[Discuss-gnuradio] Rewiring the flowgraph

[Patrick Strasser]

Hello!

I tried to rewire a flwograph, but with no success:

from gnuradio import gr, audio
fg =gr.flow_graph()
src = gr.sig_source_f(48000, gr.GR_SIN_WAVE, 440, 1)
sink = audio.sink(48000)
fg.connect(src, sink)
fg.start()
fg.stop()
fg.disconnect(src, sink)
fg.connect(src, sink)
fg.start()
Traceback (most recent call last):
  File "<input>", line 1, in ?
  File 
"/usr/local/lib/python2.3/site-packages/gnuradio/gr/flow_graph.py", line 
88, in start
    self._setup_connections ()
  File 
"/usr/local/lib/python2.3/site-packages/gnuradio/gr/flow_graph.py", line 
117, in _setup_connections
    self.validate ()
  File 
"/usr/local/lib/python2.3/site-packages/gnuradio/gr/basic_flow_graph.py", 
line 165, in validate
    raise ValueError, ("%s::check_topology (%d, %d) failed" % (m, 
ninputs, noutputs))
ValueError: <gr_block audio_alsa_sink (1)>::check_topology (1, 0) failed

Is it possible to do something like this? I guess fg.disconnect is meant 
to enable some new connections to another block, but I've has no success 
until now.

I'd like to change the flowgraph to enable or disable different 
branches, say FM or AM decoding, on the fly. Another use would be to 
record some signal and in parallel listen to what you record. Instead of 
muting the sound, disconnect it and listen to your favourite music instead.

Patrick
--
Engineers motto: cheap, good, fast: choose any two
Patrick Strasser <patrick dot strasser at  tugraz dot at>
Student of Telematik, Techn. University Graz, Austria