Years ago I built an Arduino-TNC [1] that was based off of a design by Mobilinkd [2]. It was a KISS TNC that you could connect to your computer or your cell phone and use it to communicate over the air waves with your ham radio. The original one that I made was slightly different than the design, because I didn't have the proper transistor at the time, so I just used a relay and slowed down the baud rate instead. After some initial testing, it turned out not to work super well, being very slow and occaisionally locking up, and I ended up putting it into a drawer where is later got bashed around and broke.

Recently, I decided to rebuild the Arduino-TNC but to stick with the original design. As a Christmas gift, my parents got me a box of a lot of electronic components this past winter, and in there were the proper transistors! (Thanks Dad and Mom!) I've been putting quite a few of the components to work in small projects, and this was no exception. I now had all the right capacitors, resistors and transistors for the project. I wont rehash what I already said before about how to build one, especially since I just followed the original design, which is also linked at the end of this article. I will, however, share some photos of the build:

It was a lot of fun to get back into hands on electronics work, dusting off the soldering iron, firing up the 3D printer, and building something. Even better is when it worked during testing! I wired it up into my truck for use with the HTX-212, and I'll road test it for a while before I put it to use at the house with my old trusty TS-700A for Winlink and APRS. As you can see in the pics, I can reconfigure the pins as needed for the cable inside the unit, allowing me to change what I am using it for. The yellow case I printed [3] was not designed by me, but it pops open and shut without screws, and stays pretty tight when closed.

Linux - keep it simple.

[1] https://alaskalinuxuser3.ddns.net/modded-arduino-tnc-finally-sends-the-first-email.html [2] https://www.mobilinkd.com/2014/09/11/arduino-kiss-tnc/ [3] https://www.thingiverse.com/thing:6429645