[OSGeo-Discuss] Mobile GPS data collection...

[Mateusz Loskot]

Hi Tyler, All,

Tyler Mitchell wrote:
> I've also done some Pocket PC (windows) based mobile computing 
> applications a few years ago.  This was on the IPAQ (before HP took
> over Compaq) and was a forestry field data collection from surveys of
> waste left over after logging.  We sold a few copies of it.
> 
> The weakest link was the database connectivity (and some general 
> annoyances with the Embedded VB environment).

Yes,eVB environment is not very powerful, but 2-3 y years ago it was the
only simple way to develop form-based apps. Another but not simple was
to use C/C+ with MFC or Windows CE API.

Today, Windows CE platforms are equipped with .NET Framework components
so you can write in VB.NET or C#, but IMHO such solution is not
portable, though the time to market is short.

I still prefer to use C/C++ as these languages
provide very nice portability.

> I ended up sync'ing with an Access db on the client PC through ODBC.
> It worked pretty well, but had these weak links that were not the
> easiest for new users to handle. It was certainly not a cross
> platform or flexible solution but filled the gap.

Funny thing is that Microsoft dropped Pocket Access development and
support quite fast. They sold it to some thirdparty entity.

Now, MS forces users to move to SQL Server Mobile Edition.

> Also, the platform was very slow.  I found populating drop-down lists
>  with more than a few values was slow. This was on the oldest model, 
> 266Mhz processor though :)  Anyway, all that just introduce a bit of 
> what I've done.

But I'm sure it was innovative solution that time.

> I think that having a cross platform solution is ideal, but I'm
> thinking it's going to be tough due to the hardware and PC sync'ing
> issues.  It seems there are some solutions out there that allow
> sync'ing with the Microsoft ActiveSync using an open source protocol
> (I forget the name).


Do you have SyncCE in mind?
http://synce.sourceforge.net

> There also appear to be some issues with PDA->USB->Networking with 
> windows host PCs due to drivers.  I'm curious if anyone has worked 
> through that.  It'd be ideal to avoid the 'sync' problem and get 
> straight into tcp/ip connectivity to databases or via rsync.
> 
> Any thoughts on this?  Others have similar issues?

In almost all my applications for Windows CE I used SQLite database.
SQLite is a C library so it was quite simple to port it.
Here is the port website, by Nuno Lucas
http://sourceforge.net/projects/sqlite-wince

Next, we did not used synchronization support built-in to the
ActiveSync. Instead, we created our own applications for PC or PDA that
does the synchronization work.
Synchronization was based on a patch file transfer.

I'm not sure if there is any stream based transport layer available.
But it should be possible to develope one if needed because Windows CE
platform provides TCP and Bluetooth stacks, in quite good shape.

Note, I've not mentioned Linux on PDA here because the situation is much
simplier with Linux. Many libraries and protocols are available, so
there should be not much problems to create well-working synchronization
layer.

Best regards
-- 
Mateusz Loskot
http://mateusz.loskot.net