On Mon, Mar 31, 2008 at 7:45 PM, Andrew Daviel <advax at triumf.ca> wrote: > On Mon, 31 Mar 2008, Frederic Crozat wrote: > > > Once you get the almanac downloaded, fix time can be shorter (5 > > minutes to 10 minutes in bad conditions). And if you got a fix in the > > Any idea where the almanac is stored ? In the GPS chip itself ? Does it > survive power-down or dead battery ? I gather it's a Texas device > (GPS5300) with not a lot of info on the Web (contact TI if you're a > cellphone maker wanting millions of the things, hobbyists need not > apply). The 2-page teaser suggests that it communicates over a serial > bus, maybe native NMEA0183. There has been a lot of discussions on Internet Tablet forum. It is probably stored in /var/lib/gps/nvd_data but nobody has been able to decode the file format. > > Also remember GPS antenna is located under the zoom in/out button, so > > try to not hold your n810 with your hand over them (at least for > > initial GPS fix). > > I had assumed it was the little plastic square just above the camera, so > that the best orientation was screen side upwards with a good view of the > sky. Once I had a fix, then I could put it in my pocket riding a bike. No, the plastic square is the light sensor ;) But I concur with your findings about keeping a fix once you get it. > I'm not sure Maemo Mapper really has more information available. > As far as I can figure, gpsd translates NMEA from the device to a > generic format and makes it available to multiple clients on > localhost:2947. > The NMEA includes $GPGSV GPS Satellites in View. You can see this if you > connect to the socket with netcat and give an "r" (raw) command, or > "q" or "y". > In Nokia Map the "gps view" shows signal levels and satellite position > graphically, I presume derived from this information. Yes, but accessing those "detailed" informations from Maps is preventing use of the application, unlike Maemo-Mapper (you can even bind "show GPS details" to a hardware key). And even Maemo-Mapper "establishing GPS fix" progress bar is a good indicator for fix progression. > - I'm curious. What time-to-first-fix are people experiencing ? Between 5 to 10 minutes usually (in Paris). After a fix, I've done more tests in disabling GPS and enabling it back and was sometime able to get fix from 30s to 2 minutes (inside a bus moving..) > (I guess I should quantify my own experience..) Install gps-clockd, it record TTF, as well as syncing clock to GPS clock -- Frederic Crozat
