Using GrOsmoSDR as signal source

András Retzler edited this page Feb 25, 2018 · 22 revisions

GrOsmoSDR is a GNU Radio block, which allows you to use variety of SDR hardware with OpenWebRX, including:

  • FunCube Dongle
  • bladeRF
  • ​HackRF
  • USRP
  • ​Fairwaves UmTRX
  • MSi2500 based DVB-T dongles
  • ​SDRplay RSP
  • ​AirSpy

Step #1: You will need to install GNU Radio and GrOsmoSDR:

sudo apt-get install gnuradio gr-osmosdr

Make sure you have at least GNU Radio version

:green_book: Since writing this article, a tool called has been released, which claims to do the same as steps #2-#6 below:

Step #2: Download osmocom_source.grc to the OpenWebRX directory.

cd openwebrx

Step #3: Execute the following:

mkfifo /tmp/osmocom_fifo

Step #4: Open osmocom_source.grc in GNU Radio Companion.

You can run GNU Radio Companion by:


...then select File > Open and look for the osmocom_source.grc.

Double-click the osmocom Source block, and configure the receiver.

Maybe Device Arguments is the most important field, which allows you to select the receiver. The format is like this:

<receiver type>=<receiver id or path>
  • If you want to use RTL-SDR #0 (the first RTL-SDR connected), you should enter: rtl=0
  • If you want to use HackRF #0 (the first HackRF connected), you should enter: hackrf=0
  • If you have an RFSPACE SDR-IQ on port /dev/ttyUSB0, then you should enter:

There are many other options detailed on the Documentation tab.


Step #5: Apply the same configuration to You will have to set at least the following settings:

  • center_freq
  • samp_rate

You will also have to uncomment the two relevant lines (and comment out the ones for RTL-SDR):

# >> gr-osmosdr signal source using GNU Radio (...)
#start_rtl_command="cat /tmp/osmocom_fifo"

Uncomment like this:

start_rtl_command="cat /tmp/osmocom_fifo"

Step #6: Execute the flowgraph in GNU Radio Companion (F6 or Run > Execute). This will supply the I/Q data for OpenWebRX.

Note: next time you can just run python from the command-line.

Step #7: While the flowgraph in GNU Radio Companion is running (in the background), start OpenWebRX:

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