Re: QT GUI Time Sink graph refresh rate

Ah, by the way, could you try the following dirty hack:

1. Copy the generated update_period.py file.
2. Find the place where self.blocks_throttle_0 = ... is done
3. after that, insert
self.blocks_throttle_0.set_max_noutput_items(int(samp_rate/100))

and report whether that works?

Best regards,
Marcus

On 30.12.21 13:54, Marcus Müller wrote:
> Exactly! Chances are even that the Throttle regularly sees very large input blocks, e.g.
> 8192 items at once, and then decides to sleep for loooooong before telling GNU Radio it's
> done copying the input to the output.
>
> Best regards,
> Marcus
>
> On 30.12.21 12:32, Cyrille Morin wrote:
>> Hi Marcin,
>> In this graph, the Time sink waits for chunks of 100 samples to display at a time.
>> Since the Throttle is set to forward 1000 samples per second, it should be able to
>> update up to 10 times per second.
>>
>> Keep in mind that this is an estimate since the Throttle block does not enforce its
>> timing exactly. It depends on the size of sample blocks it operates on.
>> So it could be possible that the scheduler gives it a chunk of 1000 samples at a time.
>> In this case, it would forward it whole, and the Time sink would only display the 100
>> samples out of these 1000.
>> If that repeats, you would only get 1 update per second.
>>
>> Hope this makes sense,
>> Cyrille
>>
>>
>> Le 30 décembre 2021 10:38:06 GMT+01:00, "Marcin Puchlik via GNU Radio, the Free &
>> Open-Source Toolkit for Software Radio" <discuss-gnuradio@gnu.org> a écrit :
>>
>>     Hi Marcus,
>>     Thanks for your answer. Please, check out this flowgraph.
>>     Shouldn't the Time Sink update its graph content every second in this configuration?
>>
>>     image.png
>>     https://gist.github.com/marcinsztajn/224ced2e1b3921aa97ef28978c1b8426
>>     <https://gist.github.com/marcinsztajn/224ced2e1b3921aa97ef28978c1b8426>
>>     BR,
>>     Marcin
>>
>>
>>     śr., 29 gru 2021 o 19:27 Marcus Müller <mmueller@gnuradio.org
>>     <mailto:mmueller@gnuradio.org>> napisał(a):
>>
>>         Hi Marcin,
>>
>>         only if there's no other component that limits the speed of processing. For
>>         example, if
>>         the samples come from an SDR, than that has a sampling rate, so there's only so
>> many
>>         samples per second that can reach your sink.
>>
>>           > I noticed that when I am using
>>           > throttle block along with QT GUI Time Sink the update period is not working
>>         properly (I
>>           > have to wait much longer to see the updated graph).
>>
>>         That only happens when the number of samples reaching the sink isn't sufficient to
>>         get one
>>         full vector of samples per update period.
>>
>>         Best regards,
>>         Marcus
>>
>>
>>