Re: [Discuss-gnuradio] Unable to receive anything on receiver window !

[Nick Foster]

On Tue, 2011-07-26 at 12:22 -0400, saketh kumar wrote:
> Hey 
> 
>   I am working on USRP N200 with RFX2400. My set up includes two USRPs
> connected to two computers. I want them to communicate using
> uhd_benchmark_tx/rx.py codes. Initially I set up my receiver side by
> running uhd_benchmark_rx.py and it's done! The I shift to transmitter
> side and run uhd_benchmark_tx.py. It starts to transmit ( it is shown
> on window as ........................................ ) but I cannot
> receive anything on receiver window. So, my Question is what I am
> transmitting is correct or not ? If yes, then why not I am able to
> receive anything on receiver side.
> This is how it looks on both the sides.


Well, my first guess is that it could be because you're transmitting and
receiving 2GHz apart. Take a closer look at those warnings. The
frequencies you are trying to use (242MHz) are far outside the range
your daughterboard supports.

--n

> 
> RECEIVER :
> 
> address@hidden:~/gnuradio/gnuradio-examples/python/uhd_benchmark
> $ ./uhd_benchmark_rx.py -m gmsk -r 500k -v -S 2 --rx-freq=242M -F 10
> linux; GNU C++ version 4.4.5; Boost_104200; UHD_003.001.002-ba0e3c8
> 
> receiver: 
> -- Opening a USRP2/N-Series device...
> -- Current recv frame size: 1472 bytes
> -- Current send frame size: 1472 bytes
> -- mboard0 is MIMO master
> 
> UHD Warning:
>     Unable to set the thread priority. Performance may be negatively
> affected.
>     Please see the general application notes in the manual for
> instructions.
>     EnvironmentError: OSError: error in pthread_setschedparam
> RX antenna: TX/RX
> USRP Source: <gr_block gr uhd usrp source (2)>
> Samplerate:  250000.0
> 
> UHD Warning:
>     The hardware does not support the requested RX frequency:
>     Target frequency: 242.000000 MHz
>     Actual frequency: 2342.000000 MHz
> 
> UHD Warning:
>     The hardware does not support the requested RX frequency:
>     Target frequency: 242.000000 MHz
>     Actual frequency: 2342.000000 MHz
> >>> gr_fir_fff: using SSE
> bits per symbol = 1
> M&M clock recovery omega = 2.000000
> M&M clock recovery gain mu = 0.175000
> M&M clock recovery mu = 0.500000
> M&M clock recovery omega rel. limit = 0.005000
> frequency error = 0.000000
> 
> Receive Path:
> modulation:      gmsk_demod
> bitrate:         500kb/s
> samples/symbol:  2.0000
> Warning: Failed to enable realtime scheduling.
> 
> TRANSMITTER:
> 
> address@hidden:~/gnuradio/gnuradio-examples/python/uhd_benchmark
> $ ./uhd_benchmark_tx.py -m gmsk --size=100 -M 1 -r 500k
> --tx-amplitude=0.5 -v -S 2 --tx-freq=242M -F 10
> linux; GNU C++ version 4.4.5; Boost_104200; UHD_003.001.002-5239879
> 
> sender: 
> -- Opening a USRP2/N-Series device...
> -- Current recv frame size: 1472 bytes
> -- Current send frame size: 1472 bytes
> 
> UHD Warning:
>     The recv buffer could not be resized sufficiently.
>     Target sock buff size: 50000000 bytes.
>     Actual sock buff size: 131071 bytes.
>     See the transport application notes on buffer resizing.
>     Please run: sudo sysctl -w net.core.rmem_max=50000000
> 
> UHD Warning:
>     The recv buffer could not be resized sufficiently.
>     Target sock buff size: 50000000 bytes.
>     Actual sock buff size: 131071 bytes.
>     See the transport application notes on buffer resizing.
>     Please run: sudo sysctl -w net.core.rmem_max=50000000
> -- mboard0 is MIMO master
> 
> UHD Warning:
>     Unable to set the thread priority. Performance may be negatively
> affected.
>     Please see the general application notes in the manual for
> instructions.
>     EnvironmentError: OSError: error in pthread_setschedparam
> TX antenna: TX/RX
> USRP Sink: <gr_block gr uhd usrp sink (2)>
> sampling frequency:  1M
> 
> UHD Warning:
>     The hardware does not support the requested TX frequency:
>     Target frequency: 242.000000 MHz
>     Actual frequency: 4442.000000 MHz
> 
> UHD Warning:
>     The hardware does not support the requested TX frequency:
>     Target frequency: 242.000000 MHz
>     Actual frequency: 4442.000000 MHz
> >>> gr_fir_fff: using SSE
> bits per symbol = 1
> Gaussian filter bt = 0.35
> Tx amplitude     0.5
> modulation:      gmsk_mod
> bitrate:         500kb/s
> samples/symbol:  2.0000
> Warning: failed to enable realtime scheduling
> ...........U....................................................................................................................................................
> 
> Thanks in advance
> 
> -- 
> Saketh Kumar
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