VERY strange problem! Please read.

[nulusios]

I don't use my GPS(es) every day. When I use them I want them to work though, of course.

My hardware data:
- A Nemerix, Haicom HI-305N GPS
- An SS3, Haicom HI-305III GPS
- A GPSmart BT GPS
- A MIO168 SS2 GPS-PDA
- An FSC LOOX 720 PDA

I always have my 720 and my HI-305III in my bag, to be used whenever I need them.

Recently, I needed my GPS, I plugged in CF slot and waited for a fix. No go. In fact the LED flashed fast (faster than when there is a fix), something I had seen in the past with a HI-303III that I sent back to Haicom and Haicom never told me what was wrong with it. Soft reset, removal-reinsertion did nothing. Anyway... I needed it and it didn't work. I went back home and just before I wrote to Haicom, I thought if trying once more. YES! GPS was present this time. I am not sure if I waited for a fix, but I am sure I saw NMEA strings etc. So I thought the problem is gone. Well... up to now, I didn't have this problem again. I just mention it for the full background of the story.

After all this intro, here is the current problem:

Today I needed my GPS once more (duuuh). I inserted it, no "fast blink" just normal steady LED ie. no-fix. Anyway, we started moving, thinking SS3 will get its fix soon anyway (as it did in the past). Well no, in all the trip we made, my GPS software showed something between 0 and 3 sats and NO fix in ANY way for the whole trip. I thought it was a problem with the car screen my friend car has. No. Tried it outside, STILL the same. Open space and yet only 0 to 3 (most usual 2) sats in the GPS info screen.

Now the thing becomes more weird (if you thought you simply diagnose a bad HI-305III). Back at home, I thought of going to my roof and try the "messed up" HI-305III, take along my HI-305N AND the Mio.

After a while cheapo Mio got 8 (yes eight) sats lock. My HI-305III on my 720 got the usual 2 sat, no-fix! Then I removed it and inserted HI-305N (different chipset). Waited (and a bit longer since I didn't expect Nemerix to have the quick fix of SS3)... well you know what? AGAIN THE SAME 2 SAT NO-FIX!!!

??????????????????????????

I tried cold start for both 305III and 305N and it didn't help. What, bad CF slot? No, let me make it EVEN more weird. When I don't use my CF for the GPS, I have a 512MB CF storage card and it works fine. Also in my 305III that has an SD slot on the GPS (! great design) I DO SEE the 1GB SD I have in there FINE!

Give you more details? I also SEE NMEA sentences coming out fine (using appropriate software).

Something even more weird? I have an old "device manager" like software that shows (among other things) the COM ports available and I remember that in the past when I had the GPS inserted in CF slot, I got a COM7 that otherwise was unavailable. Now when I run this device manager program, COM7 is nowhere to be seen, BUT I still can use COM7 to connect to the GPS (although, as I said I never get a fix).

Messed up CF? Messed up registry? But even with messed up CF or registry, the GPS should get its fix anyway (even if I couldn't see it, I would be able to see the blinking "so-I-am-fixed" LED... that never happens, the LED stays on trying to get a fix)... Messed up GPS? What? BOTH? (III and N)

The only experiments I haven't done yet, is to try III and N both with my Haicome 401 bluetooth sleeve and connect them to 720 with that. Also I haven't tried hard-reseting my 720, since this would mean that I would need to re-install some GPS software to check it out.

PLEASE TELL ME YOU CAN UNDERSTAND WHAT IS WRONG!
_________________
NLS

[lbendlin]

GPS is to a large extend statistic (or stochastic if you like that more). The positions of the satellites are an important clue for the receiver to lock on to them. If you keep not using your receivers for longer periods you are invalidating that information (Ephemeris and to a lesser extent Almanac). This is like a factory reset - and if you are driving while the receive is trying to get the Ephemeris downloaded then it can take much longer than the average 12 minutes.

You know when you need your receivers. Give them some slack and switch them on fifteen minutes before you need them, and let them sit in one spot for the data transfer.
_________________
Lutz

Report Map Errors here:
TomTom/TeleAtlas NAVTEQ

[nulusios]

I think I was longer than 15 minutes up on my roof (well I was much more, but I talk about using a single GPS). I will do it again though as I need the positive thinking. I will also try with bluetooth.

I have GPSes for quite a few years and I don't remember this happening before. In fact this "problematic" HI-305III when I firts got it, it made a nice stable lock within 2 minutes after I took it off its box... first time in Greece and probably the last time someone tested it (if ever), was in Taiwan.

I think the problem is more complicated but I really need that positive thinking (as I cannot find something pushing towards SOMETHING to blame).
_________________
NLS

[nulusios]

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