Revolution Reading GPS Data

Graham Samuel livfoss at mac.com
Sun Mar 2 15:26:23 EST 2008


This interests me also - I have a simple GPS device (a so-called  
'training' device) which captures trackpoints and waypoints. Its  
current PC software is just that, i.e. it doesn't work on a Mac, and  
more or less the only thing it can do is to create a kml file for use  
by Google Earth. I am not at all sure that it uses the same chipset  
as the mainstream GPS devices (the kind you can pre-programme with a  
route, like Garmin etc), but my main problem in even starting to deal  
with it is the lack of USB capability in Rev. In order to talk to the  
device, I have to have a USB driver of some kind and I absolutely do  
not know where to start. I have tried emailing both the retailer and  
the manufacturer for advice but neither has bothered to reply.

Has anyone got any advice about cracking the USB problem?

TIA

Graham

On Sun, 02 Mar 2008 12:42:43 +0000, Ben Rubinstein  
<benr_mc at cogapp.com> wrote:
>
> On 1/3/08 22:59, R. Hillen wrote:
>> is there anybody who succeeded in reading data from a gps device  
>> into a
>> revolution application?
>>
>> How did you do it? Which device did you use?
>
> Hi Richard,
>
> I did this a couple of years ago in Rev - it was very  
> straightforward.  All
> (er, virtually all) GPS devices speak NMEA, which is widely  
> documented on the
> web.  We worked with a couple of different devices, and the  
> software didn't
> notice any difference (apart from anything else, I think pretty  
> much everyone
> is using the same chipsets).
>
> We did this on Mac and Windows; the only difficulty was locating  
> Mac drivers.
>   All the devices we worked with were serial originally with serial- 
> USB chips
> bolted on; there seemed to be a couple of different ones of these.   
> The other
> way that working on Windows was easier in locating the device  
> automatically -
> just iterated through COM1-10; on the Mac I think we had to set the  
> name of
> the device in the configuration.
>
> The devices just spend a steady stream of data; in the NMEA format  
> this is
> ASCII, line formatted; so I had a handler running on a timer which  
> read data
> from the port and buffered it, and then invoked a handler to see  
> whether there
> were any completed "sentences" to process.
>
> That handler in turn checked whether the position etc information  
> had changed,
> and if so invoked a handler to actually do whatever it was supposed  
> to be.
>
> In theory you can switch the devices into a binary format which  
> should be much
> faster - but we didn't seem to need the speed and I never dared try  
> in case I
> couldn't get it to switch back!
>
> Good luck,
>
> - Ben



                       ----------------------------------------
Graham Samuel / The Living Fossil Co. / UK and France




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