Capturing data to file

GNU Radio
1

Has anybody had any experience using the capture_to_file.py code from
KD7LMO?
(http://kd7lmo.net/ground_gnuradio_software.html) I am interested in
the
functionality to set up an IF frequency and bandwidth and dump the data
to a
file. When I have attempted to run the program I have encountered the
following error…

[jjw27370@localhost ~]$ ./capture_to_file.py narrowband_256k_complex.dat
10.7 250 30
Capturing 7680000 samples
Traceback (most recent call last):
File “./capture_to_file.py”, line 67, in ?
main (sys.argv[1:])
File “./capture_to_file.py”, line 63, in main
fg = build_graph (filename, IF_freq_hz, decim_rate, samples)
File “./capture_to_file.py”, line 38, in build_graph
src = usrp.source_c (0, decim, 1, mux)
File “/home/jjw27370/gr/lib/python2.4/site-packages/gnuradio/usrp.py”,
line 242, in init
fpga_filename, firmware_filename)
File
“/home/jjw27370/gr/lib/python2.4/site-packages/gnuradio/usrp1.py”,
line 1208, in source_c
return _usrp1.source_c(*args)
TypeError: in method ‘source_c’, argument 4 of type ‘int’

It seems there is something wrong with the way that mux is declared in
the
capture_to_file.py code (0xf0f0f0f0). According to Dawai Shen’s
tutorial on
USRP (http://www.nd.edu/~dshen/GNU/Tutorial/4.html) 0xf0f0f0f0 should be
a
valid combination to use. Maybe I am missing some trivial detail or
maybe
this code was designed for an older version of GNU Radio, but if anybody
could shed some light on this issue or maybe knows of a better program
for
capturing data to a file, it would be helpful.

Thanks,
John

View this message in context:
http://www.nabble.com/Capturing-data-to-file-t1325900.html#a3538604
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2

It seems there is something wrong with the way that mux is declared in the
capture_to_file.py code (0xf0f0f0f0).

The problem is that Python promotes that value to a bignum because it
doesn’t fit into an int (as a positive number). This was a recent
change
to Python, which is great for numeric users but has caused small
problems
for people making bitmasks.

John
3

On Wed, Mar 22, 2006 at 10:51:19AM -0800, jjw wrote:

Traceback (most recent call last):
line 1208, in source_c
capturing data to a file, it would be helpful.

Thanks,
John

May I suggest you try gnuradio-examples/python/usrp/usrp_rx_cfile.py?
It handles all daughterboards, and basically just “does the right
thing”.

Eric

4

John,
Try this:

…
from gnuradio import gru
…
mux = gru.hexint(0xf0f0f0f0)
…

It works for me…

Angilberto.

— jjw [email protected] wrote:

File “./capture_to_file.py”, line 38, in
build_graph
src = usrp.source_c (0, decim, 1, mux)
File

“/home/jjw27370/gr/lib/python2.4/site-packages/gnuradio/usrp.py”,

line 242, in init
fpga_filename, firmware_filename)
File

“/home/jjw27370/gr/lib/python2.4/site-packages/gnuradio/usrp1.py”,

USRP (http://www.nd.edu/~dshen/GNU/Tutorial/4.html)
John

View this message in context:

http://www.nabble.com/Capturing-data-to-file-t1325900.html#a3538604

Sent from the GnuRadio forum at Nabble.com.

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