Why Garmin doesn't use USB.

[+aka Monkey]

I emailed Garmin and asked them why they don't offer USB connectors for their products, and this was the response I got:

 

"The GPS industry has a standard that data such as waypoints, routes and track information has to transfer at a serial rate of 4800 baud. As you know if we were to use a USB connector the information would be transferred as quickly as possible. We have started adding both options to some of our

new products such as the Street Pilot 2610. Unfortunately the standard we need to follow is not a computer based standard. I do see a change beginning to happen, however it will not be a sudden change. The best solutions that Garmin can offer now if a computer is without a serial port is to use a USB to serial adapter or to look into a PCMCIA card."

 

Correct me if I'm wrong, but whenever I transfer data to my GPS, it seems it connect at a much higher data rate than 4800 baud.

 

Can anyone else shed any light on this?

[+Prime Suspect]

You can set it to transmit at a higher speed, but it won't do any good if the target can't accept data at that speed. You would have no way (normally) of knowing that they've handshaked at a lower speed.

 

"Don't mess with a geocacher. We know all the best places to hide a body."

[dzavetsky]

Maybe I dont understand the technology specific to GPss, but here is my thoughts anyways...

 

I would think that the speed at which the data is transferred is SOLELY dependent on two things: 1) The PC being used to send thedata and what connection it has and 2) the device accepting th data and what conenction type it has and how fast a speed its processor can support.....If one or the other doesnt support USB, then that is the issue....

 

I dont see how the data cares one way or the otehr how fast it is transferred.....Seems to me like the GPS is the weak leak, in that the relatively slow processor in current GPSs cant handle the data flow from USB....

 

Just *my* opine...

 

DZ

[AKap]

I think that "4800 baud" mentioned in the response from Garmin is part of the NMEA standard for communication between various electronic equipement such as GSPr, auto-pilot, compass, etc. You can transfer data faster, but you won't be NMEA compliant.

[+Renegade Knight]

AKap I think has it right. NEMA controls and NEMA is serial and slow.

 

If Garmin has the ability to go faster in it's own software than the 4800 baud then great (Mines is 9600) but that's a Garmin thing. Magellan might do the same, but it would not be using a standard that is anything but magellan only.

[+trippy1976]

You would think that a USB port could be slowed down when required to fulfill a standard like NMEA, but when it's in "Garmin" format... they should be able to do it lickity split.

 

Garmin (and anyone) could get around the whole USB issue if they would use industry standard removable memory like SD Ram or Compact Flash. Then you could just use a USB reader to load maps, waypoints, etc.

 

--------

trippy1976 - Team KKF2A

Assimilating golf balls - one geocache at a time.

[+Lone Duck]

It's not just the memory though, it's also the use of a GPSr when hooked up to a laptop. The communication is full duplex, or two-way in that case because each end needs to talk to the other. While a faster standard would work fine with a computer, it's the current design of the other devices that can be hooked up to a GPSr that wouldn't be able communicate, because they would be flooded with data faster than they are designed to process it.

 

That Quack Cacher:

Lone Duck

 

When you don't know where you're going, every road will take you there.

[ChiefPig]

Can't the software control the speed of the data transfer in USB? I know USB 1.1 is 12Mbps and USB 2.0 is 480 Mbps, but can't the software slow down the transfer to 4800 baud? If the 'ancient' phone modems can control the speed of transfer, I am assuming the high tech USB can do the same.

[+TotemLake]

The modem is an end device connected to either the ISA, EISA, PCI or serial port. That is, the capability is built into the device and the software aids its ability by selecting the options.

 

To carry that further, because the GPS receivers have not been built to really support anything beyond NMEA standards, the capability to control the speed via cable to PC was not built in.

 

Given today's technology, and the marketing geared towards anybody who might be the least bit tech savvy... they really should have built in that capability. To hide behind NMEA standards merely obfuscates admiitting they lacked the foresight of how this particular device would take off. In essence, the PC interface was merely an afterthought and it is a classical case of the engineering group determing what the customer wants with little regard to what the customer said they wanted.

 

Granted, this general sporting use of the GPSr is relatively new and can be akin to the PC and related software producers back in the early 90's versus the hardware/software vendors today.

 

It'll eventually catch up with today's technology, perhaps even moving forward to something like firewire or bluetooth instead of USB. They just need to hammer out the standards the same way the computer industry did.

 

Cheers!

TL

[peter]

quote:

---

Originally posted by TotemLake:

To carry that further, because the GPS receivers have not been built to really support anything beyond NMEA standards, the capability to control the speed via cable to PC was not built in.

---

 

This is clearly not the case for either Garmin or Magellan GPS receivers. Both support NMEA standards which call for 4800 baud on an RS-232 like link, but they also support substantially higher baud rates when connected to devices that are not NMEA. On Garmin devices the baud rate is 9600 for transfers of tracks, waypoints, and routes, and is adjusted upward to 115,200 baud for transferring map data. Magellans also support multiple baud rates - up to at least 19,200 (maybe faster?). So the devices do support letting the PC software control the speed of the transfer.

 

But 115,200 is about the limit for the RS-232 type of interface whereas newer serial interface specs like USB can go considerably faster. If Garmin and others replace the RS-232 port with USB (or BT, etc.) then there's a problem for all the users that need the GPS to talk to their other NMEA devices (auto-pilots, rangefinders, radars, depthfinders, etc.). So supporting USB probably means adding another port plus the current RS-232. That adds extra cost and explains why the industry has been reluctant to do so in the past.

 

I expect that as the memory sizes for maps continue to grow we'll soon see new physical interfaces that support higher speeds for new GPS designs. Loading a Legend's 8MB takes about 20 minutes at 115,200 baud and is still reasonable. The Vista with 24 MB takes almost an hour and is reaching the limit of what people will accept. New designs with 64 MB or more will need either replaceable memory cards (like Meridian, eMap, iQue) and/or built-in highspeed interfaces.

[+TotemLake]

I know somewhere in these forums (and I'm not taking the time to look for it now), it has been stated and shown the higher speeds in excess of 4800bps can produce erroneous data transfers between GPS and computer. The GPS simply is not built to handle the appropriate checks on the data packets. It depends on a steady, uninterrupted stream. The RS232 on the PC will take and feed anything you want to set it at as this is a hardware issue and has nothing to do with the handshake or checks and balances. Thats why, if your GPS is set to NMEA on in any version you care to use and powered up during bootup, the GPS will be identified as a mouse upon bootup on the serial port. There is nothing built in the GPS to stop the stream of data until it is asked for. Your system, once it identifies the GPS as a mouse, will accept any input directed at your cursor and cause all kinds of things to happen on your system.

 

Cheers!

TL

[vagabond]

Well if I remember when I first got my maggy, the baude rate for mapsend topo was 4800, same as MS s&t also nema was on, guess it had to be slower with the mapping, but whith easy gps baude rate was 9600 nema off, latest version baude rate 4800. nema off. for what its worth.

My new Gateway laptop has no serial port so I had to go with a usb adapter no problems everything works great.

When I download regions to the sdcard, The latest version of mapsend topo 4.20c sets it up then asks if I want to download to the gps or another port, heres the good part downloading to another port 20 mins. total time for a 128 meg card

 

All who look are not lost

[+quakemap]

I think the industry just overlooked USB - and now the Bluetooth is coming and there is no much sense to catch up with the older USB technology. Having USB-only connection would cut out many potential customers, having both USB and Serial - drive the price up. Existing software relies on RS232 heavily.

 

As for speeds and protocols:

-- Magellan works fine up to 115000 baud with it's NMEA-like protocol, but with handshaking it is still slow, and without - unreliable.

-- Garmin has it's own network-like protocol, working at 9600 baud, very old and reliable enough in its own convoluded ways.

Both companies are heavily invested in their protocols and won't change anything any time soon.

 

http://www.quakemap.com - redefining Easy...

[STREETSEAL & G.I. Jane]

I use a garmin usb data card programmer with my

GPSmap 176c, It programs map cards quickly, If I leave the data card in the unit which is connected via "cereal" it takes about 2 hours to fill a 32 mb data card. It sucks, I think only a few units use the removable memory, Mostly marine chartplotters, the Streetpilot too. I wish the E-trex series had usb, my vista takes about about 1 hr to fill the memory. I'm impatient, like the rest of us

[+RobAGD]

Well for my laptop I went the way of getting a PCMCIA Serial card. Those puppie are not cheap. I got a ruggedized one that cost $140. I found 1 that was $100 or so and they looked like junk.

 

The really cool dual port and silly fast speeds were running close to $200.

 

I had issues with the USB to Serial converters causing blue screen on my XP box so instead if just buying and trying differnt converters I just said the heck with it and got the card.

 

Works dadgum well, so far no issues.

 

-Robert

[usmcski]

would I need to download some special driver or something to connect my rino 110 via a usb? I have the serial to usb adapter but the pc is not recognizing the gps.

[+kevin917z]

yes you need a driver, the company that made the adapter should have drivers on their website or do a google search, without the driver it will not work

[+aka Monkey]

Good discussion! The NMEA standard certainly seems to be the culprit, and I suppose Garmin feels limited due to the size/cost constraints of adding an additional USB port. I suppose by the time we finally see USB ports as standard on Garmin GPS, people will be asking why they aren't using Firewire 800.

 

I must admit, my primary reason for asking was because I'm on a Mac, and while it's possible to run the MapSource software under VirtualPC, getting it to communicate with the GPS via a USB-Serial adapter has been less than consistent.

[+nincehelser]

What I don't understand is why Garmin just won't partner or simply recommend particular USB/Serial adapaters that work well with their products.

 

For now I've given up looking for an adapter for my laptop, and I'm considering getting the new Earthmate which is USB native. (At least for computer apps that need to talk realtime with the GPS...it still doesn't solve waypoint upload/download problem)

 

I've tried a few different USB adapaters. They've ranged from not working at all, to working part time, to crashing my machine. I'd really like to find one that works smoothly and without fuss (I have a Compaq Pentium 4 laptop running XP)

 

George

 

[This message was edited by nincehelser on September 06, 2003 at 10:36 AM.]

[vagabond]

Originally posted by nincehelser:

 

I've tried a few different USB adapaters. They've ranged from not working at all, to working part time, to crashing my machine. I'd really like to find one that works smoothly and without fuss (I have a Compaq Pentium 4 laptop running XP)

 

You might want to try SIIG.com Been using one of their usb serial adapters for about a month now with my gateway laptop running xp, and have had no problems, yet

George

 

All who look are not lost

[+apersson850]

I'm using two different old Entrega/Xircom adapters. They both work perfectly with the Vista. No problem at all that's dependent upon the USB/RS 232 converter.

(Could be other problems, like HotSync grabbing a port and so, but that's not the adapters fault.)

You can't buy these models any longer, unfortunately.

 

Anders

[+aka Monkey]

quote:

---

Originally posted by nincehelser:

What I don't understand is why Garmin just won't partner or simply recommend particular USB/Serial adapaters that work well with their products.

---

 

The problem is that what works great on one person's machine won't work on someone else's. It's one of the things about the PC that makes me want to gouge my eyes out of my head. Also, once Garmin starts recommending a particular piece of hardware, people will start calling Garmin when they can't get it to work and exclaiming "But you said it was compatible on your website!"

 

Microsoft claims that 50% of all system crashes in Windows are due to third-party software. Of course, this means that the other 50% is due to their operating system. Either way, it adds up to 100% crashes.

[+Hiemdahl]

Check out www.fugawi.com they have a USB/serial adaptor with drivers that works with Garmin. I think it is under $30 US.

[+aka Monkey]

I thought you were kidding about the name... A mapping company named Fugawi? This is too much of a coincidence to be anything but intentional.

 

See, there used to be a tribe of pygmies who wandered the plains of Africa. They were very short (being pygmies), and as they would wander through the tall gasses, they would repeatedly jump in the air to have a look around, all the while yelling "We're the Fugawi! We're the Fugawi!"

 

Say it out loud.

[+Hiemdahl]

Yep, the preident of the company will look you in the eye and with a straight face tell you there is no relatinship.

 

BTW, it is one of the absolute best mapping software available. Used by the military from numerous countries.

[+New England n00b]

In addition to this, aren't there non-PC based devices that need to interact with the GPS units, hence the standard?

 

In other applications (industrial controls, etc.) you tend to see archaic standards still in use, so new devices need to be able to talk to them...

 

---------------------

Don't hurt me. I'm new here.

[+apersson850]

There is of course the possibility to go the other way, i.e. to equip the GPS with a USB port, and then provide a USB/serial converter from the manufacturer of the GPS. Then they could test one or two more, if they like, and say that we know it will work with the one we sell, and it will also work with A and B. C, D, E thru X may work, but that's up to you to find out.

Doing like this will upgrade the GPS units to todays standard when communicating with a PC, and still keep yesterday's standard when communicating with sounders, autopilots etc. while still allowing Garmin (or whoever) to be able to guarantee that some piece of equipment does actually work with their unit.

 

Anders

[+Hiemdahl]

http://www.fugawi.com/docs/hardframe.html

[TomBombadil79]

USB Serial Conversion

 

TomBombadil79

[+Clffhngr]

Hi, George,

I hate to admit this, but I just went to Radio shack and bought their USB to RS232 Cable. I started out not feeling good about buying from them and it got worse when I picked up the package and it included a floppy disk! Everyone that I know of has swithced to cds. Anyway I brought it home pluged the cable into my laptop and Rimo. Now everything is working fine. NO PROBLEMS !!

 

And as far as the Delorme Earthmate, I just returned mine to Delorme for a refund. It worked well with their software, but I had problems with third party software. Remember that many map applications won't look for a GPS on usb.

 

For now I've given up looking for an adapter for my laptop, and I'm considering getting the new Earthmate which is USB native. (At least for computer apps that need to talk realtime with the GPS...

 

[This message was edited by Clffhngr on September 16, 2003 at 12:18 AM.]

 

[This message was edited by Clffhngr on September 16, 2003 at 12:20 AM.]