On Fri 22 November 2013 18:22:40 thomasg wrote:
> On Fri, Nov 22, 2013 at 5:37 PM, Dr. H. Nikolaus Schaller
> 
> <h...@goldelico.com> wrote:
> > Am 22.11.2013 um 17:21 schrieb Lukas Märdian:
> >> Am 22.11.2013 23:23, schrieb Dr. H. Nikolaus Schaller:
> >>> Am 22.11.2013 um 15:46 schrieb Pascal Gosselin:
> >>>> What about GPS specifications ?  My company would have interest in
> >>>> multiple units if the GPS chip was capable of 5Hz or greater updates.
> >>>>  Recent GPS chipsets all seem to have GPS/GLONASS capability, which
> >>>> is very nice to have.
> >>> 
> >>> I think we can not easily change to use something different than the
> >>> WSG0084 using a Sirf IV.
> >> 
> >>> Unfortunately, the latest datasheet still isn't telling anything about 
the max. update rate and any updates in the firmware:
> >> On page 15 it says: "3: Defined as current drawn during continuous
> >> operation at a 10Hz update rate." Could this be a hint, that the module
> >> can actually operate at a max. update rate of 10Hz?
> > 
> > Unfortunately no. I also stumbled over this sentence but I think they
> > mean the update rate of the current probe, i.e. they did measuer the
> > supply current 10 times per second.
> > 
> >> Is there any GTA04 board, which already has a W2SG0084i installed?
> > 
> > Yes, about 50 or 80 (I don't remember the exact figure) since the
> > W2SG0004i was EOL and could easily be swapped. Unfortunately we don't
> > have a mapping to serial numbers.
> > 
> >> If
> >> so, we could try to query/set the output rate according to chap. 5 "NMEA
> >> Input Messages", using the message ID 103.
> > 
> > That one unfortunately only allows to specify the reporting rate in
> > multiples of 1 second, i.e. up to 255 seconds. But not 1/10 sec.
> > 
> >> Also chap. 6.2 "OSP Input
> >> Messages" look interesting, especially message 0x81.
> >> 
> >> Cheers,
> >> 
> >>  Lukas
> > 
> > Maybe someone knows a good technical contact to Wi2Wi?
> > I only have very indirect support though a distributor.
> 
> I don't think that will help you.
> The interface is SiRF's protocol, not Wi2Wi's and no documentation
> mentions of a mode above 1 Hz.
> To my knowledge, no SiRF chipset has support for a faster rate (at
> least in the frontend, internally, they might).
> So for 5/10 Hz a u-blox would be needed (or a SkyTraq, which are
> available up to 20 Hz).

The question arises what for a update rate of >1Hz is useful anyway. Given the 
precision and jitter in GPS position fixes, a higher rate would probably be 
useful only for speed values which are derived from doppler effect and thus 
independant from the positions the GPS chip calculates. Given the assumption 
that the GPS equipment is mounted inside a mobile object to calculate data 
about that object's movement and position, maybe exploiting other generic data 
sources like accelerometer and gyro might yield better results when combined 
with a pretty standard 1Hz GPS.

/j
-- 
()  ascii ribbon campaign - against html e-mail     
/\  www.asciiribbon.org   - against proprietary attachments
(alas the above page got scrapped due to resignation(!!), so here some 
supplementary links:)
http://www.georgedillon.com/web/html_email_is_evil.shtml          
http://www.nonhtmlmail.org/campaign.html
http://www.georgedillon.com/web/html_email_is_evil_still.shtml    
http://www.gerstbach.at/2004/ascii/ (German)

Attachment: signature.asc
Description: This is a digitally signed message part.

_______________________________________________
Openmoko community mailing list
community@lists.openmoko.org
http://lists.openmoko.org/mailman/listinfo/community

Reply via email to