Forum: GNU Radio Receiving and then sending using USRP2

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675175af18f74772d42dd5ce1bf2dc8b?d=identicon&s=25 Per Zetterberg (Guest)
on 2009-04-09 16:55
(Received via mailing list)
Dear All,

I have copied rx_streaming_samples.cc from "usrp2/host/apps" to a local
directory, compiled and linked with libusrp2 etc. It works. However, in
a first small step towards transmitting with the usrp2 I added
"u2->set_tx_center_freq(1902.5e6, &tr)" just before the end of main (and
nothing more). The command fails.

In an effort to find the error we used wiresharc and were able to see
the command from the host being transmitted and a response being sent
from the usrp2. However, the host doesn't seem to be satisfied with the
received packet.

?

BR/
Per
D0072e69d706bb3ca211d33a1b536e2c?d=identicon&s=25 Johnathan Corgan (Guest)
on 2009-04-09 17:02
(Received via mailing list)
On Thu, 2009-04-09 at 16:47 +0200, Per Zetterberg wrote:

> I have copied rx_streaming_samples.cc from "usrp2/host/apps" to a local
> directory, compiled and linked with libusrp2 etc. It works. However, in
> a first small step towards transmitting with the usrp2 I added
> "u2->set_tx_center_freq(1902.5e6, &tr)" just before the end of main (and
> nothing more). The command fails.

Which version of the trunk software are you using?

Johnathan
745d8202ef5a58c1058d0e5395a78f9c?d=identicon&s=25 Eric Blossom (Guest)
on 2009-04-09 19:05
(Received via mailing list)
On Thu, Apr 09, 2009 at 04:47:07PM +0200, Per Zetterberg wrote:
> Dear All,
>
> I have copied rx_streaming_samples.cc from "usrp2/host/apps" to a local
> directory, compiled and linked with libusrp2 etc. It works. However, in
> a first small step towards transmitting with the usrp2 I added
> "u2->set_tx_center_freq(1902.5e6, &tr)" just before the end of main (and
> nothing more). The command fails.


> In an effort to find the error we used wiresharc and were able to see
> the command from the host being transmitted and a response being sent
> from the usrp2. However, the host doesn't seem to be satisfied with the
> received packet.

What daughterboard are you using?

What do tx_freq_min() and tx_freq_max() return?

Eric
675175af18f74772d42dd5ce1bf2dc8b?d=identicon&s=25 Per Zetterberg (Guest)
on 2009-04-14 10:42
(Received via mailing list)
On Thu, 2009-04-09 at 07:56 -0700, Johnathan Corgan wrote:
> Johnathan
>
10700

BR/
Per
675175af18f74772d42dd5ce1bf2dc8b?d=identicon&s=25 Per Zetterberg (Guest)
on 2009-04-14 11:14
(Received via mailing list)
On Thu, 2009-04-09 at 09:53 -0700, Eric Blossom wrote:
> > In an effort to find the error we used wiresharc and were able to see
> > the command from the host being transmitted and a response being sent
> > from the usrp2. However, the host doesn't seem to be satisfied with the
> > received packet.
>
> What daughterboard are you using?
>
RFX1800

> What do tx_freq_min() and tx_freq_max() return?

1.6GHz and 2.0GHz, respectively.


BR/
Per
675175af18f74772d42dd5ce1bf2dc8b?d=identicon&s=25 Per Zetterberg (Guest)
on 2009-04-15 11:06
(Received via mailing list)
Dear All,

I am trying to issue 50000 calls to tx_16sc (of 371 samples each i.e.,
one ETH packet per call) to the USRP2. I transmit a simple sinuswave. If
I set "send_now=1" in the metadata it works as expected and I can see
the signal on a spectrum analyzer. If I set send_now=0 I can only
occasionally see the signal pass and then for only very short time. Here
are some more details: I first receive a few frames to get the
time-stamp from the received frames, this timestamp is stored in the
variable last_time_stamp. Then I transmit using the code below (the
interpolation factor is set to 10). Is there anything I have
misunderstood ?

metadata.send_now=0;
metadata.start_of_burst=1;
metadata.end_of_burst=1;

int i1;
for (i1=0;i1<NO_ITER-1;i1++) {

    metadata.timestamp=last_time_stamp+10e6+i1*NO_SAMPLES*10;

    if (!u2->tx_16sc(0,
  buffer,
  NO_SAMPLES,
  &metadata)) {
   printf("Transmit data failed!\n");
      };
           metadata.start_of_burst=1;
     };

    metadata.end_of_burst=1;
    u2->tx_16sc(0,
     buffer,
     NO_SAMPLES,
    &metadata);

};


BR/
Per
908b26698752d141fda4c93e5ce45d9e?d=identicon&s=25 hanwen (Guest)
on 2009-09-24 19:22
(Received via mailing list)
Hi,

Have you got this issue with USRP2 solved.
We're now couping with the similar issue setting the tx_timestamp for
choosing a synchronized transmitting time for 2 usrp2.
We use sync_every_pps(true) for reseting the timestamp counter every 1
second with external PPS input. and set the timestamp to 99999999.
But it doesn't work when interporlation rate lower than 10.

Bests,
Hanwen


2009/4/15 Per Zetterberg <per.zetterberg@ee.kth.se>
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