Looking for working "hello world" example for "function probe" with "signal probe"

#1

Hi,

I’m looking for a working “hello world” example for using
“function probe” with “signal probe” in gnuradio companion.

I can’t get it to work with the existing documentation found.

Thanks for any input.

Mario

#2

On Wed, Mar 28, 2012 at 6:04 AM, mario behn removed_email_address@domain.invalid
wrote:

Hi,

I’m looking for a working “hello world” example for using
“function probe” with “signal probe” in gnuradio companion.

I can’t get it to work with the existing documentation found.

Thanks for any input.

Mario

In the “Function Probe” block you want:
Block ID: whatever the ID of your “Probe Signal” block is.
Function Name: level

#3

Actually what should go into the value field of Function Probe?

#4

Hello:
I was trying to use the function probe with a custom blocks and it does
not update its value. I set the block ID correctly and the function
name. The flow graph executes normally but no change occurs in the
function probe value. I am using gnuradio 3.5.1. if anyone could help me
will be great
thanks in advance
Damian

#5

On Wed, Mar 28, 2012 at 12:46 PM, mario behn removed_email_address@domain.invalid
wrote:

Actually what should go into the value field of Function Probe?

Hopefully the attached grc file will clarify things

Value can be anything you want, it is used as the initial value,
overridden when the function probe is called at poll rate

Jason

#6

Just wanted to post this in the event someone else is looking into this issue:

When GRC creates top_block.py it will often define the probe call (_probe_probe) before instantiating the probe signal block it is referencing, causing python to throw an error.

This can be fixed in top_block by moving the probe signal block declaration above the probe call definition.

I don’t know of any other blocks with this (bad) behavior, but the GRC team should enforce placing probe call definitions at the end of the blocks section of a flowgraph.