Gqrx with the Red Pitaya

Today it was brought to my attention that gqrx works well with the Red Pitaya board running the SDR transceiver code by Pavel Demin. Indeed, looking through the gr-osmosdr commit logs, I could see support was added in December 2015, just around the same time I was packaging gr-osmosdr.

To make it work, start with the official Red Pitaya image. The SDR transceiver code can be installed through the Red Pitaya application marketplace. There are two versions and we need the one that is compatible with GNU Radio.

Once installed, we can launch the SDR transceiver application through the web interface, though this is not much fun since it will only run as long as you have the web page open. Instead, we can launch the servers from the command line:

cd /opt/redpitaya/www/apps/sdr_transceiver
cat sdr_transceiver.bit > /dev/xdevcfg

The script will load and configure the FPGA, then launch both transceivers 1 and 2 using input/output 1 and 2 and network port 1001 and 1002 respectively. You can edit te script if you only want to start one transceiver.

There is also a script for stopping the transceivers.

Setting up a script for starting the transceiver(s) automatically at boot is left as an exercise, however, you can find inspiration in Pavel’s  code repository.

On gqrx side you will need to use the latest gr-osmosdr. I have already updated the myriadrf/gnuradio PPA and gqrx packages will follow shortly. You can still use the current gqrx 2.5 and 2.5.1 but you will have to enter the sample rate yourself.

Supported rates are: 20000, 50000, 100000, 250000, 500000 and 1250000.

In the device string enter the correct IP and port number. After that it should just work :-)

Gqrx running with the Red Pitaya

Gqrx running with the Red Pitaya

Gqrx running with the Red Pitaya

Author: Alexandru Csete

Embedded software engineer in the satcom industry during the day. Radio amateur and SDR hacker during the night.