Hi Al, If you need testers, please contact me. I have several gta02v5 available and can do tests in Germany Munich.
thanks Kai 2008/7/7 Al Johnson <[EMAIL PROTECTED]>: > I'm not saying there isn't an antenna issue, but that we may be able to > mitigate the effects on startup time. > > On Monday 07 July 2008, Kai Römer wrote: >> 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 > [email protected] > http://lists.openmoko.org/mailman/listinfo/community > _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
