GPS

[Francesco Cat]

Another thing that might help: If the FR is connected to any network
one should also be able to use IP Locator services like
http://whatismyipaddress.com/ to get another extimation of the
location of FR. They are usually quite accurate.

Would this help?

2008/7/7 Yogiz <yogizz at gmail.com>:
> On Mon, 7 Jul 2008 15:37:08 +0100
> Al Johnson <openmoko at mazikeen.demon.co.uk> wrote:
>
> Thank you for the testing. Keep doing the good work.
> Hopefully this idea can solve the long fix problem.
>>
>> First stab uses the example perl functions from ublox for generating
>> the aid-ini data, replacing their hardcoded x,y,z with values for my
>> location. The copyright notice on the example code says you can't do
>> anything with it without permission so I can't give you the script,
>> but I can tell you how to reproduce it ;-)
>>
>> Get the AssistNow online client application note from:
>> http://people.openmoko.org/matt_hsu/ImplementationAssistNowServerAndClient(GPS.G4-SW-05017-C).pdf
>>
>> Create a new script aid-ini.pl and start with:
>>
>> #!/usr/bin/perl
>> print(clientdata_prepare());
>>
>> Go to section B - Sample Server implementation and append subroutines
>> clientdata_prepare and ubx_checksum to aid-ini.pl
>>
>> You need to replace the $posx, $posy and $posz values in
>> clientdata_prepare with some that match your location. These are ECEF
>> coordinated in m. There's an explanation of the calculation method in:
>> http://www.u-blox.com/customersupport/docs/GPS.G1-X-00006.pdf
>>
>> Alternatively you can use the attached spreadsheet if it survives the
>> list. Just replace the lat and lon with values for your location.
>>
>> You probably want to change the time accuracy to reflect the accuracy
>> of the Freerunner clock, and possibly the accuracy of your location
>> estimate.
>>
>> Now copy the script to somewhere suitable on the Freerunner and make
>> it executable. I'm using /usr/local/bin. You need to install perl if
>> you don't have it already:
>> opkg install perl
>>
>> Switch on the GPS then run the script:
>> /usr/local/bin/aid-ini.pl > /dev/ttySAC1
>>
>> If you cat /dev/ttySAC1 you should be able to see it using the
>> current time according to your Freerunner. TangoGPS makes it easier
>> to see what it's doing. In the only test I've managed so far it got a
>> fix with a poor view of the sky, while my Garmin Geko was still
>> struggling to see 3 sats. It wasn't quick, but it was better than the
>> Garmin. It would be interesting if you could try 2 units side by
>> side, one with aid-ini and one without, to see if it really makes a
>> difference or if I was just lucky. I'll try to get some more testing
>> in, but the weather isn't good here, and I don't want to get my new
>> toy wet ;-)
>
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