Garmin GPS goes (more) proprietary

by Simon St. Laurent

Garmin's most recent outdoor GPS units sport a USB port instead of the strange proprietary connector they used to have. That sounds great, except that Garmin's gone more proprietary on the protocol they use to send location data over that connection, abandoning NMEA in favor of Garmin's own protocol - exclusively.

I've been editing Mapping Hacks (coming soon), and marveling at the intricate dance between proprietary and open that swirls throughout the entire mapping space. Public data is great to have but often buried under or repackaged as for-pay products, in those countries where it's available. Mapping formats vary, but often have at least proprietary roots. GPS devices sometimes have their own protocols, but NMEA 0183 at least provided a baseline of openness, a common expectation software developers could rely upon.

While looking through the Amazon reviews for Garmin's latest Vista C and Legend C, I found some red flags:

However, the USB connectivity will only connect you to proprietary Garmin cartography software, it is NOT NMEA compatible. (Legend C)

It will no longer work with a Macintosh. The software loads and works easily using VPC as did the software for the prior version. However the USB driver provided by Garmin will not work with a Macintosh and there does not seem to be an alternative according to the technical support at Garmin. (Vista C)

Finally, although the Vista C includes a speedy USB port for transferring data to your PC, be aware that many third-party vendors can't or won't support it. DeLorme is a primary example. As a separate review of their TOPO 5.0 product states, DeLorme knows they can't read Garmin USB data, and despite frantic pleas for help from their customers, they have reacted with what can best be characterized as a huge yawn. (Vista C)

Curious, I called Garmin this morning. I didn't get the name of the lucky recipient of my call, which got angrier as it went on, but he confirmed that Garmin has in fact dropped NMEA support. He was happy to report that their protocol was in fact proprietary. I asked why they did this, and his reply was that "our engineers decided to support Garmin software." If I wanted that changed, my only recourse was to request a feature or buy a different unit.

I'll put in the feature request, though I can't say the phone call gave me much hope that Garmin is interested in any such change. We can, of course, use Garmin's protocol documentation, but that also has some interesting bits:

Q: The Internet has information about additional protocols and extensions that are not described in the document. Why have these been left out?

A: Part of the goal of the document is to separate what GARMIN thinks is safe versus what is unsafe when
interfacing to our GPS products. Any items left out of the document are considered to be “testing aids” for use by our engineering and manufacturing departments only. As such, we do not require all products to have all testing
aids, nor do we require the testing aids to be implemented in the same way in every product. In fact, there is a wide
variation in these testing aids. Worse, some testing aids may have side effects that are undesirable for anything but

Q: Where can I find example code (e.g., for converting time and position formats)?

A: We are currently unable to take the time to compile this information...

Q: Where can I find some sample data transfer dumps?

A: We are currently unable to take the time to compile this information.

6.13 of the Garmin specification does provide the PVT Data Protocol, "an alternative to NMEA so that the user may permanently choose the GARMIN format on the GPS instead of switching back and forth between NMEA format and GARMIN format." That may be the place to focus for people who want to use Garmin units but want to connect them to a broader range of software than Garmin itself provides. Some software already supports PVT, and more may have to unless Garmin has a change of heart.

Why would a manufacturer walk away from a baseline standard?


2004-10-14 15:31:20
That's terrible.
I have always supported Garmin because of their NMEA support. No more.
2004-10-17 18:54:31
Garmin pulling out of the Geocaching Market?
I've owned a lot of GPS models, and the old B&W eTrex Vista is one of the best for Geocaching.

When I Geocache, I use some shareware and home-grown software. When I hike in the forest, I use the Garmin map software. Sadly, the new Garmin models with specialized drivers and protocols pretty much prevent me from using geocaching software. Perhaps Garmin is planning to sell some yet-to-be-announced Geocaching package?

Happily, some of the obsolete Vista and Legend models are heavily discounted and are compatible with non-Garmin software and multiple computers. And those models are heavily discounted, so it's good that some people can still get the "good old classics" while they can.

I'm confident that other manufacturers will continue to support geocachers, and in fact this new Garmin direction will certainly help Garmin's competitors gain a lot of ground in the Geocaching market.

But it is sad that Garmin is retracting from the geocaching market that they helped develop.

2004-10-17 23:08:21
Garmin pulling out of the Geocaching Market?
I think it's just a matter of time before that geocaching software is upgraded to support the new units...

Manufacturers can't stick to old protocols and interfaces forever just because some third parties aren't ready or willing to update their products...

2004-10-17 23:11:29
common interface?
Maybe Garmin is working on a common interface for all their units in all markets.
If that's the case USB is a logical choice. A custom protocol would ensure they retain their market (extremely lucrative) of selling the data for those units. Especially the aviation units have high prices for data updates, running into the thousands of dollars a year for general aviation units like the GNS530 and even more for the larger units for commercial aircraft.

While in volume the small handhelds may outnumber such units, in income they're peanuts in comparison.

2004-10-18 06:34:57
not the interface you're describing
Garmin already has a proprietary but public interface for sending data and maps to its GPS units. They've had that protocol for years. There is non-Garmin software for sending data and maps. I suspect the creators of those tools would have an easier time if Garmin better documented its protocols, but that end of things is at least possible.

What's changed is that Garmin removed the NMEA 0183 protocol for communicating real-time information, which lets the device say "This device is currently at Lat X Long Y Alt Z" to a lot of other devices and programs. There isn't much software that supports Garmin's equivalent PVT, and it's not clear that there's any benefit to using PVT over NMEA.

They seem to have made widespread GPS-based hackery using relatively cheap devices more difficult in order to give their own software a pretty small edge over the competition.

2004-10-18 08:11:04
Garmin are making a mistake
This is the most retarded thing I've ever heard. I feel sorry for anyone who buys this GPS without realizing the implications. There are lots of programs out on the market, Microsoft Streets and Trips for example, that will work with ANY GPS because almost all GPS units support NMEA.

I bet they don't do this again!

2004-10-31 23:47:02
Now I bought a Garmin Vista C and......
...didn't know about this NMEA / prop. protocol facts. Damn ! Tried also to connect to my Mac - this doesn't work with USB only... Damn again.....

2005-01-29 20:05:01
Garmin and non-nmea
I'm new to GPS and thinking of purchasing a unit to attach to my laptop for some traveling. Any suggestions on an inexpensive way to go for this? something that is NMEA compatible and has voice enabled directions.
2005-01-29 20:07:25
Garmin and non-nmea
I'm new to GPS and thinking of purchasing a unit to attach to my laptop for some traveling. Any suggestions on an inexpensive way to go for this? something that is NMEA compatible and has voice enabled directions.
2005-02-02 04:00:35
Garmin to NMEA converter

You can try Franson GpsGate 1.10. It solves this problem. It creates a number of virtual serial ports old GPS applications can connect to, and convert the Garmin protocol to NMEA. You can in fact connect any number of GPS applications to the GPS at the same time.

2005-03-26 14:08:44
Garmin and non-nmea
I have used many versions of Delorme's street atlas with their branded gps. It is very easy to use and they continue to update the software for usability and street accuracy. It even has voice commands and audible information about the trip/route you are driveing.

For about $100 and your laptop and you will be up and running in no time.

Happy with their products.

2005-03-26 14:12:40
Garmin to NMEA converter
I found this dialog by reviewing search results for the Garmin eTrex Vista C which looked like a great handheld GPS unit.

I am looking for a device that I can use while expedition kayaking down wild rivers like the Rio Grande below Big Bend in Texas. Is there a company/product that does not have the proprietary bent that Garmin seems to be displaying?

Waterproofand easy to use?


2005-04-08 14:48:02
Now I bought a Garmin Vista C and......
FYI, the opensource MacGPSBabel, v. 1.2.5, works perfectly to upload/download waypoints, routes, and tracks to a Vista C. I've been using it for a week now on both a Powermac G5 and a Powerbook G4, and my Vista C.
2005-04-13 07:18:27
Now I bought a Garmin Vista C and......
I've got Mac GPSBabel, and everything works well when I download from the Vista C to my iBook Panther 10.3.8 (.gpx), but nothing happens when I upload road files or waypoint filescreated with gpsWrite 1.7.5 (.gps).
What kind of output format do you use for upload, and what soft do you use to create and edit waypoints, tracks, etc... ?


2005-05-19 16:54:32
Now I bought a Garmin Vista C and......
OK now I am confused. From what I've read Garmin doesn't make a USB driver for a Mac and has its own propriatary protocols and does not follow the NMEA standard. I have a Powerebook G4 and want to transfer waypoints to my new Garmin Vista C. According to MacGPSBabel documentation this is only supposed to work on a Windows machine. "New in GPSBabel 1.2.4 is USB support, but only under Windows." Yet you did it on a Powerbook. Please tell me more on how you did it. Did you use Virtual PC? Where did you find a USB driver?


2005-07-13 15:03:42
Garmin are making a mistake
What handheld GPS device do you use with MS Streets and Trips? Would you recommend it? Any others that you would recommend?
2005-08-16 13:09:54
Contact Garmin... I did
I called them at (913) 397-8200. I explained I have an eTrex Legend and was considering upgrading to a color Legend. I explained I use Mappoint with my GPS which uses the NMEA protocol and had read some stuff which indicted NMEA support was dropped by Garmin. The lady I spoke with was very nice and gave me a good explaination.

To meet market demand, Garmin has started producing some units with a USB connector instead of traditional serial. Unfortunately, the way the NMEA protocol works, it will not function over a USB link. So the bottom line is Garmin has not dropped NMEA support, they simply are unable to provide NMEA support over USB. Technical problem, not a marketing strategy.

We continued our discussion about how something will need to give in the industry. Most newer laptops do not include a traditional serial port - they are USB only - and most GPS software relies on NMEA which requires traditional serial. We discussed the possibilities of the NMEA protocol being updated, but she was unsure of any traction in that area.

I did suggest they put together a white paper to post on their website explaining why NMEA is no longer an option with USB. That would quell a lot of unfounded negative feelings towards Garmin.

2005-08-16 13:55:20
not really an explanation
because lots and lots of other vendors provide NMEA data over a USB link. USB isn't precisely the serial link NMEA was designed for, but serial data still flows over USB just fine.

I'm sorry, but you've been snowed.

2006-02-08 11:16:23
GARMIN, USB, NMEA1083 Made Simple
Hello All, The Solution Is Simple If You Understand The Technology. Up to the release of the new X series models, all Garmin GPS systems used the same Garmin 12-channel receiver. The difference between models if the housing configuration, the microprocessor inside and the operating system and its features. So with this in mind, purchase a Garmin system with the ability to add an external antenna, and have the serial port. Now, purchase a good quality serial to USB Interface. I have enjoyed using GPS technology for maps, and software for many years now and have, through experience, come up with this simple and practical solution. Furthermore, I have wasted hours going to the large retail chain stores and purchased USB-to-serial-converter only to find them to be of extremely poor quality - resulting in crashing my system often. I now use as my source. They offer several Garmin tested Serial-To-USB microcomputer interfaces designed for mobile use. I have not had a problem. They also offer a professional USGS map program that support the GARMIN USB port. However, the Garmin USB protocol does not send as much position data as does the NMEA 1083 standards. Mr Casanova offers a very simple and detailed explanation and insight, which i found very useful... find it here One last note, I have tried the other brands and none come close to the Garmin MapSource combination... stick with Garmin. The newer models with USB are strictly for the general public, who are not going to read the instructions of anything and do ot have the will to bother with it... they simply demanded that they wanted their Garmin to plug into their new laptop. Simple.. Consumer demand dictates over logic. As for reviews… remember, unless the person writing the review is an actual user of the technology, their review is only a personal opinion based on their own experience and knowledge. Best place for answers are the people that designed the equipment… they design their products for a particular use and/or user. Now Get Outdoors!
2006-02-08 11:35:56
The solution is simple: don't buy Garmin
Every other manufacturer's USB devices provide NMEA 0183 output perfectly fine, whatever Garmin's protestations about it being impossible may be.

This consumer has made a very simple decision: don't buy Garmin devices until they realize that using their proprietary USB protocol exclusively is a bad idea - and change.

On MapSource, I agree that nothing comes close - if you enjoy broken software. Apparently I'm not the only one who feels that way:

2006-02-08 11:43:48
LapTop Navigation Software
I use the Microsoft Streets And Trips In Combination with Garmin's MapSource And a Garmin GPS. The Garmin Bluetooth GPS from Casanova's is great for laptop users. I tried the Rand McNally, DeLorme Street Atlas, Both are very crude by today's computing standards... go with Microsoft And Garmin Combination... (I use MapSource to plan routes and check out points of interests, I use Microsoft Streets and Trips to plan out the route and provide me with gas cost, time and road construction info...while driving I use Garmin's nRoute from Casanova's. I also have the Microsoft Streets And Trips loaded, and use it as another reference resource... the more reference resources one hands the better (simple logic). I found Casanova's to be the best place for the information, since they actually test run the products under real conditions for long periods of time...not just a rewritten review or instruction manual. They offer screen capture details of the various programs and only offer programs they have tested and validate as having some real value to their customers, a rare thing in today’s world of sellers and corporate scams! I also feel good about them being an authorized established dealer who provides valued service. They offered me a bundle packed “ready to use” by their GPS experts. This is what I wanted. I have no resources to keep buying software I am stuck with, so now I only use CasanovasAdventures as my outfitter. Find the online GPS info here Their map section is at
2006-02-08 20:30:03
Garmin to NMEA converter
Problem is the Garmin units, Like you need a VistaC for what you plan, are the best operating and mapping units on the market. All this crap about NMEA is just to use the off brand map programs. I bought a cheap NMEA USB GPS"mouse " for $50 to use with the Microsoft Autoroute and Streets on my laptop - It is OK, but the MORE Expensive GArmin Mapsource /NRoute really does work better. I was upset that GArmin did this after I bought my Legend C. Suddenly my laptop would not recognize it! The older Legwend serial port GPS did/does have NMEA.