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On 03/20/2020 05:10 PM, Vitt Benv
wrote:
Good evening,
I'm trying to make a multimode receiver using a PlutoSDR; all the demodulation and visualization parts work correctly.
Now I would like to use a click'n-point tuning and as a result I have tried to understand something more about the use of controlports.
I followed some tutorials and made a custom block (myblock.py "Message splitter") which receives the message generated by double clicking on the waterfallas an input and
generates a message to be sent to the Frequency Xlating Fir Filter block, which consists of an offset between the center frequency (fx) and the frequency generated by the double click.
I state that by controlling this block with a slider (fx_tune) everything works correctly, but using the outgoing message the set frequency is completely incorrect.
In the embedeed block I perform an output of the variables involved directly on the console and everything "apparently" is correct.
Any ideas / suggestions?
Attached is the .grc file, the source of the "Message splitter" block and a printscreen of the blocks (I have eliminated what is unnecessary and already functional).
Thanks in advance,
Vittorio, I3VFJ
Quick look suggests that you're confused about how the
freq-xlating-filter works. The center frequency is the *baseband*
frequency, not
the RF frequency that your hardware is tuned to. Gnu Radio,
internally, deals with basebanded signals, typically, and the RF
frequencies
are purely hardware-on-the-outside thing.
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