Re: Sending a message to 'osmocom source' block does not work

[Marcus Müller]

Hi Kimmo,

as far as I know, the gr-osmosdr blocks don't have such a message port,
and a `git grep "[\"']command[\"']" does confirm that suspicion.

Best regards,
Marcus

On 04.02.22 16:00, Kimmo Lehtinen wrote:
> Hi all,
>
> I am trying to send a messsage from a Python block (of type gr.sync_block) to
> 'osmocom source', so that I can change the frequency of the receiver.
>
> First, I have in the Python block the command
>
> self.message_port_register_out(pmt.intern('msg_out'))
>
> and then in the work-function of the Python block I give
>
> self.freq = 80e6
> key = pmt.intern("freq")
> value = pmt.to_pmt(self.freq)
> self.message_port_pub(pmt.intern('msg_out'), pmt.cons(key, value))
>
> Then, if I connect the 'msg_out' port of the Python block to 'print' port of the
> 'Message debug' block, it prints
>
> ******* MESSAGE DEBUG PRINT ********
> (freq . 8e+07)
>
> But if I connect the 'msg_out' port to 'command' port of the 'osmocom source'
> block, I get the following error:
>
> --------
> Could not find port: command in:
>
> Traceback (most recent call last):
>    File "/home/kimmo/Hydra-plain-fft/Hydra_options.py", line 718, in <module>
>      main()
>
>    File "/home/kimmo/Hydra-plain-fft/Hydra_options.py", line 696, in main
>      tb = top_block_cls()
>
>    File "/home/kimmo/Hydra-plain-fft/Hydra_options.py", line 410, in __init__
>      self.msg_connect((self.epy_block_2, 'msg_out'), (self.osmosdr_source_0, 
> 'command'))
>
>    File "/usr/lib/python3/dist-packages/gnuradio/gr/hier_block2.py", line 60, 
> in wrapped
>      func(self, src.to_basic_block(), srcport, dst.to_basic_block(), dstport)
>
>    File "/usr/lib/python3/dist-packages/gnuradio/gr/hier_block2.py", line 132, 
> in msg_connect
>      self.primitive_msg_connect(*args)
>
>    File "/usr/lib/python3/dist-packages/gnuradio/gr/runtime_swig.py", line 4541, in 
> primitive_msg_connect
>      return _runtime_swig.top_block_sptr_primitive_msg_connect(self, *args)
>
> RuntimeError: invalid msg port in connect() or disconnect()
> --------
>
>
> In the genereted Python file there are the following commands which are related 
> to
> message passing:
>
> self.msg_connect((self.epy_block_2, 'msg_out'), (self.blocks_message_debug_0, 
> 'print'))
> self.msg_connect((self.epy_block_2, 'msg_out'), (self.osmosdr_source_0, 
> 'command'))
>
> I am using Gnuradio 3.8.1.0 (Python 3.8.10) in Ubuntu 20.04.3 LTS
>
> cheers, Kimmo

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