I did a "reply all" which may be sending this to accounts where it shouldn't go.
Please accept my apologies if that is so.

On 3/5/2019 1:27 AM, Müller, Marcus (CEL) wrote:
GNU Radio has tutorials on how to write your own blocks, both for
I have found some of those.    But for some (stupid??) reason I linked in long after the introductory material in your links.  I will "start at the start" and see how that works.

How you communicate with your "app" depends on what that is – is it a
separate process continously running, can it be a thread in another
process, or could one understand it as library?

Mine will be a continuously running process.

Generally, GNU Radio was (is) meant to be used as library that you can
use from within your program; 
I sort of had that feeling but I had not stumbled on the right links to tell me how to do that. 
It looks like you have provided those links.
One reason I came to this list is because I was having problems running GRC on my RPi.  I was concerned the RPi didn't have enough power for what I wanted so I was looking for a more direct way then going through GNURadio.

With what you, Sam, and Dale provided I should be in good shape.....after I digest it.

Thanks a bunch,
Pete