Hi Al, Sounds really convincing, but how do you explain the constantly fast fix via external antenna then. I really think its an antenna issue.
Also the difference of the GPGSV values support this idea. Tomorrow evening i will ask a specialist to check the antenna signal qualities. Maybe a cable is broken or there is a short circuit on the main board. I ll report about the results. CU Kai 2008/7/6 Al Johnson <[EMAIL PROTECTED]>: > From what I've seen on the wiki the version of the Antares4 on the GTA02 > doesn't have the memory needed to store almanac and ephemeris, last known > position or time. This means that every start is a true cold start, unlike > every other reasonably modern GPS we're comparing it to. It starts up > thinking the time is midnight on 30th November 1999 and seems to need a fair > bit of decent signal to convince it otherwise, contributing to the long > startup time. > > It looks like there is a way around this if you look at the documentation for > the assist. The AID-INI message needn't be supplied by a remote server; we > can generate it locally to provide the sort of data that's stored internally > most of the time. At the very least we have a fair idea of the current time > and date. We should also be able to store location, almanac and ephemeris > when we shut down the GPS, and provide it at the next startup. We can also > have a stab at current location, based perhaps on cell ID or wifi data as > discussed by some of the other threads, or on user input. > > I'll try to patch together something to do this based on the example perl > client and server code, and see how much difference it makes. > > On Friday 04 July 2008, Kai Römer wrote: >> I can affirm this for 6 opemoko devices. i guess its an internal >> antenna issue. as soon as you connect a external antenna to it works >> like a charm. but fur me thats no solution. >> >> TTFF with external antenna (perfect condition): 40 to 60 seconds >> TTFF with internal antenna AGPS (perfect condition): more than 1:20 >> minute but not always. its like gambling. >> >> I guess a miss design of the internal antenna. >> >> CU Kai >> >> 2008/6/23 Peter Kraker <[EMAIL PROTECTED]>: >> > This timings are insane unless you don't even have a valid almanac, which >> > is rare. This doesn't look right. >> > >> > Yorick Matthys pravi: >> > >> > Marcus Bauer said: >> > >> > >> > My experience with the Freerunner is ~12 minutes TTFF (time to first >> > fix) without use of agps and ~4-8 minutes TTFF with agps from >> > agps.u-blox.com using the software from openmoko. >> > >> > The Neo1973 (GTA01) had a TTFF without agps assistance of ~2 min. >> > >> > >> > 12 minutes without AGPS and 4-8min with AGPS?? >> > I hope there was a thunderstorm inside the basement where you tested >> > this... >> > >> > :) >> > >> > Seriously, these just don't seem realistic. >> > Compare them for example with some other devices from 2003: >> > http://www.pocketgpsworld.com/ttffcomparisons.php. >> > Or from ublox: http://www.u-blox.com/technology/assistnow/ (table at the >> > bottom of the page) >> > >> > Surely there must be something wrong with your >> > software/settings/hardware/environment... >> > (or maybe they still have a lot of work to do on the GPS :)) >> > >> > y > > _______________________________________________ > Openmoko community mailing list > community@lists.openmoko.org > http://lists.openmoko.org/mailman/listinfo/community > _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
