problem - hardware or software

iancjc · Posted: Sun Dec 19, 2004 9:11 am Post subject: problem - hardware or software

Hi

occassionally the gps status screen shows movment when I'm stationary (upto 6 - 7 mph) and also the position arrow sometime darts around all over the place - to roads upto 100 yards either side of the road I'm on.

This doesn't happen all the time last week I drove 200 miles without a problem then suddenly it started. It was operating perfectly for the past 8 months.

The gps is a haicom 303e in the bt slipper with an external antenna (bt hidden away) - could it be the antenna or receiver - when this happens I often have 9 - 12 sats in view!

I've reinstalled 3.07 app and gps but not the map - haven't been out yet to try it - anyone else seen this or any ideas?

Cheers (and merry christmas)

Ian
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TyTn II (WM6.1) / tomtom one v2
TTN6.03 tomtom 7.xx (one)

DavidW · Posted: Sun Dec 19, 2004 3:28 pm Post subject:

I wonder if this is another example of Evermore chipset GPSes behaving a bit strangely.

Make sure the setting in TomTom GPS is NMEA 0183v2 at the appropriate speed so that the software isn't sending any SiRF commands.

Jumping between roads can happen if there's a mistake in the maps where you currently are, or if the GPS is not returning correct data on the direction you're heading. Your position moving around when stationary is not entirely unknown - the errors in a GPS position change over time, though a speed of 6-7mph is a little surprising unless you had a particularly poor quality fix.

David

iancjc · Posted: Sun Dec 19, 2004 6:47 pm Post subject:

David

reloading the software made no difference - neither did replacing the external antenna (I had a spare) so tomorrow will try with my backup gps - globalsat cf and see if that makes a difference.

Also I'm going to leave the 303e unpowered fora couple of days to see if it resets itself.

the speed when stationary isn't due to a poor signal - I was receiving 10 this evening and showing 4mph whilst I was unloading my car!

Could tou expand on the evermore chipset statement - I'm probably going to buy a new bt gps unit this week - not sure whether to get the 303s mmf for the slipper or a sysonchip bt unit or something else - could do without spending more money at the moment but need the gps over the next week (lots of presents to deliver on the night of 24th/25th!) Laughing

Ian
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TyTn II (WM6.1) / tomtom one v2
TTN6.03 tomtom 7.xx (one)

alix776 · Posted: Sun Dec 19, 2004 7:17 pm Post subject:

i see this on a regular basis sometimes it usually happens when the gps signal is week or tt tries to put you on the nearest road and you position to the road is around 50 to 100 meters away from the the road
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currently using aponia truck navigation on windows phone. Good bye IOS don't let the door hit you on the way out .

Oh the joys of being a courier.
device Lumia 950 xl

Eldar · Posted: Sun Dec 19, 2004 8:45 pm Post subject:

iancjc · Posted: Sun Dec 19, 2004 9:50 pm Post subject:

sirf star III when when when????
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TyTn II (WM6.1) / tomtom one v2
TTN6.03 tomtom 7.xx (one)

Eldar · Posted: Mon Dec 20, 2004 4:39 pm Post subject:

Soon, soon, very soon.... You'll be able to get a fix :-) inside a building

iancjc · Posted: Mon Dec 20, 2004 5:45 pm Post subject:

Eldar · Posted: Mon Dec 20, 2004 5:56 pm Post subject:

Ian, I meant inside a house with brick walls and a roof. :-)

DavidW · Posted: Mon Dec 20, 2004 7:06 pm Post subject:

SiRFstar III was announced some while ago, so I'd expect receivers to be out soon. However, I needed a new GPS recently (as someone else took over my old system), so I bought a Fortuna Clip On. That is SiRFstar IIe/LP based, switchable between standard SiRF firmware and XTrac - so you have the best of both worlds.

I believe SiRFstar III is likely to combine the advantages of standard SiRF firmware and XTrac, but it's not available yet.

I can sometimes get an in-building fix with standard SiRF firmware on the Clip On - even more so with XTrac. However don't expect miracles, even with SiRFstar III - you need a signal even though these modern GPSes can use signals far weaker than their predecessors.

David

Eldar · Posted: Mon Dec 20, 2004 11:05 pm Post subject:

Dave, I've seen a Star III demo, it is quite impressive. I cannot give you any figures (like saying it's ten times better than Star II), but it feels like it's way better than Star II.

DavidW · Posted: Tue Dec 21, 2004 4:09 pm Post subject:

I expect SiRFstar III to be another leap forward. I'm sure, in time, once there's product available, there'll be comparative information available.

That said, what's currently available is very good - particularly the Clip On with switchable standard SiRF and XTrac firmware. If you want to buy now, I doubt you'll be disappointed, though if you can hold on (for example if you're looking to upgrade an existing installation to Bluetooth), there's the prospect of SiRFstar III GPS receivers available within the next few months which will be even better than what's currently available.

Certainly SiRFstar III will not obsolete GPS receivers people already have overnight - though I expect within a year equipment based on older SiRF chipsets will be disappearing from the market, not least as I expect SiRF will probably wind down production of the older chipsets. I don't know whether SiRFstar III is pin compatible with SiRFstar IIe/LP, or whether GPS receivers need to be reworked for SiRFstar III.

There will always be developments coming; in a few years' time, we'll have civilian GPS receivers with L2C and L5 support. The US Government have announced that they're intending to augment the existing L1 C/A signal with two new signals which will progressively be introduced as satellites are replaced. One overlays on the existing L2 frequency which is currently only used by the encrypted Precise Positioning Service signal - that one is called L2C. The other is going to use a new frequency, L5, which will be on a frequency inside a protected band for radionavigation use. My understanding is that the L5 development is important for aviation and other safety of life users, as there's much greater international protection for signals in designated radionavigation bands.

There's a fairly straightforward overview of GPS modernisation in this article on the FAA web site.

Another development that will almost certainly come along is dual Navstar (US system) and Galileo (EU system - supposedly now EU / China in collaboration) receivers.

David

Eldar · Posted: Tue Dec 21, 2004 10:17 pm Post subject:

Very thorough, Dave, as per usual. To answer your question StarIII is not pin-for-pin compatible with StarII - as far as I know there is a built-in LNA (i.e. there are two RF amplifiers) and it doesn't require a GPS-specific xtal.

ps4u · Occasional Visitor Joined: Feb 11, 2005 Posts: 1

Hi Dave,

Since your last reply to the qyestion of when the StarIII units will be available was clear back in November 2004, are there any new info on this now?

I understand that the StarIII raises sensitivity from -140 dBm to -159 dBm. That's significant. No wonder Eldar stated that its "way better" . And since I'm looking to use it in an RV with a "cab-over" on rainy days too, I'm anxious to try one.

DavidW · Posted: Sun Feb 20, 2005 6:55 pm Post subject:

There are apparently now a handful of SiRFstar III based Bluetooth GPSes on the market - but I don't have a list to hand, and whether any of them are actually available retail yet, I'm not sure.

The "new" TomTom Bluetooth GPS announced with TomTom Mobile 5 is SiRFstar III based. The technical specifications for it are here - in German, but I'm sure you can make out the key line! I can't find an English version.

However, this GPS is not yet on the market; I believe TomTom Mobile 5 is likely to appear some time in March or April, though I haven't kept up with all the discussion on it.

David

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