Ryan Seal wrote:
I have been working on a wxWidget based oscilloscope/spectrum widget
and have a few questions:
First, let me cover my idea of an oscilloscope/FFT program:
1. Data is provided from a source (USRP or file).
2. Data is formatted to fit the plotting window (transform matrix).
3. Data is sent to the plotting widget at specified intervals for
display.
I am a little confused as to how this should be handled when converted
to Python. I could write 2 or 3 classes and let the main plotting
widget handle the entire show; or I could break this up and a small
Python module would combine these objects separately. To me, I view
this as a "sinking" object and a single widget would provide
everything. But I don't want to continue without some sort of
feedback. At this point, I have a resizable window with ticks, a grid,
and a few labels and have plotted some test data and am happy with the
performance so far.
A few more specific questions:
1. Where/How do I access the USRP data stream (at the C++ level) and
is the data buffered in a way (P/C model) that allows me to know which
buffer is being filled and which one is ready to be read, overflows,
underflows, etc...?
2. Is there a standard data type (at the C++ level) that I should be
using when loading/manipulating the data ( valarray, vector,
pointers, gr_xxxxx, etc...)?
3. Is wxWidgets pretty much the standard for GNURadio development? I
have been looking around at other toolkits trying to find a good
reason to move from QT (for various reasons) and it appears that FLTK
is gaining momentum with other groups. Has anyone considered this? Or
are there compatibility reasons for not going this route?
I am concerned with the C++ aspect of the USRP because I want to
integrate this card with my current system for use with radar (305-m
dish). I currently use another card (overpriced garbage IMHO) that
dumps blocks of data into shared memory (up to 40MBPS) and I can then
run multiple processes capable of processing, storing, viewing data in
real-time. I should be able to replace the current digital receiver
card with the USRP (assuming I modify the FPGA to provide a triggered
mode) and dump this data in a similar manner.
Thanks,
Ryan
Some of the stuff in gr-radio-astronomy might be helpful to you, at
least in terms of your display widgets.
The Continuum display in usrp_ra_receiver.py receives data once per
second and displays it, by virtue of the
fact that the final IIR filter is arranged to always decimate down to
1Hz, with the parameters of the IIR filter
being user-settable.
Hey, when I was at the SARA meeting at Green Bank this summer, I met
Carmen Pantoja, who's
been involved with science at Arecibo. Some day, I'll take her up on
her offer of hospitality
in Puerto Rico, and demonstrate Gnu Radio/USRP/gr-radio-astronomy at
Arecibo.
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
