Software Defined Radio with HackRF, Lesson 1 - Great Scott Gadgets

Great Scott Gadgets

Software Defined Radio with HackRF, Lesson 1


In order to clearly see my screen during the demonstration, viewing the video in full screen mode may help. Even better: You can download this video in high resolution (720p). (torrent)

In this Lesson

  • welcome to the video series
  • introduction to SDR
  • introduction to HackRF
  • course background
  • introduction to GNU Radio Companion
  • “hello world”, receiving FM radio


  1. Try Pentoo Linux: Follow the instructions at Getting Started with HackRF and GNU Radio.

  2. FM radio flowgraph: Create a flowgraph in GNU Radio Companion like the one in the video or the screenshot below. Test the flowgraph by listening to a strong FM radio signal.

FM radio RX flowgraph screenshot

  1. Add a channel slider: Add a slider to your FM radio flowgraph and use it to change channels while your flowgraph is running.

  2. Add a second channel: Update your FM radio flowgraph so that it allows you to listen to two radio stations at the same time. Hint: Use an Add block to combine two audio signals.



  • 25 August 2014: The original video encoding had some problems. I produced a new encoding so that iPad and Safari users can hear the sound. I also improved the audio/video synchronization and filtered the audio a bit.
  • 25 August 2014: I pointed out the “gears” icon in GNU Radio Companion. In future versions, this changes to a triangular “play” icon.
  • 5 October 2015: I used the WX GUI option in GNU Radio Companion. The default has since changed from WX GUI to QT GUI in the Options block. If you are using a newer version of GNU Radio, you’ll need to change it back to WX GUI to follow along with my flowgraph.

Software Defined Radio with HackRF is copyright 2014, 2015 by Michael Ossmann and is released under the CC BY license.