British National Grid.

dynamite · Posted: Thu Jul 22, 2004 4:35 pm Post subject:

I must apologise for having left this one to rot for so long... I've simply not had the time to progress it. The basic code exists and works, but it needs a user interface on the front of it and that just takes forever to put together...

Keep hanging on - something will pop out one of these days (or weeks...)

- Niels
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nej · Posted: Fri Jul 23, 2004 11:18 am Post subject:

Must've missed this thread before!

I did look at doing this but converting lat/long to OS Grid etc is really really hard!! I did find a link somewhere that attempted to explain the algorithm but it's incredibly complicated and I gave up as it was well beyond my mathematic capabilities!

There is a company that does a product called GPSTools (I think it is franson.biz or something like that) which I think is an ActiveX control that may help do it.

andyblissett · Regular Visitor Joined: Jun 20, 2004 Posts: 65

Post me the algorithm. Im a mathematician, so I can convert it into structured english for you if you want.

Andy

nej · Posted: Fri Jul 23, 2004 3:57 pm Post subject:

Thanks for the offer Andy but it looks like Niels has it under control!

barryd · Posted: Fri Jul 23, 2004 6:28 pm Post subject:

The Ordnance Survey provide algorithms and sample code for converting in both directions on their web site.

Barry

palmley · Occasional Visitor Joined: Jul 24, 2004 Posts: 1

I don't know if this Excel spreadsheet would be of any good to you, but I've used it in the past to do converstions and found it very useful

www.bangor.ac.uk/is/iss025/osgb.xls

fleng · Posted: Mon Jul 26, 2004 4:32 pm Post subject:

This link might help.

http://www.streetmap.co.uk/streetmap.dll?GridConvert&type=postcode&name=MK76AA

shanks · Last edited by shanks on Fri Dec 14, 2007 5:12 pm; edited 1 time in total

I've been working on this very topic myself and fed up with the lack of free conversion utilities for my PocketPC wrote one myself using eVC based on the Ordnance Survey's published algorithms. It converts WGS84 lat/long (as reported by GPS units) to and from OS grid references. You can obtain the program here at the moment:

http://www.craporola.com/OSGridConv.exe

Note it'll only work on ARM PocketPC 2003 (eg. ipaq 2210).

I've recently discovered how to read a GPS stream and so will be soon releasing a program to show your grid ref in real time, and perhaps (I hope) even plot position on a raster map.

Let me know if this is useful or you'd like further info.

dr. matt

dmac

nej · Posted: Wed Jul 28, 2004 8:55 am Post subject:

Excellent - all it needed was someone with brains!

What would be useful is if you could enter a grid ref, and your program converts to lat/long. Even more useful would be if it kicked off TomTom to start it navigating to that location.

MikeyH · Posted: Mon Aug 02, 2004 11:15 pm Post subject:

Well what can I say, back in March when I posted the origional thread i thought id get nowhere with the idea of displaying BNG on my Tom Tom.

The only problem I have at the mo, is im using TTN3, and I believe Tom Tom jacket the GPS stream, which stops me from using other software with it.

Would that happen here?

Mike.
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nej · Posted: Tue Aug 03, 2004 10:52 am Post subject:

You can get the current position using the TomTom SDK. That might help.

barryd · Posted: Wed Aug 04, 2004 12:34 am Post subject: OSGB WGS Convertor

Hi there

I've also been working on a utility to do the conversion (in both directions, several formats), then show it on the TomTom map. Not having the TomTom SDK it's a little Heath Robinson, but it works for me.

I'd be interested in any opinions of it. Particularly whether or not it works on Pocket PC 2002, which I can't test.

Info and download at: http://www.freenetpages.co.uk/hp/barrydavies/OSGBWGS.htm.
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Barry Davies

DaveCo · Occasional Visitor Joined: Aug 25, 2004 Posts: 1

The ability to convert BNG to long lat for TomTom would be useful but can this be extended to ING (Irish National grid?) I can supply an algorithm if necessary but I need a developer who can put this together in a tight timescale ready for rollout to a client.

I am also looking to include a heading indicator to be incorporated, I have contacted a couple of people on this thread already but if someone is interested in taking on this development please contact me.

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