One of the Neo1973's big selling points is its Hammerhead AGPS chip,
however (with the exception of a few P0 developers) we haven't been able
to do anything with it yet due to the lack of a driver.
I have recently joined the "Sphyrna" reverse-engineering project at
http://projects.linuxtogo.org/projects/sphyrna (linked from
http://wiki.openmoko.org/wiki/Hammerhead/Protocol), and with the
assistance of the information provided there I have put together a quick
and (very) dirty program called "satscan".
This program scans for signals from GPS satellites at several different
Doppler-shifted frequencies, as a real GPS receiver would do during a
"cold start" acquisition. It displays symbols on the screen representing
the strength of each detected signal.
That's _all_ that it does - this program does not receive any navigation
data from the satellites, does not compute a position fix, or anything
else. It is strictly a 'toy' application, but at least it lets you
confirm that your Neo1973 actually has a GPS chip installed. :)
It's available for download at:
http://members.shaw.ca/mmontour/satscan/satscan_1.0-r0_armv4t.ipk and it
was built against a fairly recent 2007.2 image. You might need to
"--force-depends" the installation. A source tarball is in the same
directory, but I can't provide assistance on how to set up your
development environment to build it.
I don't plan to maintain this program - it's a one-off demo. However I
will continue to contribute to the reverse-engineering efforts, and I
encourage any other interested developers to do the same.
- Playing around with GPS Mike Montour
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