Re: Problem with GFSK Mod and Demod example from wiki

[Jeff S]

I probably should have added a modification to your flow graph using an Unpack 
block that would allow your flow graph to work and to show what I was 
describing.

Jeff

________________________________________
From: Discuss-gnuradio <discuss-gnuradio-bounces+e070832=hotmail.com@gnu.org> 
on behalf of Jeff S <e070832@hotmail.com>
Sent: Monday, August 23, 2021 6:21 AM
To: Nikoloz Glonti; discuss-gnuradio@gnu.org
Subject: Re: Problem with GFSK Mod and Demod example from wiki

Nicko,

It doesn't look to me like the Time Sink is looking at the same type of data.  
Symbols (full 8-bit bytes) are going into the GFSK Mod.  What is coming out of 
the GFSK Demod appears to be 8-sample representations of the input byte.  You 
can see from the first tag on the Signal 1 that there are seven zeros followed 
by a 1, which represents your first input byte of 0x01.  If you look at the 
rest of the samples in 8-bit chunks, you'll see your vector represented (0x01, 
0x00, ...).  I believe the flow graph will eventually stall since there is 8x 
more data going into port 0 as there is port 1.

As for your original question about the wiki, it looks like it may be 
referencing a later version than what I have (I am using v3.8) because there is 
an "Unpack" configuration option in the GFSK Mod that I don't have, and it may 
be the same for you (I didn't see you post version info of what you are using). 
 I am not sure at this point if that is what is causing the wiki example to 
work, while your example does not.

Hope my inarticulate description helps some.
Jeff



________________________________________
From: Discuss-gnuradio <discuss-gnuradio-bounces+e070832=hotmail.com@gnu.org> 
on behalf of Nikoloz Glonti <ng91@glonti.com>
Sent: Friday, August 20, 2021 4:01 PM
To: discuss-gnuradio@gnu.org
Subject: Problem with GFSK Mod and Demod example from wiki

Hello everybody,

I want to do some simple test of GFSK modulator and demodulator. I used
an example from wiki - https://wiki.gnuradio.org/index.php/GFSK_Demod .
I copied flowgraph, but my Time sink shows me only signal on input of
modulator - output signal is really weird - some peaks...
Why I can't get the same results as shown on wiki?


Niko

Screenshot from 2021-08-23 06-40-06.png
Description: Screenshot from 2021-08-23 06-40-06.png