[arm-allstar] CM119A GPIO

Randy Neals randy at neals.ca
Thu Dec 6 07:10:41 EST 2018


If you needed to generate AFSK modem tones, then yes, with a software modem
the CM119 will make tones and communicate data.
But RS232 digital levels to communicate to a device are like apples and
oranges compared to generating AFSK modem tones.

On Thu, Dec 6, 2018 at 1:33 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
> > > > _______________________________________________
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> >
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