Re: [Discuss-gnuradio] running OFDM on USRP2

Hi Tom,
In our case, even with script from Veljko, the OFDM receiver doesn't show any thing. And we always see "usrp2: failed to enable realtime scheduling". Do you think that will cause problem?

Thanks,
Bin

On Wed, Feb 3, 2010 at 12:57 PM, Anupama Purohit <anupama.purohit@gmail.com> wrote:

Hi Tom ,

Thanks , we did try the updated script from Veljko . It works though we have missing packets after a while ( as suggested in the forum we would play with the interpolation and decimation )  though the 2 USRP2s are directly connected .

 

We are still probing into the permissions issue as indicated though we ran with root permissions
( may be not in totality) , would keep posted on the later if we find something on the same

 

Thanks again ,

 

/Regards

 

On Wed, Feb 3, 2010 at 8:17 AM, Tom Rondeau <trondeau1122@gmail.com> wrote:

On Tue, Feb 2, 2010 at 4:34 PM, Anu000 <anupama.purohit@gmail.com> wrote:
>
> Hi,
> We did try the below command on two USRP2s coneected via a SMA Cable (Tx-Rx)
> with freq = 25M  however it returned the following error on both sides
>
> At Rx side it shows like the below -
>
> [root@GNURADIO1 ofdm]# ./benchmark_ofdm_rx.py -f 25M -d 256 --fft-length=64
> --occupied-tones=32 --cp-length=4
> usrp: failed to find usrp[0]
> Traceback (most recent call last):
>  File "./benchmark_ofdm_rx.py", line 210, in <module>
>    main()
>  File "./benchmark_ofdm_rx.py", line 199, in main
>    tb = my_top_block(rx_callback, options)
>  File "./benchmark_ofdm_rx.py", line 51, in __init__
>    self._setup_usrp_source()
>  File "./benchmark_ofdm_rx.py", line 70, in _setup_usrp_source
>    fusb_nblocks=self._fusb_nblocks)
>  File "/usr/lib/python2.6/site-packages/gnuradio/usrp/usrp_swig.py", line
> 1699, in source_c
>    return _usrp_swig.source_c(*args, **kwargs)
> RuntimeError: can't open usrp
>
> At Tx side -
> root@gnu2 ofdm]# ./benchmark_ofdm_tx.py -f 25M -i 512 --fft-length=64
> --occupied-tones=32 --cp-length=4
> usrp: failed to find usrp[0]
> Traceback (most recent call last):
>  File "./benchmark_ofdm_tx.py", line 217, in <module>
>    main()
>  File "./benchmark_ofdm_tx.py", line 190, in main
>    tb = my_top_block(options)
>  File "./benchmark_ofdm_tx.py", line 51, in __init__
>    self._setup_usrp_sink()
>  File "./benchmark_ofdm_tx.py", line 66, in _setup_usrp_sink
>    fusb_nblocks=self._fusb_nblocks)
>  File "/usr/local/lib/python2.5/site-packages/gnuradio/usrp/usrp_swig.py",
> line 2415, in sink_c
>    return _usrp_swig.sink_c(*args, **kwargs)
> RuntimeError: can't open usrp
>
> May we request somebody to support us at the earliest to resolve the above
> issue with either software or hardware .
>
> Thanks again,
> Anupama

This is because you do not have the right permissions set to talk to
the USRP2 as a non-root user. See the USRP2 FAQs on the GNU Radio web
page for how to fix this.

Tom

--
Thanks & Regards,
Anupama Purohit
972 697 8183 (M)

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