stayPRS and FOXmtr
I have a Baofeng UV-5R handheld that no longer sees much use. I also have an idle Arduino microcontroller. I wanted to find a way to put them both to work, but I couldn’t decide whether to make a foxhunt transmitter or an APRS beacon.1 There are excellent articles online describing various ways to make one or the other. I decided to try to combine both applications in a single project. You can see short video demos of this project in APRS mode at <https://youtu.be/_zuubDFbyZM> and in foxhunt mode at <https://youtu.be/SvAG6S0d3hE>.
One of my goals was to avoid having to use an MP3 player with a pre-recorded audio foxhunt message to play into the Baofeng mic input. Before I retired from teaching at a STEM2 magnet school, I helped students use Arduinos in some of their hands-on school projects. One assignment required writing an Arduino sketch3 that could send Morse code messages to a piezo buzzer. As a result, I already had the code for an MCW (Modulated Continuous Wave) foxhunt beacon. Just feed the Arduino audio output into the Baofeng mic input instead of into a piezo buzzer! I decided to give that a try.
The Arduino coding for an APRS beacon, on the other hand, is beyond my skill level. Luckily, a web search turned up Arduino code written by a young Indonesian ham who is now an engineer — Han Gesang, YC1SDL. He has generously made his Arduino sketches available to all under the GNU General Public License. However, his code was written to include a GPS receiver. I just
