[Discuss-gnuradio] GRC programming problem--anyone with any bright ideas?

[Marcus D. Leech]

I've been working on a flow-graph for meteor-burst detection on VHF 
(more specifically using the NAVSPASUR "space fence" as a signal
  source).

Part of the flow-graph involves probes that run at several-Hz rate and 
decide whether to start recording signal-power data, based on
  triggering criteria.  This works just fine.  The 
trigger-detection/recording function also returns a filename (either 
/dev/null if not
  triggered, or a dynamically-generated filename otherwise).  The 
intention of this is to provide the filename for a gr_file_sink to use
  to record downsampled baseband data during triggering.  The problem, 
of course, is that if this variable is handed to gr_file_sink,
  it'll be re-opening files (either /dev/null or the "real" file) at a 
many-Hz rate, which is not the desired semantic.  So I modified gr_file_sink
  to check for a *change* in filename in the open() method, and only 
proceed with a re-open if the filename has changed.  This isn't really
  clean and elegant.

GRC doesn't lend itself particularly well to this type of processing.   
I suppose I could run the baseband streams into a vector sink, and have my
  poll function unload those vectors whenever the poll function is 
called.  Any hints on how to do that?


--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org