Getting time each time power squelch is on

GNU Radio
1

Hello,

I have a Python handcoded block in which I want every time that power
squelch is triggered, grab the actual time and then use that filename
to write a wav file with a decoded stream.

What would be a good approach? I tried using variables but I see they
don’t update at runtime and I am not sure if you are able to change
the wav sink name on runtime and just expect it to work or if it
neccesary to do something else there.

Thanks.

2

Hi Luis,

I am pretty certain there is a block in mainline GR to do this with
tagging. Burst tagger maybe? The tags define the burst boundaries and
a
timestamp is recorded as well.

3

Hi Dan,

Thanks for the response, but it seems like burst tagger would not work
in this case because I am working with audio. What I want is when
power squelch is triggered demod a NFM signal and then save it to a
wav file with the time power squelch was triggered.

Thanks

2015-01-02 16:12 GMT-07:00 Dan CaJacob [email protected]:

4

On Sat, Jan 3, 2015 at 8:39 PM, Luis C. [email protected]
wrote:

Hi Dan,

Thanks for the response, but it seems like burst tagger would not work
in this case because I am working with audio. What I want is when
power squelch is triggered demod a NFM signal and then save it to a
wav file with the time power squelch was triggered.

You can try keeping power squelch’s gate to false (so that you will get
zero samples) and then use it as a trigger for “burst_tagger” after
doing
some math manipulations. This along with a “tagged_file_sink” should
work.

Please look into “gnuradio/examples/tags” for examples.

Sreeraj

5

Hello sreeraj,

I am checking those examples, thanks. Can you elaborate with what you
mean with math manipulations?? Even if I am using tagged_file_sink can
I interpret what is generated as if they were audio wav files?

Thank you.

2015-01-04 4:43 GMT-07:00 sreeraj r [email protected]:

6

Hi, sreeraj,

I figured out what you meant by the math manipulations. Thanks

I based on the example of the uhd energy detector.py for modifying the
output of the power squelch to use it as a trigger on burst tagger.

I see that if I put on audacity 32bit float it’s going to interpret
the file created by the tagged file sink right.

Thanks all of you :slight_smile:

2015-01-04 16:03 GMT-07:00 Luis C. [email protected]: