[arm-allstar] CM119A GPIO

[Doug Crompton]

Typically 1200 baud  VHF/UHF and 300 baud HF.  I did some 2400 baud with
speaker/mic inputs back in the 90's but anything above that would require a
special mod/demod and going straight to the discriminator in the radio.
There was some 56K stuff on UHF and above in the day but I doubt there is
much if any of that going on now. I remember the GRAPES group was doing
that. It is a shame because with all the hoopla about mesh and 2.4/5Ghz
long range it is just not practical for most hams and in most areas.
Terrain and obstructions limit it severely.  We have 10 Mhz from 420 to 430
that is rarely used any more and setting up high speed packet there would
be a nice alternative where mesh just does not work reliably.


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*

On Thu, Dec 6, 2018 at 4:33 AM "Michael Durkin via ARM-allstar" <
arm-allstar at hamvoip.org> wrote:

> What's the normal baud rate for packet radio ax25 that's been used for
> years? ... I have used the cm108 for packet radio (DireWolf modem) and
> unmodified with my SDR ... UHFSDR.
>
>
>
> On Wed, Dec 5, 2018, 9:55 PM "Doug Crompton via ARM-allstar" <
> arm-allstar at hamvoip.org wrote:
>
> > I think you are talking about two different things. The CM108/119 is an
> A/D
> > - D/A which supports up to about 18Khz audio. The way this is used and
> down
> > sampled in Allstar the maximum audio frequency is about 3.6Khz which can
> > pass many of the lower speed digital modes. In fact we have tested it and
> > there are digital nets using it as connected Allstar. I say lower speed
> > because none even approach 1200 baud. Whether you could accurately decode
> > 9600 baud in a wide open audio bandwidth situation reliably is kind of
> > doubtful. It certainly would not work in an unmodified radio. The CMxxx
> > also has Digital I/O - the 108 has 4 bits and the 119 has 8 bits. These
> > bits are not designed to pass high speed data nor is there a way to
> create
> > a specific baud rate and ensure it is accurate. If you want to send or
> > receive serial data there are several choices. One would be the Pi, it
> has
> > bits designed for this and another is a serial to USB adapter. They are
> > cheap and just work.
> >
> >
> > *73 Doug*
> >
> > *WA3DSP*
> >
> > *http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*
> >
> > On Thu, Dec 6, 2018 at 12:41 AM "Steve L via ARM-allstar" <
> > arm-allstar at hamvoip.org> wrote:
> >
> > > Marty,
> > >
> > > I know Direwolf is a "soundcard" based AX.25 modem that supports 9600
> > > baud and the cm108/119 chipset.
> > >
> > > https://github.com/wb2osz/direwolf
> > >
> > >
> > > On Wed, Dec 5, 2018 at 11:09 AM "Marty via ARM-allstar"
> > > <arm-allstar at hamvoip.org> wrote:
> > > >
> > > > I'm working on another project for Allstar Link. My question about
> the
> > > CM119A GPIO can handle(tx/rx) 9600baud? I'm working on controlling a
> > radio
> > > module.
> > > >
> > > > 73,
> > > > Marty KD4HLV
> > > > ALLSTAR 28523
> > > > _______________________________________________
> > > >
> > > > ARM-allstar mailing list
> > > > ARM-allstar at hamvoip.org
> > > > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> > > >
> > > > Visit the BBB and RPi2/3 web page - http://hamvoip.org
> > > _______________________________________________
> > >
> > > ARM-allstar mailing list
> > > ARM-allstar at hamvoip.org
> > > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> > >
> > > Visit the BBB and RPi2/3 web page - http://hamvoip.org
> > >
> > _______________________________________________
> >
> > ARM-allstar mailing list
> > ARM-allstar at hamvoip.org
> > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> >
> > Visit the BBB and RPi2/3 web page - http://hamvoip.org
> >
> _______________________________________________
>
> ARM-allstar mailing list
> ARM-allstar at hamvoip.org
> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>
> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>