Hi
We use GPS recievers in our data loggers....the 1Hz signal they
provide helps lock the loggers as it is more accurate
in the long term than a crystal (though not in the short term
cos of the jitter the military put in)

We paid NZ$300 (about$200US) for a Trimble reciever.

These recievers (and I guess most) also put out an rs232
signal every second of about 20 words, containing stuff like
the hour,minute,second,velocity,and position I think. Basically
your manual will give the details. This can be read by anything
that can read rs232.
The iHz pulse is ttl level, and I'm told the rising edge(but not the
falling) is accurate to 500nS

Hope this helps
Tim

On Tue, 9 Dec 1997, John Shreffler wrote:

> Try http://www.ashtech.com  You can get bare boards for $98
>
> -----Original Message-----
> From:   Randie Ohtsji [4555] [SMTP:rohtsji@GLENVAN.GLENAYRE.COM]
> Sent:   Tuesday, December 09, 1997 2:34 PM
> To:     PICLIST@MITVMA.MIT.EDU
> Subject:        gps
>
> Hello,
>
> I am interested in more information on GPS.  Does anyone have any good
> links?
>
> Questions:
>
>         1) Has anyone interfaced a gps receiver with a pic before?
>         2) Source of low-cost gps receivers?
>         3) How accurate are they?
>         4) How do you interpret the data and calculate your location?
>
> Any information would be appreciated!
>
> -Randie
>                                     ________
>    Randie Ohtsji                   / ____/ /__  ____  ____ ___  _________
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>    Glenayre R & D                / /_\ / /  __/ / / / /_/ / /_/ / / /  __/
>    Vancouver, B.C.  CANADA       \____/_/\___/_/ /_/\__,_/\__  /_/  \___/
>    Phone: (604) 293-1611 x4555      ________________________/ /
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>