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Difficulties getting GPS Fix with older Microsoft USB GPS receiver
lforbes
Just installed Microsoft Streets and Trips 2010 (on my desktop running XP Home) and am continuing to have a problem I had with earlier Streets & Trips versions (which is the main reason I had stopped using Streets & Trips in 2008). The problem is getting GPS lock, or proper lock, when starting Streets & Trips. When I first ran Streets & Trips 2010, the GPS signal finally came up (after about five minutes) but the location shown was out by about 1 Km and the indicated altitude was way low. It stayed that way for about 15 minutes upon which I relaunched Streets & Trips. This time there was no GPS lock at all and Streets & Trips finally timed out and asked if I wanted to continue.

Recalling what I had done in times past, I ran the "SIRF Demo" program, switched to SIRF mode, and everything worked fine. Then switched back to NEMA Mode (@ 4800 baud) and messages from the GPS continued to be received as expected. Then shut off SIRF Demo and returned to Streets & Trips - now it works right off the bat (correct location shown and correct altitude)!

It looks like I have a GPS receiver (it's the one that came with S&T 2007) that is somehow flakey or S&T is not initializing or otherwise not communicating properly with the GPS in some manner.

Was wondering if anyone else has seen this problem and if a fix is available (starting up each time in SIRF Demo b/f moving to S&T is not at all convenient).

BTW, my laptop, also running XP (and using the same GPS), frequently had the same issues. Sometimes it would acquire lock quite quickly, sometimes after a long wait, and sometimes not at all until SIRF Demo was used to fix it.

TIA for any help........
tcassidy
Time to buy a new GPS I think. Sounds like that one is pretty flakey. They aren't tremendously expensive and any newer one such as the BU-353 will be more sensitive than your Pharos 350. It might even work at your desk.

Terry
lforbes
Quote:
Originally Posted by tcassidy
Time to buy a new GPS I think. Sounds like that one is pretty flakey. They aren't tremendously expensive and any newer one such as the BU-353 will be more sensitive than your Pharos 350. It might even work at your desk.

Terry
Thanks for the suggestion - you may well be right about the Pharos being faulty but I do wonder why it works fine (and always has done IIRC) with Sirf Demo but not Streets & Trips. Come to think of it though, it is pretty obvious that the Pharos works well with Sirf Demo in Sirf mode but not so obvious it is working correctly in NMEA mode (nothing much is displayed in NMEA mode, just the comm character stream).

So then, is the BU-353 kind of the receiver of choice on this forum then? What type comes with Streets and Trips 2010 if the package deal (software + receiver) is purchased?
tcassidy
I can't see why your 360 should work in Sirf mode and not NMEA. I am not familiar with the software though. Are you sure it is switching from one mode to the other properly?

The Navation 168 comes standard with S&T 2010. It is a good all around USB GPS receiver and the price is right if you don't already have S&T 2010.

Terry
MisterMoonlight
I have a pharos 500 unit (a little more sensitive than yours). The first startup at a specific spot can usually be very quickly. But in some situations and specific spots, the startup can be very very long. I think that this is caused when the signal is weak i guess. Sometime, just moving position sligthly, and the link time is becoming a little shorter. I have seen 15, 20 mn (and even more) in extreme cases like inside my home to acquire 4 satellites to get a usable link. But at the same difficult spot (i guess it depends about the external temperature conditions?), sometimes it could even not link at all after an hour... In these hard conditions, gps location could be very inaccurate of what i have seen, and the gps lock is lost easily...

Using the same unit in my car facing the sky and it will lock in 1mn (max 2) in most of the cases everywhere, and it is working pretty well...

I suggest you do some tests with another nema tools. Install gpsdiag free tools from the following link:

http://www.laptopgpsworld.com/707-interesting-free-nmea-gps-tools

Then you will have a software that capture NMEA sentences, and displays the signal level of each satellites and the number of them, until you get a stable links. When the link is unstable, you will see in gpsdiag that the used satellites are often changing, or the signal is weak, and that you are using barely 4 satellite with varying signals a lot. Until the gps location (lat/lon) is locked and stable and match your real position. You will also see why the gps lock is lost often in these hard conditions. This will help to see why Streets & Trips behavior is like that.

Suggestion: always use the usb extension cord to plug the unit in your computer...
lforbes
Quote:
Originally Posted by tcassidy
I can't see why your 360 should work in Sirf mode and not NMEA. I am not familiar with the software though. Are you sure it is switching from one mode to the other properly?

The Navation 168 comes standard with S&T 2010. It is a good all around USB GPS receiver and the price is right if you don't already have S&T 2010.

Terry
Firstly, I have the GPS500 model if that has any bearing on the matter. I'm not saying that the NMEA mode is not necessarily working properly in SirfDemo, just that in NMEA mode none of the visuals available in Sirf mode are available (so it's harder to tell in NMEA mode if all is actually well - all you see is the communication strings going back and forth between the GPS and the SirfDemo program).

I don't already have Streets and Trips 2010 so maybe your suggestion of buying the package would be a good plan. In any case, thanks again Terry for the help and suggestions.

Anyhow, the question still remains as to why it doesn't work with Streets & Trips but works in SirfDemo and, works with Streets & Trips after switching from SirfDemo to Streets & Trips (that is what leads me to believe that Streets & Trips is not talking properly to the receiver, at least during power on/start-up).
tcassidy
The Pharos 500 is a good SirfStar III GPS and it would be worth your while to see if you can resolve the issues with it. As MisterMoonlight suggests, you need some better tools to see what is going on in NMEA mode. Either GPSDiag or EarthBridge from the thread he linked would do the job.

Terry
lforbes
Quote:
Originally Posted by MisterMoonlight
I have a pharos 500 unit (a little more sensitive than yours). The first startup at a specific spot can usually be very quickly. But in some situations and specific spots, the startup can be very very long. I think that this is caused when the signal is weak i guess. Sometime, just moving position sligthly, and the link time is becoming a little shorter. I have seen 15, 20 mn (and even more) in extreme cases like inside my home to acquire 4 satellites to get a usable link. But at the same difficult spot (i guess it depends about the external temperature conditions?), sometimes it could even not link at all after an hour... In these hard conditions, gps location could be very inaccurate of what i have seen, and the gps lock is lost easily...
OK, I understand that but the question remains as to why SirfDemo works and Streets & Trips does not (on power up/initialize that is).


Quote:
I suggest you do some tests with another NMEA tools. Install gpsdiag free tools from the following link:

http://www.laptopgpsworld.com/707-interesting-free-nmea-gps-tools

Then you will have a software that capture NMEA sentences, and displays the signal level of each satellites and the number of them, until you get a stable links. When the link is unstable, you will see in gpsdiag that the used satellites are often changing, or the signal is weak, and that you are using barely 4 satellite with varying signals a lot. Until the gps location (lat/lon) is locked and stable and match your real position. You will also see why the gps lock is lost often in these hard conditions. This will help to see why Streets & Trips behavior is like that.
Have downloaded and tried the program (GPSDiag). It seems to have similar functionality to SirfDemo but has the advantage over SirfDemo in that the displays of data work in NMEA mode. If Streets & Trips starts to act up again (I had no problem with it this morning), I will try launching GPSDiag to see if it corrects the Streets & Trips lack of fix.

Quote:
Suggestion: always use the USB extension cord to plug the unit in your computer...
Yes, I do that (and I place the receiver on the window ledge or on the dash close to the windshield).
tcassidy
Others have reported problems with the connections involved with the Pharos 500. I can't recall if it was the USB to extension or between the 2 modules though. You might want to make sure each is clean and firmly joined.

Terry
tcassidy
Quote:
Originally Posted by lforbes
Have downloaded and tried the program (GPSDiag). It seems to have similar functionality to SirfDemo but has the advantage over SirfDemo in that the displays of data work in NMEA mode. If Streets & Trips starts to act up again (I had no problem with it this morning), I will try launching GPSDiag to see if it corrects the Streets & Trips lack of fix.

The diagnostic program is not meant to assist S&T with working with your GPS. It is to give you a clear picture of whether the GPS is actually putting out a clean enough NMEA signal, seeing satellies and acheiving lock. If the GPS can do that, it should work fine with S&T.

Terry
lforbes
Quote:
Originally Posted by tcassidy
The diagnostic program is not meant to assist S&T with working with your GPS.
Yabut my point was that the diagnostic program *seemed* to kick start the GPS into working with Streets & Trips i.e. S&T didn't work, ran SirfDemo, it worked, reran Streets & Trips, now Streets & Trips works


Quote:
It is to give you a clear picture of whether the GPS is actually putting out a clean enough NMEA signal, seeing satellies and acheiving lock. If the GPS can do that, it should work fine with S&T.
Quite true but it was not (on power up) for some unknown reason. I think the solution may be in hand however - refer to response to your previous post.
lforbes
Quote:
Originally Posted by tcassidy
Others have reported problems with the connections involved with the Pharos 500. I can't recall if it was the USB to extension or between the 2 modules though. You might want to make sure each is clean and firmly joined.

Terry
It may be a coincidence but I cleaned the contacts between the two modules (with a pencil eraser) and now it works (GPS with Streets & Trips) every time!

If that turns out to be the permanent solution, thanks much!
MisterMoonlight
lforbes said:

Quote:
Have downloaded and tried the program (GPSDiag). It seems to have similar functionality to SirfDemo but has the advantage over SirfDemo in that the displays of data work in NMEA mode. If Streets & Trips starts to act up again (I had no problem with it this morning), I will try launching GPSDiag to see if it corrects the Streets & Trips lack of fix.
In the same page i have given that shows a link to gpsdiag, there is also a link to "Xport" which is a free nice little tool you may download as well. It allows to split the gps NMEA stream to more than a destination (you may create additionnal virtual com ports to use a gps with more than a software at the same time). For diagnostic, with xport started, you may run gpsdiag and S&T at the same time and compare the behavior of both of them, for gps diagnostic purposes...
Ken in Regina
Quote:
Originally Posted by lforbes
Yabut my point was that the diagnostic program *seemed* to kick start the GPS into working with Streets & Trips i.e. S&T didn't work, ran SirfDemo, it worked, reran Streets & Trips, now Streets & Trips works
It's probably nothing more than the time you've given it to get a lock. It probably would have worked with Streets&Trips if you had simply left it sit for that long, even without running SIRFdemo.

Glad to see you got it working with a better connection. I have a Pharos 500 and, as Terry mentioned, sometimes the connection can get flakey.

...ken...
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