Hi, thanks for your work, but it didn't work for me. I used your spreadsheet to calculate the values. Is there something I can do wrong? It sets the time, but I still don't get a fix.
$posx = 3784209.3; $posy = 901525.8; $posz = 5037577.6; Are my values for Berlin/Germany (52.516667, 13.416667, h left 0) Strange thing is, it works great with an external antenna. I usually get a fix in less than 40 seconds, the freerunner even stays connected to those satellites when I unplug the antenna and holds the fix as long as it sees some sky. Al Johnson wrote: > On Monday 07 July 2008, Kai Römer wrote: > >> Hi Al, >> If you need testers, please contact me. I have several gta02v5 >> available and can do tests in Germany Munich. >> > > 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 > [email protected] > http://lists.openmoko.org/mailman/listinfo/community > _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
