Ant: [Openstreetmap] OpenStreetMap/Freemap and mobile devices?

frank mohr f_mohr at yahoo.de
Wed Jun 1 19:39:37 BST 2005


hi

--- Nick Whitelegg <nick at hogweed.org> schrieb:

> A thought I've had for some time with Freemap, wouldn't it be good if
> OSM maps 
> could be displayed on mobile devices like PDAs or even phones?
> Without a lot 
> of knowledge in this area ATM (but am keen to learn) I'm not sure how
> 
> feasible it would be but the following appear to be true:

sorry what do you mean by ATM (just a guess: "At The Moment" ?
i only know it as abbreviation for "automated teller machine" 
and "Asynchronous Transfer Mode")

> a) the device would need inbuilt GPS;
> 
> b) There would seem to be two ways of implementing this:
> 
> i) Get your current position from the inbuilt GPS, construct an HTTP
> request 
> to the server using, e.g. the cURL library, and get a map back as,
> say, a PNG 
> image.

that would be the easiest way

> ii) Send an XML-RPC request to the server, get the raw data back then
> process 
> the data to draw the map on the mobile device. This is more flexible
> but 
> requires more processing on the device.

I had a demo map program with a London streetmap for my Palm that 
worked rather fast and current PDAs have a better performance than 
my old Palm Vx.

> c) the device would need to make a request to the server every x
> minutes or 
> seconds, or when the position has changed by y metres/feet.

if you use b)ii) you can fetch a larger area and only need to refetch 
the next dataset if you approach the borders of the stored area

> Doubtless there are many practical problems with battery life, etc,
> but it 
> would certainly be something worth investigating. I also gather that
> most 
> mobile devices cannot connect arbitrarily to the internet through 
> user-written software, for security reasons. So (correct me if I'm
> wrong) it 
> would only be possible to do this sort of development under the
> Linux/Qtopia 
> environment at the moment and not under Symbian or Palm environments.

on the palm you can do this 
i'm sometimes (or better rarely) using a mail program on the palm 
that automatically starts the connection (over mobile phone) if i 
fetch new mail.

> If this is feasible it's certainly something I would like to get
> involved in. 
> Are there suitable PDAs out there with GPS ability, or could I get a
> cheap 
> pluggable GPS unit and plug it into an arbitrary PDA?

there are some PDAs with build in GPS receivers (Garmin iQue 3200 with
PalmOS or iQue M5 with WinMobile and some others)

most current PDAs have a CompactFlash slot and there are GPS receivers
for that slot

frank


	
		
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