Revolution and GPS receivers

Jeffrey Reynolds jeff at siphonophore.com
Mon Jan 24 12:14:46 EST 2005


Ben,

I looked in to this last year. most GPSs use one of a handful of data 
standards (marine units generally use the NMEA standard) that encodes 
the data in a rather strange format. You can buy the standard to decode 
the data or you might also try just putting the output of a gps unit 
(usually 422 serial, but now also usb) into a serial analyzer or a 
terminal program to see if you can figure the data format out yourself. 
I have done this with other sorts of equipment and had good luck. As 
long as they dont actually encrypt the data you can usually pluck it 
out once you are grabbing good data chunks (another fun thing to noodle 
out). This is made easier since you will know exactly what data you are 
looking for (ie the lat lon data on the readout of the gps unit).

i think the data stream will also probably have gmt time of the reading 
and might also have machine specific stuff like course, ground speed, 
etc.

if you google nmea gps standard you will find some interesting info out 
there and some rev files to checkout!

cheers,

jeff

Jeffrey Reynolds
6620 Michaels Dr
Bethesda, MD  20817
301.469.8562
jeff at siphonophore.com

On Jan 24, 2005, at 6:26 AM, use-revolution-request at lists.runrev.com 
wrote:

> Has anyone any experience in linking Rev - on any platform - to a GPS
> reciever, so that it can either poll for coordinates, or receive an 
> update
> of them?
>
> We've just had an enquiry, which we need to move fast on, and I'd 
> really
> appreciate a chat with anyone who's been there before, any tips on kit 
> that
> works/doesn't work, etc.
>
> TIA,



More information about the Use-livecode mailing list