Cart is empty Lesson 11 Overview
- Being a good neighbor on the spectrum
- QT vs. WX GUI in GNU Radio
- Saving a waveform to file
- Inspectrum
- Transmitting
- Replaying a captured radio signal
- Using multiple HackRF Ones
Homework
- 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
or:
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.)
Resources
- 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
Disclaimer
Software Defined Radio with HackRF is copyright 2014, 2015 by Michael Ossmann from greatscottgadgets.com and is released under the CC BY license.
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