This is a great hack, very clever. You mention on the GitHub page that you use a comparator to convert the signal for the ATMega168. I know that the ATmega328 has an embedded comparator so I'm wondering how easy you think it would be to create a library for Arduino projects?

I currently have a few projects which are bound to servers so I can control them with web apps and this seems like a great way to liberate them from the network. Low-level analog signal processing is about where my knowledge comes to a screeching halt (hence using Arduinos in the first place) but I'd love to play around with any AVR code to try and implement this for high-level language hardware people.

This is great! Very interesting idea, if I had more time I would incorporate it into my semester project. My solution using putty now looks so cheap.

Thanks for the tip! I'll try and implement this once I get the parts in for my new board.

Possibly. It was an embedded systems class, and I have a background dealing more with webdev and audio systems, so I figured I could combine all three into something novel. It actually worked out really well for the purpose, which was supposed to be a power-saving application. This way required only the addition of a comparator chip between the ATMega168 and the headphone line, which made it a super low power (and computationally light) way to communicate.

I personally love the portability that web api provides and the fact that I can run it without overhead right now.

Correct. The next step on this project will be to try and get two way communication working. I ran out of time before the class ended to get that established. If I remember correctly I ran into some issues with the mobile safari and the microphone input via javascript. I believe PhoneGap provides an API for this though.

I'm in the process of building a more general purpose dev board using the same processor I used for the class, so once I've got that up and running I'll try and post more "How to" related stuff on the github.