I'm going to give a quick rundown of what my ideas were before I got to this point.

First off my initial idea was to gut the walkman and install a Raspberry Pi with a nice audio DAC. I had bought some parts and it wasn't exactly coming together very smoothly. I was quickly running out of room and my button set up was juvenile to say the least.

(Yes that is a popsicle stick)

Hypothetically from there I would have used a teensy to emulate a keyboard, and I would have written a small media player on the RPi to display on this tiny composite screen.

Noticing all of the flaws I decided it would be best to go with an android phone, and I bought a few on the cheap off of ebay for around $15 each. To interface with the android phones I looked around and found the IOIO board, which is one of the coolest boards in my eyes.

For the senior project class, research was a required part of the curriculum and I annotated the IOIO documentation on Analog I/O and Digital I/O (Yati). The IOIO board would have allowed me to add analog input from the volume pot and I would have been able to add a status LED to shine through where there was one originally on the device. I was also planning to write an android program that issued media commands to the device through a IOIO connected app. These were features I'm willing to put off (for now).

To get things moving more quickly I switched to the Bluefruit EZ-key, which added some more flexibility and a smaller form factor (albeit some weird programming software).