On Mon, 7 Jul 2008 15:37:08 +0100 Al Johnson <[EMAIL PROTECTED]> 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 ;-) _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community