Re: Transmitting a waveform, and recording input, at an adjustable rep rate

Interesting, thanks, I'll check that out. 

And no, I don't need precise timing control. 

If I do have to do this with Python I might copy the data counting example in the Python Block wiki and connect the message output to the Message To Variable block which could be used to set the state of the recording-Boolean used in the previously mentioned example design. 

On Mon, Apr 29, 2024, 3:13 PM Paul Atreides <maud.dib1984@gmail.com> wrote:

You might have luck modifying this tutorial. 

Understanding XMLRPC Blocks wiki.gnuradio.org

This gives you the ability to change parameters via a separate python script where simple logic may be easier to implement. Not precise timing, but simple. 

<end transmission>

On Apr 29, 2024, at 14:16, Jameson Collins <jameson.collins@gmail.com> wrote:



I'm trying to use GNU Radio to build a test/measurement rig.

At a user-defined interval I want to perform two actions:

 1) Transmit an FM sweep with user definable properties like frequency

 2) And record to a file for a fixed duration.

For the transmitter I was able to adapt the demo case for the lambda function found here: https://wiki.gnuradio.org/index.php/PDU_Lambda.  This seems to work great.

For the recording feature I started with  the example "Pushbutton IQ Recorder with descriptive filenames" (https://wiki.gnuradio.org/index.php?title=Pushbutton_IQ_Recorder_with_descriptive_filenames).  This works by creating a new file, and recording, whenever a user presses and holds a button.  That button sets a variable to true which enables the recording.

But, short of using custom python blocks, I can't figure out a way to trigger the recording at the same time I perform the transmit and I can't figure out a way to stop the recording automatically after a fixed amount of time / samples.