Sunday, January 13, 2019

Exploring Sub-GHz Radio With RTL-SDR and GQRX

Today I took a look at some hardware for working with sub-GHz radio transmissions, especially FM. All of which came in a previous HackerBoxes box. My favorite item was definitely the RTL-SDR dongle! I could play around with this thing for hours surfing the radio waves and listening to weird broadcasts. There's even a Python library named pyrtlsdr for working with these devices so you can scan/record radio transmissions programmatically: https://github.com/roger-/pyrtlsdr

Next I'm going to solder together the FM transceivers included in the box and play around with writing Arduino firmware for them. Those things should work similar to the LoRa modules I've been using but they trade in the long range for increased bandwidth. Should be good for streaming data locally and still have much better range than most home WiFi or Bluetooth.

Here's a video overview of the hardware included in HackerBox 0034 as well as a demo of the RTL-SDR dongle using GQRX to visually and audibly explore the radio waves.



The audio in my videos has also improved a bit since being sent this Purple Panda lapel microphone. If you do any audio recording with your laptop or phone this little mic is cheap and it definitely improves the quality over a builtin mic. [Not a sponsor, they did send this for free but it's also only $20. I really needed a mic.]