Receiving data from two rx boards on USRP simultaneously

GNU Radio
1

Hi all,
I have a shiny new USRP with two dbsrx daughterboards installed. We want
to
use this as a demo for a 2-element interferometer. Ideally I just want
to
capture the raw data, with something like the usrp_rx_cfile.py program,
where the samples from each board are interleaved. However,
usrp_rx_cfile.py only allows you to choose Rx A or B, not both. (At
least
according to the usage help.)

Any suggestions for how I can (easily) capture from both Rx’s
simultaneously?

Thanks,
Randall.

2

Hi,

Re-sending this request after no replies. It is becoming urgent that I
sort
this out. I’m willing to reward helpful answers with pizza and/or beer.
:slight_smile:
There appears to be something akin to this functionality in the
now-obsolete
radio-astronomy package, but my python (and the documentation) is not
good
enough to sort out what is going on.

Thanks in advance,
Randall.

3

Any suggestions for how I can (easily) capture from both Rx’s
simultaneously?

use gnuradio-companion (grc) … its a nice graphical way to create
your flowgraph

If you are not using the UHD driver for your USRP, then you are looking
for the:

[USRP] → USRP Dual Source
[Sink] → File Sink
[Stream Conversion] → Interleave

For UHD, use [UHD] → UHD: Multi USRP Source instead of the USRP Dual
Source

If you are looking to get started with gnuradio-companion, check out
the example *.grc files under:

<GNURADIO_SRCDIR>/gnuradio-examples/grc/demod/

http://gnuradio.org/redmine/wiki/1/GNURadioCompanion

Jason

4

On 02/08/2011 11:45 PM, Randall W. wrote:

Any suggestions for how I can (easily) capture from both Rx’s
simultaneously?

Put a small app together in GRC with the dual-usrp source (or
alternatively, uhd source block) and a file sink block. Nothing to it.

-Josh