Can't set center frequency of USRP2 w/DBSRX

GNU Radio
1

We’re new to gnuradio and have a shiny USRP2 with a DBSRX daughterboard.
More details are below.

The system is kind of working, but usrp2_fft.py reports Failed (or
Invalid if there’s a typo) for every frequency we enter regardless of
whether it’s in the supported range or not. Oddly, the entered value
does affect the spectrum display and the signal we’re supplying does
show up sometimes, but the relationship between the frequency we enter
and our generated signal is unclear to us.

srp2_probe returns sensible information:

Converter Rate: 100000000 Hz
Gain Range: 0.0 - 84.0 step 1.0
Freq Range: 500000000 Hz - 2600000000 Hz

I’ve looked at the source and don’t see an obvious way to get more
information on the failure. Is there one?
Are there other diagnostic tools we should try?

We’re using raw ethernet (and running everything with sudo). Should we
use UDP or UHD instead?

Any tips would be much appreciated.

-Marc

Configuration details:

Ubuntu 10.04
GNU Radio 3.3.0 from
http://ftp.gnu.org/gnu/gnuradio/gnuradio-3.3.0.tar.gz
Installed using the Lucid install script at
http://gnuradio.org/redmine/wiki/gnuradio/UbuntuInstall.
We originally installed the prebuilt 3.2.2 package available via the
Synaptic Package Manager, but uninstalled it.

FPGA: u2_rev3-20100603.bin
Firmware: txrx_raw_eth_20100608.bin
DBSRX EEPROM: burn_dbsrx_eeprom.bin dated July 14, 2010
All from
http://code.ettus.com/redmine/ettus/projects/public/wiki/U2binaries

2

On 07/26/2010 11:58 AM, Marc E. wrote:

srp2_probe returns sensible information:
use UDP or UHD instead?
Installed using the Lucid install script

Discuss-gnuradio mailing list
[email protected]
Discuss-gnuradio Info Page

Did you do the conversion steps necessary to get a DBS_RX to work with
the USRP2?

http://gnuradio.org/redmine/wiki/gnuradio/USRP2DBSRXModification

3

On Jul 26, 2010, at 11:29 AM, Marcus D. Leech wrote:

Did you do the conversion steps necessary to get a DBS_RX to work with the USRP2?

On Jul 26, 2010, at 11:24 AM, Josh B. wrote:

Did you do the hardware mod where you move the resistor?

http://gnuradio.org/redmine/wiki/gnuradio/USRP2DBSRXModification

Thanks Josh and Marcus! That was indeed the problem and we’re up and
running. We mistakenly assumed our brand new hardware, ordered together,
would already have the appropriate mods. Never assume…

-Marc

4

On Jul 26, 2010, at 4:56 PM, Marcus D. Leech wrote:

Something that would be useful would be a place for people to pick up
the necessary burn_dbsrx_eeprom.bin
without having to compile the C code. Just sayin’

I found it at
http://code.ettus.com/redmine/ettus/projects/public/wiki/U2binaries.
It’s the last one in the Firmware Images section.

-Marc

5

On 07/26/2010 06:05 PM, Marc E. wrote:

-Marc

Ah! Missed it the first few times I went there–thanks!

6

On 07/26/2010 03:20 PM, Marc E. wrote:

Thanks Josh and Marcus! That was indeed the problem and we’re up and
running. We mistakenly assumed our brand new hardware, ordered
together, would already have the appropriate mods. Never assume…

-Marc

You’re welcome.

Something that would be useful would be a place for people to pick up
the necessary burn_dbsrx_eeprom.bin
without having to compile the C code. Just sayin’

–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium