[TI-H] Re: Connecting a gps tracking mouse to the Ti-89
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[TI-H] Re: Connecting a gps tracking mouse to the Ti-89
thx for your answers so far!
As far as I could figure out the gps mouse will send its data asynchronously
at 4800 bauds.
The connection parameters are: 4800, n, 8, 1 stop bit (what does n,8 mean?).
Is this the way PC link programms transfer data to the ti-89 (I use the grey
Ti-graph link cable) ? Is 4800 bauds slow enough for the ti-89 to receive
without a convertion to synchronous transfer (I wont care if some packages
get lost !)?
Once the ti-89 will receive the data, the package interpretation should be
easy, cause the gps-mouse will send simple character streams in the form
$GPGGA,144931,5054.9257,N,00659.2189,E,0,00,,,M,,M,,
where $GP... indicates the beginning of a new data package.
----- Original Message -----
From: "Olle Hedman" <alh@home.se>
To: <ti-hardware@lists.ticalc.org>
Sent: Friday, January 31, 2003 7:35 AM
Subject: [TI-H] Re: Connecting a gps tracking mouse to the Ti-89
> Tristan Schaap wrote:
>
> > Ofcourse the connection speed has to be constant, first of all, a
> > processor needs a set frequency, this is usually done using either an
> > internal oscillator, or external crystal or RC circuit. Also, the
> > speed you send at automatticly becomes the speed the TI receives at.
> > (There is ofcourse a certain limit, 9600 Baud or something). Read the
> > information about the protocols on ti-calc.org.
>
> The protocol for the TI link, does not define any speed...
> It is syncronous, and goes as fast as the involved calcs can handle, or
> at 9600 if you use the grey linkcable, but this is because of the design
> of the cable, not the calc. Different calcs can go different speeds. the
> ti89 I think handles up to about 50Kbit/s
> The calc is driven by a RC-circuit, and this is temperature sensitive,
> and battery dependant. Thus, the speed of the calc is not 100%
> predictable, making it a pain do do asyncronous communication.
> But at low speeds it is probably possible. Or you have to have some
> circuitry in between with real crystal that converts asyncronous data to
> calc syncronous.
>
> --Olle
>
>
>
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