TangoGPS and GPSD
joerg at openmoko.org
Sun Jul 6 19:52:51 CEST 2008
Am So 6. Juli 2008 schrieb Marcus Bauer:
> On Sun, 2008-07-06 at 19:17 +0200, Bernhard Höll wrote:
> > Hi,
> > unfortunately I still get no GPS data. I went for a 25 minute trip on a
> > plain field, so GPS reception should be no prob. .
> My Freerunner needs ~5 minutes before it has the time (tangoGPS displays
> the time of the GPS even if there is no fix) and ~10-15 minutes overall
> before it gets a fix. If I move, even just walking or have the Neo not
> in an upright position, I don't get a fix at all. Clear skyview of 80%
> sky is necessary for my FR too.
Just to add to and confirm this: acquisition (mere download) of efem/alm takes
12min, if not interrupted by walking around etc, and needs a 30dB higher
signal than normal GPS operation.
Placing the FR flat on a table will probably not see a fix at all, due to
orientation of internal GPS-antenna being front long axis.
TTFF can be significantly speed up by supplying time/efem/alm data on startup
of GPS-receiver. This can be done by AGPS, or by storing the data locally on
device and restoring it to receiver on next power up, given we have correct
RTC and didn't move too far since last usage of GPS.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 194 bytes
Desc: This is a digitally signed message part.
Url : http://lists.openmoko.org/pipermail/openmoko-devel/attachments/20080706/4bc7010d/attachment-0001.pgp
More information about the openmoko-devel