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Testing three USB GPS receivers
Ken in Regina
I'm fighting a summer cold right now so a couple of days ago I was sitting watching a golf tournament on TV instead of being out on the golf course. Watching a golf match is not something that will occupy 100% of your attention no matter how big a golf nut you are so I decided to do something I've been meaning to do for awhile.

I have three USB GPS receivers - GlobalSat BU353 and two Microsoft receivers: the older Pharos 500 and the newer Navation 168 stick. I've never actually tested them one after the other in the same place to see if there are any noticable differences in their performance.

I set up my Acer netbook on the arm of the couch and began testing. First I just ran each one of the receivers until they had a 3D fix. I had not used two of them for nearly a month and the Navation (u-Blox 5) stick had not been used for a lot longer. This first run for each was just to get them past a cold start, which is usually necessary when a receiver has not been used for quite awhile.

Once all of the receivers had a chance to get a 3D lock I started the cycle over again, plugging each one in and waiting to see how long it took to get a 3D lock, how many satellites it could see at the time it got the lock and how many satellites it would eventually pick up if I left it running for 10 or 15 minutes.

I did this cycle three times for each receiver, switching from one receiver to the next on each cycle.

GlobalSat Bu353 - Quick to get a fix and always had at least 5 satellites when it achieved the 3D lock. After sitting for a few minutes it would be seeing as many as 8 to 11 satellites. (Note: this will change more or less constantly with any receiver as the satellites move in the sky and the constellation that is visible to the receiver changes.)

(Microsoft) Pharos 500 (came with Streets&Trips 2008) - Quick to get a fix and always had at least 5 satellites when it achieved 3D lock. After sitting for a few minutes it would see as many as 9 to 12 satellites.

(Microsoft) Navation 168 (aka u-Blox 5) (sold with Streets&Trips 2009) - Noticably slower than the other two to achieve a 3D lock. Never had more than 4 satellites at 3D lock. Sometimes it sat at 3 satellites and a 2D lock for a minute or so before finally getting a 3D lock and another satellite or two (the other two generally go straight to a 3D lock directly). After sitting for a few minutes it would see 6 to 8 satellites.

The GlobalSat BU353 was rock solid through the testing with no difficulties and generally a dead heat for performance with the Pharos 500.

My Pharos 500 has always had a rather flakey USB connector. It's performance is excellent but I need to be careful about the cable connection or I lose it easily. I have heard reports of other people having similar problems. It's not a huge issue but something I need to be aware of when I'm setting it up. Considering I got S&T 2008 AND the receiver for the same price as a GlobalSat BU353, the Pharos 500 was a steal.

The Navation 168 is okay but didn't perform as well as the other two. I don't know if it's the sensitivity of the GPS chipset in it or the antenna. It's really picky about how it's positioned. Small changes in it's position make a noticable difference in how it performs. This suggests that the antenna is probably the culprit.

Because of the shape of the Navation receiver and the thickness and stiffness of the cable it comes with, it is not always easy to get the Navation into an optimum position so that it will stay there. Unless you are prepared to tape the receiver or the cable into the position you want, you are pretty much at the mercy of that thick stiff cable. I have had much better success using the nice flexible cable that comes with the Pharos 500 on the Navation stick. (On the other hand, because of its shape, the Pharos 500 can be placed in a good position and is much more likely to stay put even with that stiff Navation cable.)

Both the Pharos and the Navation are indoor units. The GlobalSat will work nicely outside on the fender or the roof. It has an integral cable, is well weatherproofed and has a magnet that will hold onto steel in a gale force wind.

It should be noted that this is a sample of only one of each receiver so I can't guarantee that mine are perfect examples of each model.

It was a poor substitute for golfing on a lovely afternoon but it satisfied my curiousity and hopefully it will also be useful for someone else.

...ken...
Ken in Regina
People using the Pharos 500 or Navation 168 receivers will be tempted to plug them straight into their laptops or netbooks rather than use the USB cable that comes with them.

We have some reports that people are having troubles with them that are usually resolved by using the cable and getting them some distance away from the computer.

While I was testing the three USB receivers I decided to test this out as well.

With the receivers plugged directly into the Acer netbook, without relocating the netbook from where it had been sitting through the previous testing, the performance was reduced considerably. The Navation, in particular, had real difficulty getting a location lock. With this part of the test, the receivers were in a different location than for the previous testing. So...

I then moved the netbook so that when the receiver was plugged directly into its USB port the receiver was approximately in the same location as it had been when testing with the cables. The performance was still worse than when using the cables.

The Pharos 500, which had previously been able to see anywhere from 9 to 12 satellites after sitting for awhile, was never able to see more than 6 or 7. The signal strength for all satellites in sight was lower across the board.

The Navation 168, which had previously been able to see 6 to 8 satellites if left for a few minutes, never saw more than 4 or 5 and sometimes would drop back to a 2D lock.

In both cases it was obvious that plugging the Pharos 500 and the Navation 168 directly into the computer USB port hampers the performance a lot.

Using the cable that somes with each unit allows for positioning of the receiver in the best location while still placing the laptop or netbook in a convenient location. (Using a Bluetooth wireless receiver provides even more flexibility for receiver and computer positioning independently from each other.)

It's possible that some computers will produce enough electrical interference that the receivers will not work at all when plugged directly into the computer's USB port. I did not have that problem with the Acer Aspire One netbook.

...ken...
Ken in Regina
I have Garmin Mobile PC, iNav iGuidance, Microsoft Mappoint, and Geolife Navmii installed on my netbook. In preparation for the receiver performance testing I decided to see which one would be the easiest to do the testing with. Here's what I discovered.

Each of the three receivers present themselves on different virtual COM ports even when plugged into the same USB port.

When switching receivers for the testing, all of the nav programs required me to run through the menus to reconfigure the GPS port setting.

Except Garmin's Mobile PC!

I have always liked the way Mobile PC is able to automatically find a GPS no matter what type or how it's connected. I gained a new respect for Garmins autodetection routines with this testing.

I started Mobile PC and began the testing, switching receivers after I had seen what I wanted to see on each cycle of each receiver. Through nine receiver changes for the initial testing and at least another half dozen changes as I tested the two Microsoft receivers with and without the cable connected, I never had to exit Mobile PC. And I never had to mess with the GPS configuration settings. Not once!!

Mobile PC would do a little hunting each time I unplugged one receiver and plugged in the next. But it never took more than 15 or 20 seconds for it to find the next receiver and start displaying the GPS info.

Now that's performance!!!

Garmin Mobile PC's GPS autodetection performance through this testing was impressive enough that I thought it was worth mentioning.

...ken...
tcassidy
IGuidance GPS autodetect was good with version 4. It could give a list of GPS devices attached and let you choose. I find the autodetect in iGuidance 2009 useless.

I think Mobile PC is not as good at switching GPS devices as it was. However, my experience was switching between serial and BT. I stick with v30 on my UMPC for this reason.

Terry
Ken in Regina
That's interesting. I wasn't aware iGuidance even had autodetect. With all the testing I've done with it over the past months it's never found whatever GPS device I have connected. I've always had to configure it manually. I've only ever used the 2009 version.

I used Mobile PC 5.00.60 for this testing. I only switched between USB devices. I didn't try switching from USB to Bluetooth or vice versa. Something for a future test when I'm bored and looking for something to waste time.

...ken...
tcassidy
iGuidance 2009 Autodetect is under Tools-GPS Info.

If you don't have the BT dongle attached, GMPC will not even look for BT devices.

BTW, I had to break out the BT keyboard for this screen shot. When I select PrtScr using Synergy, the Tools dropdown closes.

Terry
Attached Images
autodetect.jpg  
tcassidy
iGuidance detected 2 BT GPS devices when I tried it. It found COM5 (10x) and COM6 (Holux) but the display made it impossible to choose which I wanted. I thought the problem was the 800x480 display so tried again at 1024x600 and got the same results. When I selected OK, iGuidance started using a GPS but I didn't know which one. Now I can't remember if v4 let you choose or not. Further testing required.

Plug in all your USB GPS and see what happens!

Terry
Attached Images
autodetect-working.jpg  
tcassidy
My memory has failed me again. v4 worked exactly the same way, listing the detected GPS but not allowing a choice. I suppose this is a reasonable approach as you would only expect one GPS anyway. However, I have experienced problems with 2009 ability to autodetect.

I took a long time with this as the Toshiba laptop suffered a brain fart and wouldn't talk to the network. Eventually, directing it to a different router resolved the issue but that is one area where Vista is way better than XP (from my experience anyway). I liked networking a lot better before IP addresses though.

Terry
Attached Images
autodetect-v4.jpg  
Ken in Regina
Quote:
Originally Posted by tcassidy
iGuidance 2009 Autodetect is under Tools-GPS Info.
That's not autodetect!!! What does it help me if I have to go through the menus in just as many steps to "autodetect" a device as I need to go through to configure it manually???

If you don't know about that menu selection (I didn't) and have never stumbled across it, if the GPS is not already on the port that iGuidance is set to, it just sits there like a lump. No hints, no help, nuthin...

The reason I was so impressed with Mobile PC's autodetect is that you plug in a GPS, run Mobile PC, it finds the GPS all by itself and starts to use it. You unplug the GPS and plug in a different one, it finds it all by itself and starts using it. No menus, no restarts, no nuthin'....

That's autodetect.

In my opinion.

...ken...
Ken in Regina
Quote:
Originally Posted by tcassidy
If you don't have the BT dongle attached, GMPC will not even look for BT devices.
Of course not. That's exactly what you would expect from well-designed, well-behaved software. If the Bluetooth dongle is not plugged in, the Bluetooth stack is not active. Nothing to do. Mobile PC sees this and wastes no more time on it. Exactly the way it should be.

Well, exactly what I would expect, anyway.

...ken...
tcassidy
That was not meant as a negative comment. The problem I see with the later implementations of GMPC is they can't seem to decide where to look first (assuming BT is available). At startup, it may be 'attached' or BT and sometimes a restart or two is necessary to get it to change. Using Disable and pointing to where you want it to look often does not work.

Terry
Marvin Hlavac
Nice comparison of the three USB GPS receivers! This was done indoor, in your house, wasn't it? A few years back, with older GPS technology, that might have not been possible. GPS receivers were less sensitive, and you would have difficulty getting any 3D fix.

In my experience the new u-Blox 5-based unit is not as sensitive as the other two, just like you said. It's likely due to the smaller size of the internal antenna. Yet, I would buy it over the GPS-500 unit just because of the issues with the bad mechanical design of the adapter/connector/USB plug. The new Microsoft unit has been designed better, and I don't think we will be hearing from users who damaged it, unlike the old unit.

I've been using the new Microsoft USB GPS "Locator", Navation 168, with u-Blox 5 chip, for several weeks weeks now, since my BU-353 failed, and it works just fine. It sits on my dash board, and I use a USB extension between it and my laptop. The only thing to add is that the Microsoft logo must face up, towards the sky, for it to perform better.
RsH
I would add that the Mobile Action I-gotU GT-120 serves as both a GPS receiver that works with Streets and Trips, MapPoint and Street Atlas AND an independent GPS recorder that will retain up to 65000 points in its flash memory, and run over 60 hours if you record once or twice per minute. At one point per second it will retain 36000 points before it runs out of power, according to Mobile Action. It weighs 20 grams, and is covered separately in my review, now updated. In Streets and Trips you will see Latitude, Longitude, and Elevation if you use it as a GPS receiver. Speed will be shown by Streets and Trips, as usual when using a GPS receiver.
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