Re: [Discuss-gnuradio] Help needed with message ports [success]

[Volker Schroer]

Just to report the solution, as it me be usefull for others.

My block was an hier2 block. Hier2 blocks can't handle messages 
directly, they only can serve as a proxy.

So I added a gr::block with no inputs and outputs ( yes, this is 
possible, I did not know before ) that could handle the message.

From my hier2 block I routed the message to my new block and everything 
works fine.

The details can be seen on github

https://github.com/dl1ksv/gr-fcdproplus/tree/gnuradio3.8

Many thanks to MLD, who pointed me into the right direction.

-- Volker



Am 20.07.2018 um 12:28 schrieb Volker Schroer:
> Hi,
>
> I'm trying to add an message port to my  working oot module fcdproplus 
> to be able to control the frequency by an message from a qtgui sink.
>
> I used the analog signal source as guide and implemented a message sink 
> in the grc description, registered the in port, and defined  a handler 
> function like described in the tutorial.
>
> I can run my example of a simple fm receiver as before, but when I 
> connect the message out port of a qtgui sink to my message in port of my 
> oot block,
>
> I get the following error message:
>
>
> ./FMRadio.py
> INFO: Audio source arch: alsa
> Funcube Dongle Pro+ found as: plughw:3,0
> Dongle sucessfully initialized
> Result of Action :+++++
> FCDAPP 20.03
>   Lna gain enabled
>   Mixer gain enabled
> If gain set to: 10
> Set Frequency to: 94.3 KHz, corrected to: 94300 Khz
> INFO: Audio sink arch: alsa
> Traceback (most recent call last):
>    File "./FMRadio.py", line 277, in <module>
>      main()
>    File "./FMRadio.py", line 266, in main
>      tb.start()
>    File 
> "/usr/local/gnuradio/lib64/python2.7/site-packages/gnuradio/gr/top_block.py", 
> line 109, in start
>      top_block_start_unlocked(self._impl, max_noutput_items)
>    File 
> "/usr/local/gnuradio/lib64/python2.7/site-packages/gnuradio/gr/runtime_swig.py", 
> line 5678, in top_block_start_unlocked
>      return _runtime_swig.top_block_start_unlocked(r, max_noutput_items)
> RuntimeError: fcdproplus(3): insufficient connected output ports (1 
> needed, 0 connected)
>
> These are the connections:
>
>
>         ##################################################
>          # Connections
>          ##################################################
>          self.msg_connect((self.qtgui_sink_x_0, 'freq'), 
> (self.fcdproplus_fcdproplus_0, 'freq'))
>          self.connect((self.analog_fm_demod_cf_0, 0), 
> (self.audio_sink_0, 0))
>          self.connect((self.analog_fm_demod_cf_0, 0), 
> (self.audio_sink_0, 1))
>          self.connect((self.fcdproplus_fcdproplus_0, 0), 
> (self.low_pass_filter_0, 0))
>          self.connect((self.fcdproplus_fcdproplus_0, 0), 
> (self.qtgui_sink_x_0, 0))
>          self.connect((self.low_pass_filter_0, 0), 
> (self.analog_fm_demod_cf_0, 0))
>
> If I remove the line
>
> self.msg_connect((self.qtgui_sink_x_0, 'freq'), 
> (self.fcdproplus_fcdproplus_0, 'freq'))
>
>
> from my python script he error message disappears.
>
> What am I doing wrong?
>
>
> Any help is appreciated.
>
> -- Volker
>
>
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