Last update, I talked about choosing embedded Linux over a micro-controller to continue this project and how I would be playing with Buildroot to better understand that system. I've done that and WOW! (Almost) all the firmware functionality you've ever wanted has been pre-written for you to use for free... if you figure out how to configure the kernel. Getting a bare image of Buildroot is fairly straight forward, but I got lost in configuration hell trying to setup all the peripherals on the existing prototype.

This made me take a step back and ask why I was down this path. The whole reason I had decided on embedded Linux vs a micro-controller was adding audio to the project would require more than userspace GPIO manipulation. After investigating other commercial e-readers, almost none of them have a 3.5mm audio jack, but instead rely on connection to a Bluetooth device. This is the route I went, and by the time you're reading this, the project description will be updated with exactly how this is done.

This is the last update because the project does everything I want it to do at this point. It can read ebooks, play audiobooks, and sync with a remote server to download books. It is by no means polished, but it's the proof of concept I wanted to make when I began this idea.