Peter Bennett wrote:

On Thu, 17 Feb 2005 13:42:35 -0500, Jack Erbes
wrote:



For the most part, I would not buy hardware from Garmin because it would
mean I could use only Garmin's mapping/charting packages. Further, any
interoperability (automobile, marine, topo, etc.) would be limited to
what they wanted to market or allow and require additional purchases of
more Garmin mapping packages.


Almost all Garmin GPS receivers, like most other makes, will output
NMEA-0183 format data, which can be read by virtually all mapping
programs.

Garmin recievers only use the Garmin protocol for uploading and
downloading waypoints and routes, and for uploading Garmin's
proprietary maps or charts. Many non-Garmin programs can use the
Garmin protocol for waypoint and route transfers.

In my general inexperience with things Garmin, I may have some mistaken
impressions about the effect of the Garmin protocol. I thought data in
the Garmin proprietary format would not be read or used by an
application not specifically written to use it. In other words, if an
application was looking for NMEA data strings, it would not read any of
the Garmin proprietary data strings would it?

And I'm not trying to argue the point, I'm trying to learn more. Just
in case I have not already established my level of expertise here, I'll
say know that I know about enough to be dangerous. :)

Jack

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

On Fri, 18 Feb 2005 14:15:12 -0500, Jack Erbes
wrote:

Peter Bennett wrote:

Garmin recievers only use the Garmin protocol for uploading and
downloading waypoints and routes, and for uploading Garmin's
proprietary maps or charts. Many non-Garmin programs can use the
Garmin protocol for waypoint and route transfers.

In my general inexperience with things Garmin, I may have some mistaken
impressions about the effect of the Garmin protocol. I thought data in
the Garmin proprietary format would not be read or used by an
application not specifically written to use it. In other words, if an
application was looking for NMEA data strings, it would not read any of
the Garmin proprietary data strings would it?

That is correct. You have to manually switch the Garmin receiver
between Garmin and

And I'm not trying to argue the point, I'm trying to learn more. Just
in case I have not already established my level of expertise here, I'll
say know that I know about enough to be dangerous. :)

Jack

--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

On Fri, 18 Feb 2005 14:15:12 -0500, Jack Erbes
wrote:

Peter Bennett wrote:
(hit the wrong button on the previous post...)
Garmin recievers only use the Garmin protocol for uploading and
downloading waypoints and routes, and for uploading Garmin's
proprietary maps or charts. Many non-Garmin programs can use the
Garmin protocol for waypoint and route transfers.

In my general inexperience with things Garmin, I may have some mistaken
impressions about the effect of the Garmin protocol. I thought data in
the Garmin proprietary format would not be read or used by an
application not specifically written to use it. In other words, if an
application was looking for NMEA data strings, it would not read any of
the Garmin proprietary data strings would it?

That is correct. You have to manually switch the GPS receiver between
Garmin and NMEA modes. Some programs (like Ozi Explorer) know enough
to switch modes and baud rates (Garmin protocol uses 9600, NMEA uses
4800) when you ask them to transfer waypoints.

One marine charting program is too smart - if you tell it you have a
Garmin receiver, it insists on using Garmin protocol instead of NMEA
to get the real-time navigation data. If you want to feed NMEA data
from the GPS to an autopilot or DSC radio, you have to lie to the
program, telling it you have a Generic NMEA source, so you can leave
the GPS in NMEA mode.

And I'm not trying to argue the point, I'm trying to learn more. Just
in case I have not already established my level of expertise here, I'll
say know that I know about enough to be dangerous. :)

Jack

--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

"Jack Erbes" wrote in message
...
In my general inexperience with things Garmin, I may have some mistaken
impressions about the effect of the Garmin protocol. I thought data in
the Garmin proprietary format would not be read or used by an
application not specifically written to use it. In other words, if an
application was looking for NMEA data strings, it would not read any of
the Garmin proprietary data strings would it?

You are mixing up two things here. Firstly, there is the Garmin protocol.
This is a proprietary *protocol* consisting of binary (non human-readable)
data at 9600 baud.

Secondly, there are proprietary *sentences* or data strings, which are human
readable text, at 4800 baud. These sentences are called proprietary because
they are not defined by the NMEA standard. They have the standard NMEA
sentence format, starting with $P to indicate that they are Proprietary and
ending with a Carriage Return/Linefeed combo like any other NMEA sentence,
but the actual contents is entirely up to the manufacturer of the device.

The difference is for instance that proprietary NMEA sentences will be
passed by NMEA equipment like multiplexers and NMEA-linked instruments, but
a proprietary protocol will not.

Meindert

Meindert Sprang wrote:

"Jack Erbes" wrote in message
...

In my general inexperience with things Garmin, I may have some mistaken
impressions about the effect of the Garmin protocol. I thought data in
the Garmin proprietary format would not be read or used by an
application not specifically written to use it. In other words, if an
application was looking for NMEA data strings, it would not read any of
the Garmin proprietary data strings would it?


You are mixing up two things here. Firstly, there is the Garmin protocol.
This is a proprietary *protocol* consisting of binary (non human-readable)
data at 9600 baud.

Secondly, there are proprietary *sentences* or data strings snip

Okay, thanks to Peter Bennet's posts and yours I'm smarter about both
NMEA and the Garmin protocol and sentences.

Jack

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