[FOSS-GPS] Re: FoxtrotGPS/libgps w/ fso-gpsd

[James Hiebert]

Josh,

Thanks for looking in to those package conflicts.  With that explaination
(and the tonnes of reading and gps debugging that I've been doing over the
last few days), I'm finally starting to wrap my head around all of this.

On Fri, Oct 15, 2010 at 08:47:16AM +0300, Timo Juhani Lindfors wrote:
> Joshua Judson Rosen <rozzin at geekspace.com> writes:
> > Would you be willing/able to contribute toward updating fso-gpsd?
> 
> Would an alternative be to have ogpsd feed nmea or ubx to real gpsd?

Well on my Freerunner, ogpsd gets UBX packets from the ogpsd.gpsdevice. 
Seems like it'd be relatively straightforward to just pass them through, if
esr-gpsd can consume them.  This seems like a bad idea, though.  I would
assume that the gpsd layer is there for a reason... mostly so that the
application can be insulated from gps and hardware specific issues.  Such
an argument is addressed here:
http://gpsd.berlios.de/faq.html#why_not_parse_nmea

Still, I can't help feeling like foxtrotgps should at least have an _option_
of using dbus rather than libgps.  At least I'm coming at this from the
perspective of an embedded user.  I want my device to conserve battery
power, and conserve SD usage, because sometimes I'm out in the wilderness
for several days between opportunities to charge.  Having read this:
http://gypsy.freedesktop.org/why-not-gpsd.html
my understanding is that if we wrote a dbus interface for foxtrot, fox could
just register for the signals and then sleep between updates, conserving the
battery.

Not sure what the target audience is for foxtrot (whether it's primarily
Linux or other OSes), but seems like we could build it in as a Linux-only
option... and just use libgps otherwise.

Opinions?

~James

PS I _have_ finally gotten my Freerunner+fso-gpsd+foxtrot running again
after _way_ too many hours of debugging and fiddling.  Thanks for all of the
help; it's gone a long way in allowing me to understand the whole system. 
I'll keep my fingers crossed for the future. :)