Gqrx with Funcube Dongle Pro+ support

You may have heard rumors about people using Gqrx with the Funcube Dongle Pro+. Well, it is true: There is now official support for the Funcube Dongle Pro+in Gqrx without the need for any ugly hacks.

Funcube Dongle Pro+ support is now available thanks to:

  • The gr-fcdproplus driver library by Volker Schroer.
  • Work by Alexey Bazhin on adding support to gr-osmosdr and gqrx.

I didn’t even have to do anything, beside some trivial integration and testing.

The gr-fcdproplus driver library is an out-of-tree GNU Radio module. This means that it must be compiled and installed after GNU Radio. Once installed, gr-osmosdr must be recompiled with FCD Pro+ support enabled. This will happen automatically (look in the summary at the end of cmake).

Note that gr-fcdproplus works only on Linux at the moment. I am going to update it to work on Mac OS X as well so that we can use gqrx 2.2 will have all supported devices on both Linux and Mac, but it will take a week or two before I get there.

I am not going to provide any step-by-step instructions for the above. Don’t worry if have no clue about what the above means. Gqrx 2.2 is just a few days away and we will provide binary packages¬† with Funcube Dongle Pro+ support enabled.

Until then, enjoy this video recording of Gqrx receiving a busy 40 meter band using the Funcube Dongle Pro+

Watch the video on Youtube.

Note that there appears to be a bug in the kernel USB driver that makes it misinterpret the bandwidth required by the FCD Pro+, reporting “insufficient bandwidth”. In such cases the FCD Pro+ will not work at all. The bug has been reported but it may take a while until fixed; however, there are a few potential workarounds you can try:

  • If you have a USB 1.1 port or hub try to use that (the FCD is a full-speed device).
  • If it fails in a USB 2 port. try a USB 3 port, if you have one.
  • If it fails in a USB 3 port, try a USB 2 port.

Eventually, we may even find a software workaround. Alexey had such patch for the GNU Radio 3.6 version but that is no longer applicable since the HID code has been updated to work with libusb again. So for now we only have the use-a-different-usb-port workaround that may or may not work.

Author: Alexandru Csete

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