GPS on XO
pgf at laptop.org
pgf at laptop.org
Sat Apr 4 10:20:20 EDT 2009
> >From the Testing summary
> > Roadmap-3
> > Map of California came up, could move around easily.
> Interesting timing. Thanks.
> I'm about to go on a long drive and it would be fun to be able
> to watch where I'm going on my XO. I've got a USB GPS device
> that shows up on lsusb as a Prolific serial port.
i'm the current maintainer of roadmap (not just the Activity), so
in theory i should be able to answer all your questions. roadmap
works very well for what you want to do, and can even help directly
guide you somewhere if you've preloaded it with a route to where
you want to go. what it can't do (that any modern GPS navigation
device will do these days) is figure out the route to your
> Are there any other activities or whatever on an XO that use
> input from a GPS device?
> I can't get much useful out of Roadmap-3. On startup, I get a
> street map of the San Francisco area, but scrolling doesn't
> update the map beyond the edge of the initial map and the help
> stuff doesn't do anything.
even though the maps that roadmap uses are pre-processed into a format
suitable for small devices, they're way too big to provide more than
a "demo sampler" with the Activity itself. so what you have is
state outlines for the whole country, and full details for just the
city of san francisco. just enough to whet a user's appetite, and
i'm pleased to see it worked. :-)
> Does anybody know how I can download/preload maps for a
> region? Or the help stuff?
the help screens in roadmap are available in HTML format. because
sugar still hasn't figured out how to make it easy for an activity
to present the user with information in a browser, the help isn't
packaged with the activity. probably short-sighted of me. in any
case, it's all available here:
you should also take a look at:
for some XO-specific information, though looking at it just now i
see it could use some fleshing out.
in particular, the part about getting maps should be more specific:
maps are big, so you'll want to put them on SD or USB. roadmap
will look for maps in a top-level directory called RoadMap.maps, plus
in any subdirectories of RoadMap.maps. as long as the full path is
"/media/<something-or-other>/RoadMap.maps/....", it should find them.
fetch maps of the states you want to visit from here:
create a RoadMap.maps directory on your storage device, and
unpack the tarballs you find at that page into that directory, and
(re)start RoadMap. you should then have a much fuller view of the
(for non-USA folk -- roadmap also has limited maps for canada (roads,
but no water features), as well as support for OpenStreetMap maps
which are quite good for many parts of the world.)
> Poking around on the menus...
> It finds my GPS device and displays a reasonable location. It says 0
> satellites, so I assume it wants more info. I've got a typical GPS toy
> speaking NMEA. What $GPxxx sentences does Roadmap want? It's currently
> setup to send only $GPRMC sentences.
roadmap will use GPRMC, GPGGA, GPGSA, GPGSV, and GPGLL. i believe if
you add at least some of those, you'll get the satellite count correctly.
i encourage you to join the roadmap mailing list -- there's only one
list for users and developers because the community is small and the
traffic level low.
paul fox, pgf at laptop.org
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