On Fri, Jan 06, 2006 at 04:17:03PM -0500, Marcus Leech wrote: > I'm trying to morph wxgui/fftsink.py into a "strip chart" type sink for > RA use. > > I have most of the logic implemented (at least for a first experimental > pass). > > But I have questions about the appropriate plumbing. I'm going to > assume that > the sink will be available only in float, with essentially no > processing of the > incoming data stream other than displaying it appropriately. > > The following piece of "plumbing" from class fft_sink_f in fftsink.py > confuses me: > > s2p = gr.serial_to_parallel(gr.sizeof_float, fft_size) > one_in_n = gr.keep_one_in_n(gr.sizeof_float * fft_size, > max(1, > int(sample_rate/fft_size/fft_rate))) > fft = gr.fft_vfc(fft_size, True, True) > c2mag = gr.complex_to_mag(fft_size) > self.avg = gr.single_pole_iir_filter_ff(1.0, fft_size) > log = gr.nlog10_ff(20, fft_size, -20*math.log10(fft_size)) > sink = gr.message_sink(gr.sizeof_float * fft_size, self.msgq, > True) > > fg.connect (s2p, one_in_n, fft, c2mag, self.avg, log, sink) > gr.hier_block.__init__(self, fg, s2p, sink)
> Functionally, I understand what it's doing, but I don't know what > gr.hier_block.__init__(self,fg,s2p,sink) is > all about. This is initializing the superclass. The last two args correspond to the head and tail of the hierarchical block that we're defining. [FWIW, this will probably get refactored over the next couple of months. There are some things that it would be nice to do that this won't support.] > I think that for my purposes, all I need to do is to > lash-in a gr.message_sink to pass data events > to the plotting routine. That's the very last item in the fftsink > chain--the gr.message_sink. > > I think all I need to do instead of the above is: > > sink = gr.message_sink(gr.sizeof_float * 1, self.msgq, True) > fg.connect(sink) > > But what do I do with gr.hier_block.__init__(self, fg, s2p, sink) ??? Just leave it as is. Should work fine. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
