) was 4 June 2007. This is added a number of new features including:
Hardware was designed and partially debugged for work to begin on a HDD version using 2.5" drives with USB 2.0 connection but active development on this branch has stalled due to the low cost of high capacity SD cards. The work done so far is available from CVS under the ATA branch. The case designs for the basic SD/MMC versions are complete.
The Rev D PCB is complete and adds support for li-ION polymer batteries and USB charging. The Rev E PCB uses less power due to using a different voltage regulator. The MMC card socket is no longer stocked by Farnell. The Rev F PCB uses an SD/MMC card socket stocked by Farnell.
The planned developments for this device (in rough order of priority) are:
Here are some web pages which I have found useful during my time working with AVR microcontrollers and MP3 Players. If you would like to contribute or have any questions please visit the project page and forums here.