Ham Radio Traffic Logger Using A Bug In Baofeng Electronics
Baofeng radio is often one of the first purchases made by a new ham radio operator these days due to its decent features and low price. They are far from perfect, but with a little creative inspiration it is possible to make quirks work in your favor. Taking advantage of the strong pop-up of the headphone outputs each time you turn on the LCD backlight, [WhiskeyTangoHotel] built a radio traffic counter using ESP8266.
Whenever there is a transmission on one of the frequencies on which the radio is tuned, the backlight turns on. Connecting the audio output to an oscilloscope, [WhiskeyTangoHotel] measures a 5V jump when this happens. Using a pair of diodes in series to reduce the voltage to a safe level, the ESP8266 detects a voltage spike and updates a Google spreadsheet with the time stamp via IFTTT.
That gave [WhiskeyTangoHotel] empirical data on how much traffic passes through the local VHF repeater, but we would not blame them if the hack itself was the real motivator.
Of course, this would also be an ideal application for RTL-SDRwhich should allow you to do the above and much more, all in software. Add a little AI and you can even remove the call signs. RTL-SDR is also a good learning tool RF modulation.
UV5-R image via PE1RQM