Re: [Discuss-gnuradio] GRC, Recording chunks of spectrum triggered on input signal level

[Vanush Vaswani]

All these workarounds seems hacky
Is there a paradigm that can handle this.

On Wed, Nov 19, 2014 at 8:17 AM, Staffan Bruce <address@hidden> wrote:
> It works, many thanks!
>
> It seems like the changing of a variable in itself does not trigger an
> update of other variables (that are depending on the first one), but using a
> button or probe will trigger an update of the variables that are depending
> on them. Could this be something to consider for GnuRadio/Companion, i.e.,
> dependencies between variables and assuring that they are updated when a
> change is occurring in one of them?
>
> Still, file sink notices the change of the variable it is depending on and
> that is enough. Now I have a good way of making separate recordings - great!
>
> ...and yes - time to start learning how to code.
>
> Regards,
>  Staffan
>
> -----Original Message----- From: madengr
> Sent: Monday, November 17, 2014 6:58 PM
> To: address@hidden
> Subject: Re: [Discuss-gnuradio] GRC, Recording chunks of spectrum triggered
> on input signal level
>
> If you are using an "if" statement to switch between filename and /dev/null,
> try putting the filename construction in the "if" statement, instead of a
> separate variable.  That may make it evaluate every time the "if" statement
> is called.
>
> My example used the LO frequency as part of the filename, and every time the
> QT GUI slider changed the LO, it probably updated the filename.
>
> If that does not work, maybe you can use a probe to examine a signal, say
> 10x a second.  Then the probe level() function could be used as part of the
> filename.  That would at least change it 10x a second.
>
> For the counter, maybe you could also use a probes to look at a signal
> before and after a N sample delay, where delay and sample rate is about the
> same time as your probe rate; then this pseudocode:
>
> if now.level() != delayed.level() then count = count +1
>
> At this point though you ought to delve into the Python.  As long as you are
> not using the QT GUI, the code is pretty straight forward.  You can use
> probes to pull values out of the flow and evaluate them in Python.
>
> Thanks,
> Lou
> KD4HSO
>
>
>
>
> Staffan wrote
>>
>> Hello,
>>
>> After some weekend experimenting I believe I have most (most...) of it
>> working. Sinking to a USB stick is not working so well by the way...
>> One thing that is still a challenge is how to set the filename. You
>> provided
>> a very good way of timestamping, but when I try this, it only evaluates
>> once - when I start the script. Is there any way to force re-evaluation of
>> a
>> variable?
>> In addition, it would be great to have some kind of a counter (variable, x
>> =
>> x + 1) that can be updated depending on a state change - for example when
>> a
>> trigger event occurrs. I tried some different versions, but mainly ended
>> up
>> in circular references...
>>
>> Any suggestions would be highly appreciated!
>>
>> Regards,
>>   Staffan
>
>
>
>
>
>
> --
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> Sent from the GnuRadio mailing list archive at Nabble.com.
>
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