I've done a test layout to play with that I'll be testing in the next few days. Below is the layout.
Several folks have asked about using Arduinio hardware with APRS TNC. I don't have a lot of motivation but figured I'd get the project started. If you have an arduinio and would like to help develop this using arduino hardware please post (no emails please). Here is the alpha schematic I'm working on using the display I started with in the original design.
I've gotten ton's of emails (100 or so) about the code for the APRS node I've been hacking away at. I normally use an Arduino type board for prototyping. However, the code is in C. I do sometimes use processing to quick test something but generally things destined for the embedded world are in C. Below are some projects I found related to what I am working on. Some use the CML chips some don't. In the low cost model I don't use it. I have been playing with a CML chip for digital type radios but they drive the cost up with what I am attempting to do which is build a device within the reach of just about any public safety department in volume. And please if you don't mind, post questions as comments rather than emailing me directly. That ensures that any Q&A can be seen by everyone.
http://garydion.com/projects/whereavr/ - This is a really nice setup, different application but very tidy setup.
http://sites.google.com/site/ki4mcw/Home/arduino-tnc - Hope to see more from this. Its what more of you are looking for with PDE files provided.
I have several radios that don't have CTCSS or the ability to page out fire tones. I figured I'd solve it with a programmable AVR. I started with a basic Arduino board and progressed to c code to control various circuits for the generation and detection of tones. I'll be posting some pics and information soon.
In 2004, we had a large flood in area and departments from other areas of the state came to the EOC to help. One of the big issues was getting radios programmed so we could talk to each other. Recently while playing with my Kenwood TK-380 I wanted to see how hard it was to capture and view the data. Using a simple processing script I dumped the data to disk and could see it was binary data.