discuss-gnuradio
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Unable to tune Tx or Rx with XCVR2450 on USRP2


From: Josh Blum
Subject: Re: [Discuss-gnuradio] Unable to tune Tx or Rx with XCVR2450 on USRP2
Date: Thu, 28 Jan 2010 21:56:38 -0800
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.8pre) Gecko/20100120 Shredder/3.0.2pre



On 01/28/2010 09:17 PM, Ian Holland wrote:
Thanks Josh

This partially fixed the problem, in the sense that samples are now
displayed on the fft window when running usrp2_fft.py, and it no longer
says "channel 0 not receiving". However, it still fails to set the
frequency of the receiver. Also, when I run usrp_siggen.py, I still get
the same problem that the Tx frequency can't be set. In verbose mode,
the output of usrp_siggen.py is as below. Any ideas on what else could
be wrong?

Regards

Ian.

USRP interpolation rate: 16
USRP IF bandwidth: 6.25MHz
Set TX gain to: 15.0
Using auto-calculated mid-point frequency


The xcvr has a high band and a low band, which means there is a gap in the tunable frequency range for the xcvr. Therefore, the "auto-calculated mid-point frequency" is an invalid frequency for the xcvr. Pick a frequency in the high band or low band range:

#define LB_FREQ_MIN U2_DOUBLE_TO_FXPT_FREQ(2.3e9)
#define LB_FREQ_MAX U2_DOUBLE_TO_FXPT_FREQ(2.6e9)
#define HB_FREQ_MIN U2_DOUBLE_TO_FXPT_FREQ(4.8e9)
#define HB_FREQ_MAX U2_DOUBLE_TO_FXPT_FREQ(6.1e9)


Failed to set freq.
(...etc...)



Your firmware and fpga images on the sd card are probably out of sync.
You can find images here: http://gnuradio.org/releases/usrp2-bin/trunk/

and here are instructions on how to burn:
http://gnuradio.org/redmine/wiki/gnuradio/USRP2UserFAQ

-Josh

On 01/28/2010 06:14 PM, Ian Holland wrote:
Hi Matt

I have tried usrp2_fft.py -f 2.4G and also usrp2_fft.py -f 5.7G as you
suggest below. In both cases, the fft window opens but no trace is
displayed, and I see the following output in the terminal:

usrp2: channel 0 not receiving
usrp2::rx_sample() failed

I only recently received my USRP2s and XCVR2450s, which were shipped
at
the end of December. Are there any known issues with the firmware on
the
SD cards at this time, or do you have any other idea why I can't seem
to
tune frequencies on these cards?

Thanks

Ian.

-----Original Message-----
From: Matt Ettus [mailto:address@hidden
Sent: Friday, 29 January 2010 12:35 PM
To: Manav Seth
Cc: Ian Holland; address@hidden
Subject: Re: [Discuss-gnuradio] Unable to tune Tx or Rx with XCVR2450
on
USRP2



The -f argument to usrp2_fft.py is the frequency.  By putting "-f
1000"
you are telling the system to try to tune the xcvr2450 to 1 kHz.  The
specified range is 2.4-2.5 GHz and 4.9 to 5.9 GHz.  1 kHz is WAY
outside

of that range.  I would suggest you try something like:

usrp2_fft.py -f 5.7G

Matt

On 01/28/2010 05:35 PM, Manav Seth wrote:
Actually no...its always returning false...
when I use usrp2_fft.py with -f 1000 then output does come but still
it
is unable to set the initial frequency though it did receive.

I am still trying to figure out the problem...

On Thu, Jan 28, 2010 at 3:43 PM, Ian Holland
<address@hidden<mailto:address@hidden>>
wrote:

      On Wed, Jan 27, 2010 at 8:52 PM, Ian Holland

<address@hidden<mailto:address@hidden>>
      wrote:
      Hi All

      I have been trying to set the Tx and Rx frequencies when using
an
      XCVR2450 with a USRP2, but it seems these keep failing. A
snippet
of my
      source code is below for setting the Tx frequency.
      The output of this portion of code is "Failed to tune Tx", and
the
      frequencies are all 0, with spectrum_inverted being false.
      I have also tried to use usrp2_fft.py, and this fails saying
nothing is
      received on channel 0.
      Does anyone know what the problem could be?

      Thanks

      Ian.

      /* try tuning Tx to a test frequency */
                  double Fc = 2400000000.0;
                  usrp2::tune_result TxTuneResult;
                  bool successTx = device->set_tx_center_freq(Fc,
      &TxTuneResult);
                  if(successTx) {
                                       cout<<   "Tx Tune
Successful:\n";
                       cout<<   "    Baseband Frequency:"<<
      TxTuneResult.baseband_freq<<   "\n";
                       cout<<   "    DxC Frequency:"<<
      TxTuneResult.dxc_freq<<   "\n";
                       cout<<   "    Residual Frequency:"<<
      TxTuneResult.residual_freq<<   "\n";
                       cout<<   "    Spectrum Inverted:"<<
      (TxTuneResult.spectrum_inverted ? "true" : "false")<<   "\n";
                  }
                  else {
                                       cout<<   "Failed to tune Tx.\n";
                       cout<<   "    Baseband Frequency:"<<
      TxTuneResult.baseband_freq<<   "\n";
                       cout<<   "    DxC Frequency:"<<
      TxTuneResult.dxc_freq<<   "\n";
                       cout<<   "    Residual Frequency:"<<
      TxTuneResult.residual_freq<<   "\n";
                       cout<<   "    Spectrum Inverted:"<<
      (TxTuneResult.spectrum_inverted ? "true" : "false")<<   "\n";
                  }
                  cout<<   "\n";

      _______________________________________________

       >From: Manav Seth [mailto:address@hidden
      <mailto:address@hidden>]
       >Sent: Thursday, 28 January 2010 3:29 PM
       >To: Ian Holland
       >Cc: address@hidden<mailto:address@hidden>
       >Subject: Re: [Discuss-gnuradio] Unable to tune Tx or Rx with
XCVR2450
      on>USRP2

       >Ya, its failing for me too...set_tx_center_freq is always
failing
      (though I>am writing my code in python)..
       >not able to find the cause...

      Have you been able to get any of the pre-written scripts (e.g.
      usrp2_fft.py or usrp_siggen.py) working? I can't even get those
to
work.
      I tried usrp_siggen.py in verbose this morning and noticed again
it was
      unable to set the Tx frequency. Also, I think the error I had
mentioned
      above re usrp2_fft.py would be because the rx frequency couldn't
be set.

      I have tried two of the daughtercards on one USRP2, and one of
those two
      cards on the other USRP2, and still can't get it to set, though
it
      worked fine using the same code for the BasicTx and BasicRx.









_______________________________________________
Discuss-gnuradio mailing list
address@hidden
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio



_______________________________________________
Discuss-gnuradio mailing list
address@hidden
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio


_______________________________________________
Discuss-gnuradio mailing list
address@hidden
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio




reply via email to

[Prev in Thread] Current Thread [Next in Thread]