On Tue, 28 Oct 2008 01:36:36 +0530, Gora Mohanty <[EMAIL PROTECTED]> wrote: > On Mon, 27 Oct 2008 20:56:54 +0100 > David Garabana Barro <[EMAIL PROTECTED]> wrote: > [...] >> I allways though Freerunner had AGPS. That's what wiki says: >> >> http://wiki.openmoko.org/wiki/Neo_FreeRunner_Hardware#AGPS >> >> Isn't it true? > [...] > > Yes, I believe that it does have AGPS capabilities. But AGPS > needs someone sending out the AGPS data. I don't know that > that is being done with OpenMoko. > > Regards, > Gora
http://wiki.openmoko.org/wiki/AGPS http://svn.openmoko.org/developers/matt_hsu/agps-online/ aGPS works nicely but isn't fully utilized ATM in most cases. You can register for a free account at u-blox.com (chipset manufacturer for the GPS in the FR - send empty email to agps-account at u-blox.com and get password back) and use a tool called 'agps-onlinec' (at the SVN above) in the instance I tested, and feed it some relevant data: agps-onlinec -c full -u [EMAIL PROTECTED] -k Fvhcv -la 35.22 -lo -79.46 -al 250 -p 100.00 & the -u is email address used to register above, '-k' is the password provided in the reply email, '-la' and '-lo' and '-al' are current lat and long and altitude, and the '-p' is precision in kilometers. If you have a very accurate position already (eg you're at home and know precisely what the GPS /should/ read) you can get a fix in a very short time with "-p 1", provided the location data prefed to agps-onlinec and the current time (system clock) are accurate enough. (clock doesn't need to be second-precise, but if it's off several hours or more then you've got problems) On warm restart of the GPS it retains this data within the GPS, on cold restart it is lost and must be resupplied from outside or it takes significantly longer again to get a fix. Frameworkd (FSO) apparently stores almanac data automatically and feeds it back into the GPS on startup, so if you're within a couple hours of previous GPS usage (I presume) you get a faster fix. Ideal in my mind would be to check cell tower ID and/or wifi AP MAC against previously-cached records and feed the location data from those records (with appropriate precision data, perhaps 10km for cell-tower?) into agps-onlinec and let it retrieve data via GPRS from the assistance server. (even better would be a local service ON the FR that retrieves the full 2-week dataset and serves up the appropriate data on demand, but I'm not even sure if that can be done without careful dissection of both protocols - the long-term data isn't supported by the GPS inside the FR) j _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
