1200 baud ax.25 can easily be implemented in hardware or software today. Hence its popularity. And there are radios with the protocol and arguably the most popular application (APRS) implemented directly. Kenwood was the first to push a radio with an AX.25 terminal node controller embedded, with specific APRS hooks.
Gerry On Wed, Aug 12, 2020 at 12:38 PM Adrian Musceac <kanto...@gmail.com> wrote: > Hi Derek, > > Isn't APRS 1200 baud though? 9600 baud packet is quite uncommon nowadays > here, historically it was used for BBS access. > I'm also interested in this APRS transceiver. > > Best, > Adrian > > On August 12, 2020 12:12:09 PM UTC, Derek Kozel <de...@bitstovolts.com> > wrote: >> >> 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 >> >> >> On Wed, 12 Aug 2020, 4:45 am Jeff Long, <willco...@gmail.com> wrote: >> >>> Have you already take a look at this? >>> https://github.com/dl1ksv/gr-ax25 >>> >>> On Tue, Aug 11, 2020 at 4:13 PM Yugal Joshi <yugaljoshi2...@gmail.com> >>> wrote: >>> >>>> 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 >>>> >>> >> -- Gerry Creager NSSL/CIMMS (C) 979.229.5301 <--- NOTE THAT MY OFFICE NUMBER HAS CHANGED ++++++++++++++++++++++ *The way to get started is to quit talking and begin doing.* * Walt Disney*
