[FSO] Speed gps time to firxt fix up?
Quakeman1 at gmx.net
Sat Jan 3 14:23:25 CET 2009
I did nothing special.
I only deinstalled gpsd and installed fso-gpsd. Some time ago fso-gpsd
wasn't working good at all. But a few weeks ago i tried again to replace
gpsd with fso-gpsd and since than it works ok.
Interesting is that with fso-gpsd the gps chip is activated as soon as a
connection to the fso-gpsd port is opened. And it is deactivated when
the last connection closes. This feature has pros and cons but at the
moment i like it. :)
> what did you made to get GPS working in general ?
> See my post about GPS ...
> Fox Mulder wrote:
>> Since a few weeks i'm using fso-gpsd without any big problems so far.
>> The only problem is that the TTFF (time to first fix) is always >1
>> minute and sometimes it needs quite a lot of time. The only solution for
>> me to be sure to get a fix within <30 sec is to use the agps tool which
>> downloads the almanac and ephemeris from ublox for my region.
>> The problem is, that the gps chip doesn't have any internal memory why
>> it needs to download all relevant gps data every time it is powered up.
>> So i thought if it is possible to save the relevant gps data before
>> shutting down the gps which can be done by fso-gpsd or kernel
>> automatically. Than after starting the gps fso-gpsd/kernel feeds back
>> the data to speed up the TTFF. This would be the same way most gps
>> receivers work.
>> Maybe this is already implemented somewhere but i don't think so because
>> the TTFF without agps is always quite slow.
>> Openmoko community mailing list
>> community at lists.openmoko.org
More information about the community