Yesterday, I had the privilege of giving a talk about a project I’d been working on to the Wild West Hackinfest in Deadwood, SD. Over the last year or two I’d been wanting to build a clean radio communication system using SDR and gnuradio. There were a number of not-so-obvious things I’d learned over the years, and I thought releasing some code that implemented such a system could help out folks that may have been struggling with some of the same things that I did.
The project I settled on was an RF exfiltration system, with a host laptop sending commands to a headless Raspberry Pi 3 B+. The twist, however, was that each time the host requested data, it also told the xfil box how to send the data: what frequency, modulation scheme, preamble, etc. The goal was to be able to communicate in a manner that was as flexible as possible, even capable of changing the RF parameters with each transmission.
The code is still at “proof-of-concept maturity” but it should help you see how to get digital payloads from external Python code into a flowgraph (on transmit) and vice versa (on receive). You can see it all here:
http://github.com/paulgclark/exfil
I’m incredibly grateful to John Strand and all the folks who made the conference happen. It’s an awesome event with great people both running and attending. If you haven’t been, you should definitely go in 2019.
PS There was a camera running, so I’ll provide an update post when the video is posted.