Re: [Discuss-gnuradio] gr_bin_statistics and usrp_spectrum_sense

[Martin Dvh]

Hi Eric,

I have the same problem Angilberto Muniz had with the new gr_bin_statistics and 
usrp_spectrum_sense.
Angilberto Muniz Sb wrote:
> Humm... I've put some 'prints' in the 'set_freq' and
> 'set_next_freq' functions and came to the conclusion
> that those functions are never called !
I get exactly the same.

I tried to understand the advanced python magic that is going on but that takes 
a bit of studying.

Before I do that.
Does this trick only work with specific python/swig/gcc versions or does it 
have smp issues?
I use the following:

uname -r
2.6.16-2-k7-smp

$ swig-1.3 -version

SWIG Version 1.3.24
Copyright (c) 1995-1998
University of Utah and the Regents of the University of California
Copyright (c) 1998-2004
University of Chicago
Compiled with g++ [i686-pc-linux-gnu]

$ python -V
Python 2.3.5

$ gcc -v
Reading specs from /usr/lib/gcc-lib/i486-linux/3.3.5/specs
Configured with: ../src/configure -v 
--enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr 
--mandir=/usr/share/man
--infodir=/usr/share/info --with-gxx-include-dir=/usr/include/c++/3.3 
--enable-shared --enable-__cxa_atexit --with-system-zlib --enable-nls
--without-included-gettext --enable-clocale=gnu --enable-debug 
--enable-java-gc=boehm --enable-java-awt=xlib --enable-objc-gc i486-linux
Thread model: posix
gcc version 3.3.5 (Debian 1:3.3.5-13)

These worked fine for gnuradio so far.

Greetings,
Martin

> 
> Angilberto.
> 
> --- Angilberto Muniz Sb <address@hidden> wrote:
> 
> 
>>Hi Eric,
>>
>>In the 'main_loop' of 'usrp_spectrum_sense.py' it
>>says
>>that m.center_freq is the current tunning/tunned
>>freq
>>and that m.data is the mag-squared of the FFT.
>>
>>When I run it I always get:
>>
>>0 (Zero) as the 'm.center_freq' and some numbers out
>>of the m.data structure (seems ok). Was not
>>'center_freq' supposed to reflect the actual tunned
>>freqquency?
>>
>>I've just inserted the following code into
>>'main_loop'
>>of "usrp_spectrum_sense.py":
>>
>>print m.center_freq, m.data[0], m.data[1]
>>
>>My setup: gnuradio latest version out of SVN.
>>OS: Umbuntu-LTS
>>
>>Thankx,
>>
>>Angilberto.
>> 
>>
>>--- Eric Blossom <address@hidden> wrote:
>>
>>
>>>Hi Folks,
>>>
>>>I wanted to let you know that I've checked in some
>>>code that should be
>>>useful for building "spectrum sensing"
>>
>>applications,
>>
>>>or for that
>>>matter, anything that needs to scan across a wide
>>>chunk of RF (bigger
>>>than you can get across the USB in a single
>>
>>chunk).
>>
>>>There are two primary pieces:
>>>
>>>(1)
>>>gnuradio-core/src/lib/general/gr_bin_statistics_f,
>>>which combines
>>>statistics gathering with a state machine for
>>>controlling the tuning
>>>
>>>and
>>>
>>>(2)
>>>
>>
>>gnuradio-examples/python/usrp/usrp_spectrum_sense.py
>>
>>>which is
>>>an application (closer to a skeleton) that ties it
>>>all together.
>>>
>>>
>>>
>>>address@hidden usrp]$ ./usrp_spectrum_sense.py --help
>>>usage: usrp_spectrum_sense.py [options] min_freq
>>>max_freq
>>>
>>>options:
>>>  -h, --help            show this help message and
>>>exit
>>>  -R RX_SUBDEV_SPEC,
>>
>>--rx-subdev-spec=RX_SUBDEV_SPEC
>>
>>>                        select USRP Rx side A or B
>>>(default=A)
>>>  -g GAIN, --gain=GAIN  set gain in dB (default is
>>>midpoint)
>>>  --tune-delay=SECS     time to delay (in seconds)
>>>after changing frequency
>>>                        [default=0.001]
>>>  --dwell-delay=SECS    time to dwell (in seconds)
>>>at a given frequncy
>>>                        [default=0.01]
>>>  -F FFT_SIZE, --fft-size=FFT_SIZE
>>>                        specify number of FFT bins
>>>[default=256]
>>>  -d DECIM, --decim=DECIM
>>>                        set decimation to DECIM
>>>[default=16]
>>>  --real-time           Attempt to enable
>>
>>real-time
>>
>>>scheduling
>>>  -B FUSB_BLOCK_SIZE,
>>>--fusb-block-size=FUSB_BLOCK_SIZE
>>>                        specify fast usb block
>>
>>size
>>
>>>[default=0]
>>>  -N FUSB_NBLOCKS, --fusb-nblocks=FUSB_NBLOCKS
>>>                        specify number of fast usb
>>>blocks [default=0]
>>>
>>>
>>>address@hidden usrp]$ ./usrp_spectrum_sense.py -R b -F
>>
>>256
>>
>>>902M 928M
>>>
>>>
>>>You may want to subclass gr_bin_statistics_f, it
>>>currently just
>>>keeps track of the maximum power in each FFT bin.
>>>
>>>You'll also want to play with the --tune-delay and
>>>--dwell-delay
>>>command line options to determine appropriate
>>>values.  --tune-delay
>>>should include time for the front end PLL to
>>
>>settle,
>>
>>>plus time for the
>>>new samples to propagate through the pipeline. 
>>
>>The
>>
>>>default is 1ms,
>>>which is probably in the ballpark on the RFX-*
>>>boards.  The TV RX
>>>board is much slower.  The tuner data sheets says
>>
>>it
>>
>>>could take 100ms to
>>>settle.  YMMV.  Please test and let us know what
>>
>>you
>>
>>>find.
>>>--dwell-delay says how long you want to "stare" at
>>>any particular window.
>>>
>>>
>>>Let me know if you've got any questions.  As
>>
>>always,
>>
>>>patches are welcome ;)
>>>
>>>
>>>When we've got the inband-signaling in place,
>>
>>we'll
>>
>>>be able to
>>>pipeline the tuning and our effective scanning
>>
>>rate
>>
>>>will increase.
>>>
>>>Eric
>>>
>>>
>>>_______________________________________________
>>>Discuss-gnuradio mailing list
>>>address@hidden
>>>
>>
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> 
>>
>>
>> 
>>
> 
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