Great Scott Gadgets
Software Defined Radio with HackRF, Lesson 11
In order to clearly see my screen during the demonstrations, viewing the video in full screen mode may help. Even better: You can download this video in high resolution (720p). (torrent)
In this Lesson
- being a good neighbor on the spectrum
- QT vs. WX GUI in GNU Radio
- saving a waveform to file
- replaying a captured radio signal
- using multiple HackRF Ones
Capture a radio signal and save it to a file with hackrf_transfer ( Hint: use the -r option).
Convert the file from unsigned 8-bit integers to 32-bit floats. This can be done with:
sox foo.s8 foo.f32
cat foo.s8 | csdr convert_s8_f > foo.cfile
or with convert_s8_cfile.grc.
Analyze the file with GNU Radio Companion and/or inspectrum to verify that you captured your signal of interest.
Determine how many distinct sample values are present in your signal. (Hint: The number should be no more than 256.)
How many bits of dynamic range does your signal span. (Hint: take the base 2 logarithm of the number of distinct sample values.)
- inspectrum, software used to produce the spectrogram in this lesson. The latest bootable release of Pentoo Linux includes inspectrum.
- the lesson 11a flowgraph: lesson11a.grc
- the lesson 11b flowgraph: lesson11b.grc
- a flowgraph that converts complex signed integers to complex floats: convert_s8_cfile.grc
Software Defined Radio with HackRF is copyright 2014, 2015 by Michael Ossmann and is released under the CC BY license.