Gnuradio streaming between two computers?

Question

Is there a simple way to implement communication between two computers running GNUradio using the standard blocks set?

What I am have now is this:

On a Linux computer, GNUradio is running and receiving input from a Radio peripheral. On that computer I can see the received waveform on a WX scope. I can also use sliders and input boxes to change things like the receiver frequency.

What I'd like to do is this:

On a Windows computer, I have the WX scope and sliders. When I move the a slider or change an input box, that data gets sent to the Linux, which is still running the radio receiver on Gnuradio. The received signal goes through a stream back to the windows, and gets displayed on the WX scope on Windows.

Someone elsewhere suggested using the ZMQ blocks, however, when I tried setting up a PUSH/PULL to transmit a sine wave from the Linux to the Windows, nothing went through. The guy who recommended that approach tried the same and also could not get it working, so I think that block might be broken?

So is there any alternative blocks that can do what I'm trying to do? Preferably something well documented, and available on GNUradio-companion.

Answer 1

Depending on the data rate from the receiver, it's possible to encounter performance issues attempting to send raw waveform data using e.g. the UDP blocks, where the sender may print an error similar to the following:

gr::log :WARN: udp_source0 - Too much data; dropping packet.

Because the scope widgets usually only display a portion of the input data, a more ideal way of remotely visualizing the waveform might be to only send the rendered scope widget (e.g. using a remote desktop such as VNC or X2Go). Although this solution reaches beyond your original problem, it is probably easier to use in the long run for cases involving two-way GUI interaction.

Answer 2

For the scope widget data, the UDP sink and source blocks seem to be native to GNU Radio, and are either sufficiently documented solution or simple enough for this problem, again taking firewall configuration into consideration as @Zephyr mentioned.

From GRC, specify in the UDP blocks:

1. the hostname or IP address of the display computer, and

2. a choose port number that isn't already in use (and were you using Linux, OS X, or anything UNIX-like, not any port below 1024).

For setting variables over the network, you might try the XMLRPC blocks, as described in another answer. These were recently deprecated, however.

See my other answer for discussion of alternative if performance issues arise.

Answer 3

Both Linux and Windows should have firewalls which might be blocking the connections.

You need to post the error messages displayed in gnuradio-companion.