Hello Martin Braun: I'm not sure what you mean. There is no set_center_freq() method in gr_sig_source_c.
When you say the best way to implement frequency hopping is to "use a larger bandwidth and do the tuning digitally", you mean to do the tuning in software in the Python flowgraph using Gnuradio blocks? Thanks. Steve McMahon --- On Fri, 12/17/10, Martin Braun <[email protected]> wrote: > From: Martin Braun <[email protected]> > Subject: Re: [Discuss-gnuradio] time to reconfigure a block in flowgraph > To: [email protected] > Date: Friday, December 17, 2010, 3:36 AM > On Thu, Dec 16, 2010 at 05:32:23PM > -0800, Steve Mcmahon wrote: > > Hello: > > > > I need some help on a timing issue. > > > > I have a timer running on a separate thread which > changes parameters in my flow graph every 100ms or 200ms. > When I change the frequency of my Signal Source by using > gr.sig_source_c.set_frequency(), the timer thread is still > able to fire every 100ms or 200ms and change the tone > frequency every cycle. However, when I try to also change > the center frequency in the timer thread with > usrp2.sink_32fc.set_center_freq(), it cannot keep up and > often takes more than 100ms or 200ms. > > > > How long do functions such as > usrp2.sink_32fc.set_center_freq() take to execute? Do I need > to to gr.lock() and gr.unlock() my flowgraph before changing > these kind of parameters? How can I change parameters every > 100ms? > > Not the most general answer you can get, but if you want to > do *precise* > retuning (e.g. for frequency hopping) to my best knowledge > the way to go > is to use a larger bandwidth and do the tuning digitally. > You don't have > to use lock() for retuning the usrp (just as you don't have > to do so for > calling set_center_freq() on the sig_source). > > Cheers, > MB > > -- > Karlsruhe Institute of Technology (KIT) > Communications Engineering Lab (CEL) > > Dipl.-Ing. Martin Braun > Research Associate > > Kaiserstraße 12 > Building 05.01 > 76131 Karlsruhe > > Phone: +49 721 608-3790 > Fax: +49 721 608-6071 > www.cel.kit.edu > > KIT -- University of the State of Baden-Württemberg and > National Laboratory of the Helmholtz Association > > > -----Inline Attachment Follows----- > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
