Hi Yugal,
gr-ax25 was just updated this month to start supporting the
development version of GR 3.9 and if you look one commit back it is
is compatible with 3.7, so it does look like it's skipping 3.8.
Still, it's a valuable reference for you as you look to create your
own implementation.
I'd suggest starting by making a transmitter first and testing it by
receiving using existing software. Page 21 onwards here seems to
have a good description of the modulator and demodulator.
https://matheo.uliege.be/bitstream/2268.2/6751/1/OUFTI2-COMM-Piron-2019.pdf
I'm excited to see you implement this. It'd be great to see more
support for the 9600 baud AX25 mode that is used for APRS. It may
not be as good of performance as more modern modes, but there's a
bunch of hardware that supports it.
If you're interested in APRS specifically, by far the best reference
I know of is
W6KWF Kenneth Finnegan's
masters thesis on the protocol.
https://digitalcommons.calpoly.edu/theses/1341/
Cheers,
Derek
MW0LNA
On 12/08/2020 05:29, Yugal Joshi wrote:
Hello Jeff
Thanks for replying
From what I learned in last two days in GNU
Radio, it looks like gr-25 is an OOT module.
gr-25 works with GR 3.9 and pybinds and I am
using GR 3.8.1.0.
Also I want to implement G3RUH 2FSK AX25
using the core modules of GRC or programming new OOTs so
that I can improve my learning curve.
Any help would be appreciated from the
community.
Thanks and Regards
Yugal Joshi
Hello all
I am new to the GNU Radio community.
I am starting an effort to implement a
receiver using GNU Radio for the amateur radio
whose transmitter operates in G3RUH mode with
2-FSK modulation and AX25 data format.
I designed the project to learn GNU Radio as
well as to contribute something to the SmallSat
Community of my institution Indian Institute of
Space Science and Technology (IIST).
Is anyone else working on the same
configurations ?
Anyone who can guide me through the procedural
steps I should take to design this receiver(G3RUH
mode with 2-FSK and AX25 data format)?
As a background information :
The AX.25 protocol is a standard for encoding the
data that includes a message header,station
callsign, destination callsign, message and a
simple CRC-16.
The system is widely used for position reporting
of the amateur stations
Looking for a directive
path to move ahead and a positive response.
Thanks and Regards
--
Yugal Joshi
B. Tech. Electronics and Communication
Engineering
Indian Institute of Space Science and
Technology (IIST)
Thiruvananthapuram
Kerala
India - 695547