HomeHardware


i-Blue GM-2 USB GPS Receiver
OneRVer
10-4, I will leave it alone. So if I picked the wrong baud rate it would not work, right?
tcassidy
Right, you lucked out again. This must be your week!


Terry
MrUmbra
Quote:
Originally Posted by OneRVer
10-4, I will leave it alone. So if I picked the wrong baud rate it would not work, right?
It's just a matter of setting the baud rate in the navigation program to match the baud rate the GPS is sending. If it ain't broke then fix it till it is.

The GM-2 was a good choice and should serve you well.

--- CHAS
Ken in Regina
Just as a point of interest, the version of GPSView that ships with the GM-2 is much nicer than the older version we are recommending. It's a better layout in almost every imaginable way.

But it won't let you set the BAUD rate. That's the only reason we are recommending downloading and using the the older version we have posted here ... if someone is having trouble getting things to work and needs to force the GM-2 to use a different BAUD rate. That's the only reason to use it. Otherwise the newer version is so much better.

I have both versions installed on my computer. I use the newer version any time I want to check out a GPS receiver or do some troubleshooting. I almost never use the older one ... only when I need to force the GM-2 or the i.Trek M7 (in USB mode) to use a different BAUD rate.

...ken...
tcassidy
Unfortunately Ken, the program is included with a device for which it has little or no value. While it is true you can use it to change the refresh rate, what good is that for a device that can only do 9600 bps. You might be able to up the frequency to twice a second but 5Hz - forget it.

To fully experience the advertised capabilities of this device, you need to be able to control both the refresh rate and bite rate. That needs the older, less sexy and more crash prone version of GPS View.

Terry
Ken in Regina
I wasn't trying to apologize for the company, Terry. They include the program; they didn't write it.

I was just trying to point out that we should not overlook the general goodness of the newer version just because we need to use the old one for one feature. As I said, as long as I don't have to force the BAUD rate to change on the receiver, I find the new version is so much better in every way than the old version. That has nothing to do with the company's mistake in including a setup utility that lacks one necessary feature.

On the other hand, the utility wouldn't even be necessary most of the time in these situations if Microsoft could be persuaded to bring Streets&Trips communication routines into at least the 20th century. It's the only one that has this problem because it's stuck at a single BAUD rate, a BAUD rate that won't support even 2Hz update frequency.

It would be so simple to change that it baffles me why they still refuse to do it.

...ken...
tcassidy
If you advertise a product can do all those wonderful bit and refresh rates, why not ship a utility with it that supports at least some of your claims.

I am surprised that a company selling an excellent GPS in the North American market should settle on 9600 bps. The European market certainly seems to favour that rate for reasons I don't understand but here - 4800 is the gold standard.

Who cares about refresh rate anyway. I can remember using Streets on a PDA at 1/5Hz, not because Streets couldn't go faster, but the PDA couldn't! Now that was purgatory.

Terry
Marvin Hlavac
Yes, no software would have an issue with 4800 / 1 Hz. I wish that was the default configuration of i-Blue GM-2.

People who buy GM-2 specifically because of the 5 Hz ability, are all likely more advanced technically, and for them using the GPSview utility would present less of a challenge than to those without any technical knowledge, who have simply bought GM2 because that's what they have happened to stumble upon.
Ken in Regina
Quote:
Originally Posted by tcassidy
If you advertise a product can do all those wonderful bit and refresh rates, why not ship a utility with it that supports at least some of your claims.
Of course. I agree and said so. But you're really hung on that??? So badly you can't see that the newer version of GPSView is hugely better than the old one???

@Marvin, I still think the real issue is Microsoft's refusal to replace that terribly outdated COM code. It's not that it's outdated in 2010; it was outdated in 1990. Seriously. I can't remember when the COM routines in standard code libraries didn't include the ability to do all of the standard BAUD rates. Heck, I was writing COM code in the '70s that did the, then, standard BAUD rates, which included everything up to 14,400. So even if Microsoft met 1977 coding standards this problem would just go away.

I had no difficulties with any of the other programs I tried the GM-2 with .. DeLorme Street Atlas 2011, Garmin Mobile PC 2009 and iNav iGuidance 2009. I didn't try it with MapFactor but I'm sure it would also work perfectly well with it.

...ken...
tcassidy
The new version of GPSView does not seem to be widely available. I can't recommend it to others if I can't find it. I usually stick to Earthbridge because it does what I want and is readily downloadable.

I agree that all navigation programs should be able to use up 115200 so there would be no problems with new (or old) GPS devices. The only ones I know that can't are Streets & Trips (4800) and Mobile PC (38400). But if a device can do 4800, why not default to that. There is no advantage to 9600 anyways.

Terry
OneRVer
Quote:
Originally Posted by Marvin Hlavac
Yes, no software would have an issue with 4800 / 1 Hz. I wish that was the default configuration of i-Blue GM-2.

People who buy GM-2 specifically because of the 5 Hz ability, are all likely more advanced technically, and for them using the GPSview utility would present less of a challenge than to those without any technical knowledge, who have simply bought GM2 because that's what they have happened to stumble upon.

Well I bought the GM-2 because of your write up Marvin.

GPSview??? The only change you can make, as far as I can see, is the Hz rate. I assume the when it is set at 1, the receiver scans from 1 to 5. Set to 2, 3, 4, or 5 and you are stuck at that rate. Am I close???

I do not understand on their web page this, NMEA0183 v3.1 baud rate 4800/9600/... /57600, default 115200.

http://www.transystem.com.tw/product.php?b=G&m=pe&cid=4&sid=20&id=85

The default rate is 9600. I found this in the user guide. It seems that the receiver is set at 9600 and the Logger is set at 115200. So what is with all the other baud rates?

Also, would anyone please explain the Selectable Output: GGA, GLL,GSA, GSV, RMC, and VTG

Sorry for all the question. New to this and I am wanting to figure this thing out.
tcassidy
The 1 to 5 are refresh rates. This means the GPS device sends data to the navigation program more than once a second (up to 5 times a second). To be able to fit that information in the data stream, the device needs to talk to the computer at a faster rate (known as baud rate or, really, bit rate) The basic 4800bps baud rate can only carry data fast enough to support a refresh rate of once per second.

The program we know of that can support a faster refresh rate is Mobile PC. Some users have commented on a smoother display but others note the apparent erratic nature of the pointer. It can be advantageous to operators of faster vechicles such as helicopters.

Under normal vehicle navigation situations, 1 HZ update is fine and a 4800 bit rate supports that with no difficulty. The GM2 decided to default to 9600 bps in design which also supports a 1 HZ refresh and could be pushed to 2 Hz.

If you download GPSview from our site, you will see that the GM2 can be set to operate at data rates from 4800 to 115,200 bps and refresh rate to 5 Hz. This is how it is advertised but the version of GPSview included with it does not provide that functionality.

All of this is really moot to most users (including me) as long as the GPS device will support the programs I want to use it with. It can be interesting to those who might want to try the software/ hardware in unusual situations which demand information more often such as travelling at speeds above 100mph for extended periods.

Terry
Ken in Regina
[EDIT: Apologies for some of the overlap with Terry's post. I was still typing this book when he posted his so I missed it. Now that I've typed it all, I'm darned if I'm going to delete any of it. ]

Quote:
Originally Posted by OneRVer
GPSview??? The only change you can make, as far as I can see, is the Hz rate. I assume the when it is set at 1, the receiver scans from 1 to 5. Set to 2, 3, 4, or 5 and you are stuck at that rate. Am I close???
First, terminology. According to Wikipedia:

Quote:
The hertz (symbol: Hz) is the Standard International unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is ... in radio and audio applications.
It's named after the German physicist Heinrich Hertz.

In our case, if your GPS receiver is set to a 1Hz "Fix Update Rate" then once every second it will send all the necessary data for your navigation program to figure out where you are on the face of the planet and plot it on the map display for you to see. Most consumer GPS receivers only have the ability to send once per second so there is no need to be able to adjust this setting.

Devices like the GM-2, and the i.Trek M7 (in USB mode) have the ability to update the location information more than once every second. The GM-2 can send all that data up to five times every second (5Hz) instead of only once every second (1Hz).

So....

Quote:
I do not understand on their web page this, NMEA0183 v3.1 baud rate 4800/9600/... /57600, default 115200.


The default rate is 9600. I found this in the user guide. It seems that the receiver is set at 9600 and the Logger is set at 115200. So what is with all the other baud rates?
Two things here. First, the default "baud" rate ... The GM-2 receivers that Terry and Marvin and I have are all set to a default rate of 115200. That's how they were set when they first started shipping then. They have, since, changed it to 9600 because many navigation programs couldn't do 115200 and all except Streets&Trips can do at least 9600. It looks like someone forgot to change that sentence on their web site. They would probably be happy if you pointed that out to them.

Second, here's what's with all those "baud" rates ... If the "baud" rate is set to 4800, that means only 4800 bits (1s and 0s) can travel from the receiver to the computer every second. If the Fix Update Rate is set to 1Hz, it takes over 96% of those 4800 bits just to send all that data one time. For receivers that only send 1 update per second, 4800 bits per second works just fine.

But if you have a receiver like the GM-2 that can be set to send that data up to 5 times every second, you need to push the bits out much faster.

To get all the bits necessary for sending new location updates 5 times every second (5Hz) you need to set the "baud" rate to 38400. That's 38,400 bits being sent from the receiver to the computer every second. With a Fix Update Rate of 5 new location updates every second (5Hz) and a "baud" rate of 38,400 bits per second, the data will use up roughly 65% of those 38,400 bits every second.

You can set the GM-2 to any of 5 update frequency settings. Each will take more bits in order to send the required number of new location updates each second. Therefore, you need to be able to set the speed at which the receiver communicates with the computer to different "baud" rates to accomodate that, e.g. at least 9600 if you want to do 2Hz, at least 14400 if you want to do 3Hz, and so on.

Quote:
Also, would anyone please explain the Selectable Output: GGA, GLL,GSA, GSV, RMC, and VTG
Those are the prefixes for something called "NMEA sentences". Look here if you are actually interested ... or just want to scare yourself.

NMEA data

Happy hunting....

...ken...
tcassidy
If I recall, the advertising on the iBlue web page is correct. It was the units we received that were wrong!

Terry
OneRVer
I'll tell you what scares me,,,, I think,,,, I am understanding what Terry, Ken and Marvin are telling me. Who said you can't teach an old dog new tricks.



Thank you both.

Terry, I am afraid that if I download your GPSview I would really screw myself up. I am one of those kind of guys that can't keep my hands off of stuff.
laptopgpsworld.com About