Get data out of a Garmin GPS 18 USB

Greetings

I need to get raw GPS data out of a Garmin GPS 18 USB device.

This is quiet hard because of the USB interface. The data only comes in
the Garmin protocol format and also the USB interface is not very well
accessible for higher programming languages like Java.

Now my question is:

Has anyone ever extracted the non-NMEA data out of the USB device?

The only way I managed to get anything at all out of the device was to
use the GPSGate Software from Franson. But unfortunately it only
provides the NMEA data. So I m still unable to send the command to
activate the additional data like the pseudo range, and also unable to
get anything directly.

The best help would be a code fragment which fits into the SDK which is
provided by Garmin itself. They provide a small program written in C
which sends the device the command to send its product data, receives
it and display it.

Unfortunately the process to get the satellite raw data is much more
complicated and it was impossible for me to get any further code or
help from Garmin.

So any help from anyone would be fantastic ;-)
It would be already great to get a software which can write the
non-nmea data in a text file or something... of course a dll or
anything else closer to programming would be better but I would be glad
to get anything at all.


Thanks in advance for any hints.

Best regards,

Bertram Weckmann

[..]


Try freshmeat.net, enter "Garmin" in the search box, dunno about
your receiver, but there are quite a few apps able to talk to
Garmin receiver. Mostly if not all OSS, unsure if they can be
made working on doze. Most I've tried work fine on Linux, now if
we only could get Garmin mapsource running...

Good luck

--
mail: echo zvpunry@urvzvat.qr | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 193: Did you pay the new Support Fee?

I've put together some software for reading raw data from the unit.
It's not "ready for prime time", but I'm willing to share it. (For
personal, non-commercial use only). At the moment, it is just a set of
C++ classes using Garmin's USB driver. They're stuffed into a simple
console app to produced Rinex data. I'm intending to write a GUI
interface, but I won't get around to it for a while.

If you're interested, remind me with e-mail in a week or so. I'm
currently in the middle of doing a Lassen IQ class. I've reworked my
definitions and need to bring the Garmin stuff up to date.

- John
google@coyotebush.net

Hi John!

I'm a student at the Royal Institute of Technology in Sweden and would
be very interested in your source code for educational purposes.

I would greatly appreciate any source code! If you would like to share
it, I can be contacted at
nille_at_kth@hotmail.com

Thanks in advance!
Nille

John wrote:
of

weckmann wrote:


To the question, I have not heard of anyone doing it. I have noticed
that the GPS 18 USB, 18 PC, and 18 LVC models all appear identical
except for the cables and connectors.

Do you know how many conductors are in the cable on the 18 USB? Or how
many connection points there are for conductors on the GPS 18 USB
antenna/receiver module inside the case?

The antenna/receiver module is sealed and may be hard to open in a "non
destructive" manner. But it also may be that the gps 18 USB module has
unused connections inside the module for both USB and RS-232.

There are a number of mouse or puck style GPS receivers on the market
similar to the GPS 18 (and also made in Taiwan) that come with a
mini-DIN connector that has a pair of pins for RS-232 TXD and RXD and
another pair or pins that are usually called TTL TX and TTL RX or
something similar to that. On these, you can buy a number of different
cables to attach to the mini-DIN connector to adapt it to various PDAs
and power sources.

My understanding is that the TTL TX and TTL RX conductors are the ones
used for USB. But I'm not much on electronics and do not know if the
TTL TX and RX conductors can simply be connected directly to the two USB
port data pins or if there needs to be some intermediate electronics.
Maybe someone here can answer that question.

But if the RS-232 connectors can be found inside the GPS 18 USB, it may
be that you can get the control you want for it using the same utility
used for the GPS 18 PC and GPS 18 LVC. The hardware and firmware may be
the same in all the GPS 18 models with only the connections and cabling
varying.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)