GPS receivers questions - General Topics

Hi,
Got my new bluetooth gps receiver a couple of days ago and I just have afew questions: It's a QSTARZ BT - Q880
1. It states that this receiver is 32 channel but when i check on tomtom how many sates i'm connected to I have only ever had a max of 8???
2. The gps works fine in the day but i tested at night and it cannot get a signal? I drove around for around 10 mins but still no signal? I doubt if the gps is faulty because it works fine in normal daytime light? I've also had my old ipaq with original wired tomtom receiver next to it and that picked up no problem.
any ideas on the above
cheers

hi
32 channels is just a bit of a gimmick 8 sats is around average for most standard BT receivers , SirfIII receivers due to there superior technology may average 10 or so.
The signal is not affected by light but can be interupted by other atmospheric conditions. When you are trying to get a lock don't drive around as this will just prolong the time to first fix. Also what vechicle are you driving and what is the position of the reciever . Many new cars have Thermic coatings on the windscreen which will lower the incoming GPS signals. When trying to get a fix check the sat screen in tomtom Grey bars indicate a satelite that can be seen but does not have a fix on its location. Blue bars are fixed satelites. you need 3 to get a 3d fix. Also try putting the receiver on the roof to determing if the car or surroundings are affecting signal stength.
If all this fails to shed any light on the problems maybe you have a tempramental reveiver .
Hope this helps
Keep me updated
Fergy

hi mate cheers for the reply. just a quick update i can get a signal indoors now no problem but havent had time to check at night again. I think when i first tested it was just one of them days but so far i'm really happy with it. Just gotta get used to tomtom on a wizard screen insteasd of an ipaq.
cheers

Related

Bluetooth GPS - Very Poor Performance!?

Is it just me/my hardware or is GPS over Bluetooth absolutely rubbish!?
I tried a Holux GR-230 unit first but had the usual problems in getting it connected. When I finally did, I was apalled by it's performance, usually failing to get a gps lock at all.
So I ditched it in favour of a Rikaline GPS-6031-X7. It picked up far mor signals and usually obtained a lock almost instantly. However, it's accuracy is very disappointing. Positional accuracy - it's usually ok on a motorway or dual carriageway but at slower speeds, it jumps all over the place, forwards, backwards, in the middle of fields hundreds of yards away - and that's the worst time for it to happen 'cos it's when you slow down for a junction that you actually need it. The second issue is directional accuracy - it often shows me driving sideways as it's so sloooooow to update/recalc the direction.
If this was my first experience of gps, I might be able to forgive it without a benchmark to judge it against. But I've used Navman with an iPaq, a LAM1 unit with my Nokia 9210 and a (cheap) CF device with my Dell Axim and they all performed far, far better! I know that TomTom Navigator 2 isn't the problem as it performed flawlessly on my Axim (PXA255).
So what's going wrong? Is it the bluetooth devices, or the bluetooth technology, or the XDA II? Will O2's bluetooth update improve matters?
I can no longer rely on this and I'm going to have to start taking map backups - something I've never had to do before and really defeats the object.
Any thoughts, experiences, comments, answers?????
Ged.
I think your problem could be the gps receiver.
I am using the Navman 4400 with my XDAII. It took some time and a couple of patches (from this site, thanks guys) to get it to bond via bluetooth, but now it's setup, it works great. It seems to be very accurate and tells me to exit roundabouts just at the correct time.
It's a bit slow to get the initial fix when first switched on (about 2 minutes) but once connected I have no problems.
Is the gps receiver positioned by a heated screen? If so, this will block the signal and produce the problems you describe.
Have you changed your car? Some newer cars have reflective windshields that can cause problems.
Cheers
Thanks guys. I know of both of the issues you describe but I drive a 3 year old clio 172 - no heated/reflective screen. The receiver usually sits on the dash and receives a very strong signal from upwards of 6 sats.
I've now emailed Rikaline too so we'll see what they come up with (if anything).
I am using the Holux GR-230 and it works flawlessly with towas latest patch 1.0.1.2, a very accurate gps based on my own observations with tomtom2.
Hi guys
I have recently received my new XDA II from Orange (know as SPV M1000)
I am using it with the Fortuna Clip On GPS, Tom Tom Navigator and a Jabra 250 headset.
So far I have had no problems with the GPS, it works every time. On a rare ocasion I have to reset the phone to get the head set to work but this is very rare.
Not sure if orange have modified the software but it all seems to work.
I'm beginning to think that it's the XDA that's at fault. I know TTN2 is ok, you guys aren't having any probs with bluetooth gps devices in general, and I'd have to be extremely unlucky to have TWO faulty gps receivers from different manufacturers!
Persuading O2 that it's faulty is another matter though.
i work in the in car navi business and a 3 year old cleo does have a metalic winscreen apart from the hatched area around the rear view mirror (for use with toll tags and other antennas).You will nead a re-radateing antenna mounted externally to get propper reception as the cleo also has a faradays cage effect making radio reception within the cab area very difficult.(they are a ***** to work on)
pinkslayer, shove it in somebody elses car, or slap it on the roof of yours and see how it go's in that location.
Should know my car a bit better really!
I had tried mounting the Holux in front of the rear view mirror but this didn't help so I didn't bother trying the Rikaline. And my wife has a clio too so no point trying it in hers.
So even though I'm locking on to 5-6 sats, it's still not sufficient!? Or is the metallic screen just causing additional latency?
Its not the number of sats, its the strength of the signal received, I have seen 8 sats showing but tomtom wont attempt a route until the signals are strong enough for a lock,
Rikaline GPS-6031-X7
hi all
i use a Rikaline -x7 with TomTom Navigator 2 on my xda ll with the bluetooth pach from
http://bluetooth.i-networx.de/index_e.html
and the update is slow when taking corners (ie the map is slow to turn to the heads up position) or if you come of a motorway/ dual carriageway thats not on the calulated route it will take some time to acknowledge this
but i do not have the problem of it at slower speeds it jumps all over the place
As for accuracy my old tomtom wired gps was better
but the Rikaline-x7 is usable
Thanks peops. I've now tried mounting it on the rear parcel shelf and also stuck it to the shaded area above the rvm but to no avail (even when it was back on the dash this morning, it took 11 minutes to get a fix and another 5 before it could calc direction - cloudy day!). As soon as it's dry enough, I'll mount it outside the car and see how it is.
I don't really want to do down the re-radateing antenna route as the whole point of having portable equipment is that you can use it anywhere and in any vehicle.
Im using the Rikaline GPS 6031-X7 and Im really happy with, no problems at all in fact I think its brilliant............
I'm using the fortuna clipon in a landy with heated windscreen. It doesn't seem to affect the signal (with or without the screen on) and I have to say i was expecting problems with it. It has been the only thing about the whole BT GPS/XDAII setup that I haven't had problems with..
Technology eh!

GPS receiver upgrade or to buy Tytn II

Dear All,
before to buy a Tytn II, I'd like to understand if the GPS comes upgraded by the future's ROMs (I think yes) or is necessary a future hardware change ???
P.S.:
I have a Tytn with the GPS Fortuna ClipOn BT, and I don't know is better to change the GPS receiver or buy the new one with GPS included.
Thanks a lot
Ciao ...
ritmia said:
Dear All,
before to buy a Tytn II, I'd like to understand if the GPS comes upgraded by the future's ROMs (I think yes) or is necessary a future hardware change ???
P.S.:
I have a Tytn with the GPS Fortuna ClipOn BT, and I don't know is better to change the GPS receiver or buy the new one with GPS included.
Thanks a lot
Ciao ...
Click to expand...
Click to collapse
Buy the new phone - its worth it. The GPS works fine & the phone has a lot more oomph (CPU memory etc)
Seconded, get the Kaiser and off load your BT gps. My Wizard is now relegated to my wifes car with my old BT gps and that is her SatNav solution. I am well happy just having the Kaiser as the gps works as well if not better, and I only have to carry one device around.
Had a bluetooth GPS unit connected to my AXIM as my GPS system before I bought this phone.
My AXIM crashed, battery died flat dead, so I had to use my phone as backup. Used the built-in GPS with TOMTOM on my Kaiser and it was AWESOME- worked perfectly!
Get this phone you won't need anything to supplement it what-so-ever...
No. The Kaiser built-in GPS chipset can't compare to BT-359 SIRF III. It sees less Satellite; also, many of them are invalid signal, that means these satellites were grey. With the ones are blue, the signal keeps going up and down. Sometimes, for somewhat reasons, Kaiser loose the GPS fix (you see the map turn around) even in the clear view sky, then you loose your current position.
If you're driving in the crowed sky area (e.g NYC), stick with bluetooth GPS SIRF III chipset receiver.
Read more here: http://forum.xda-developers.com/showthread.php?t=339257 I had used the BT-338 then upgraded to BT -359 which is slimmer, sleeker but lack of external antenna connector and less of batt. time life.
i have tomtom - works faster.
tilt gps - far worse. but it works at 95%.
ritmia said:
Dear All,
before to buy a Tytn II, I'd like to understand if the GPS comes upgraded by the future's ROMs (I think yes) or is necessary a future hardware change ???
P.S.:
I have a Tytn with the GPS Fortuna ClipOn BT, and I don't know is better to change the GPS receiver or buy the new one with GPS included.
Thanks a lot
Ciao ...
Click to expand...
Click to collapse
Frankly I doubt the inbuilt GPS is going to be as good as an external one. (I reserve my judgement till my Tytn II arrives. However, your decision should be based on expense too. Do you mind spending out the extra for inbuilt GPS by buying a whole new Smartphone?
If yes then no problem because you can still use an external gps. If you want to keep the cost down get an external one. I bought an i-blue 737. The device cost me 30UKP and it's never ceased to amaze me how good it is. This will pick up 7 satelites anywhere in my home regardless of where I am. No need to go near a window, the acuracy is astounding with WAAS + EGNOs enabled and 115000 baud coms.
As I say I doubt the inbuilt one is going to match this but it probably will be fairly decent.
Disclaimer: this is just my opinion.
Nghiem said:
No. The Kaiser built-in GPS chipset can't compare to BT-359 SIRF III. It sees less Satellite; also, many of them are invalid signal, that means these satellites were grey.
Click to expand...
Click to collapse
True for the reception quality, but not for the TTFF which is much shorter with the QualCOMM chipset than with a Sirf III (less than 5 seconds in most cases).
The degradation of the signal due to obstruction (when inside a car for example) is virtually identical to a Sirf III chipset.
The only real weakness with the QualCOMM chipset for the time being is that it has major problems getting a fix when moving quickly. I tried several times to get a fix while moving with ~450mph with a clear view to almost all satellites and the QualCOMM has a very hard time to find more than 2-3 useable satellites. Even after 5-10 minutes no useable position can be determined. Moving quickly to get a fix should not be a problem at all for any GPS chipset.
But I have high hopes that those "quirks" will get fixed with a future firmware update.
The Kaiser has an antenna port specifically for the GPS undeneath the battery cover. I don't know if a battery cover can be found that exposed it more gracefully but I imagine with a small antenna would augment the signal nicely.
That being said, without using an external antenna, I'm actually quite impressed with the accuracy. I wouldn't have anything to compare against it but it's always been dead on for me.
I use TomTom 6 but I've played with google maps and Windows Live Search.
I have noticed it can take a long time to get the first lock on occasion, and especially so when driving at speed. Not really a problem for me, as you usually plan where I'm going while the car is stopped.
-James
Since GPS works with as little as 3 sats, and 4 for 3D positioning, why does everyone worry about getting 7 tuned in? Seems a bit anal to me.
The Kaiser GPS IMHO is a tad slow to init, but other than that, it's worth every penny to not have 2 devices to handle at times. I've never had a problem loosing connectivity, so I'm 100% satisfied with the Kaiser. YMMV of course.
Now if HTC would use a decent CMOS sensor in the camera, then I'd call the phone perfect. But that's another thread...
Dear All,
thanks to everybody about the answers ... I think I'll upgrade my GPS receiver (is more cheap). In this moment, I wait other tests about the GPS of Tytn II.
Ciao, ...
scottwilkins said:
Since GPS works with as little as 3 sats, and 4 for 3D positioning, why does everyone worry about getting 7 tuned in?
Click to expand...
Click to collapse
Because the more satellites you are evaluating, the more precise the position gets and in case you lose track of one of the satellites, you will still be shown a valid position.
Adding to that, the RAIM functionality of GPS receivers for an even more precise position while getting rid of most common GPS erros only works with 5 satellites or more.
So, while it's true that you only need 3 satellites for an 2D position, this fix will not be very precise (due to lack of crosschecking with other satellites and typical GPS calculation errors which happen all the time) and you will lose your position as soon as one satellite disappears from your view.
However GPS receivers which can track more than 12 satellites at any given times are useless because there will never more than 12 satellites visible at any specific point of the earth, most of time you can only track and use a maximum of 8 satellites simultaneously.
vacsed said:
I tried several times to get a fix while moving with ~450mph with a clear view to almost all satellites and the QualCOMM has a very hard time to find more than 2-3 useable satellites.
Click to expand...
Click to collapse
Doesn't your F15 eagle have built in sat nav?

[Q] Is my GPS chip defective ?

Hello,
I'm encountering some issues with my Samsung Nexus S GPS. I got the i9023 (Europe/SLCD) version of the phone, which is running default rom (stock), freshly updated to 2.3.4 (via official OTA!).
I couldn't figure why, when using Maps, my position would usually be around 1 km away from where I am. I found out later, this time using Navigation, that it is desperately searching for a GPS signal, that it can't find. Sometimes I manage to get a lock, when I keep it running for like 30 - 40 mins, but it immediately disappears. GPS Statuts keeps showing 0/5 sats.
I was convinced that my GPS chip was defective.
But today, I was hanging out in the city and tried running Navigation. I got a lock, for the first time, within a 15 sec delay. That was the first time that I managed to get live GPS tracking. I've walked a bit around, and the tracking was really, really accurate.
Back home, in my apartment, again I can't get any signal. I live in the 3rd floor, walls aren't that thick and, as for an anecdote, in the same room, my iPhone 3Gs instantly finds my position.
I've bought this phone 6 days ago and therefore still under warranty. Question is, can we say my GPS chip is defective ? Is it worth requesting a replacement ?
Thanks !
1st) You cannot expect to get gps reception inside even with professional equipment. When your iPhone gets a fast fix it's most likely WLAN triangulation. As Apple uses a different database than Google, it may work on on your iPhone and not on your Nexus for a paticular place and vice versa.
2nd) It's unlikely that your gps is broken if you can connect to GSM/UMTS/CDMA2000 networks as gps is processed using the same chipset.
3rd) That 1km-off-fix might be celltower based location, 1km sounds quite plausible.
4th) Try _NOT_ to move until you get GPS fix.
5th) Keep internet access while trying to get a fix. The Nexus S as most phones on the market use assisted gps, where your phone contacts a server that provides data which enables your phone to track its position more easily.
6th) Good luck.
Yes, well, I had 2 friends which came to my place, in my room, and just activated GPS on their iphones and it located them straight away, to our exact position. So it was definitely the GPS tracking and not triangulation.
Indeed, when MY phone locates me off 1 km, this is definitely triangulation or cell-towers.
Of course, when I try to get a fix in my apartment or on my balcony, I just put it on a table and must wait for at least 30 mins to get a lock, and it disappears quickly. Doesn't seem normal to me ...
Finally to answer your 5th point, I got 3G, so a perfect fast & smooth inet connection.
GPS testing should always be done outside, you are not supposed to use it indoors.
What is probably happening there is that the other devices are more sensitive and can still get a lock. You might be able to get a lock if you place your phone very close to the window.
I got a Nexus S recently and noticed that the GPS is quite weaker than the one on my old HTC.
Although the Nexus is faster to get a lock (if you let it use 3G) the GPS itself is less sensitive and accurate.
It looses signal easier, for instance, if i go under some trees, and it takes more time to get signal back after loosing it, for example, if you go under a bridge, the old HTC would get the lock back in 2 seconds after leaving the bridge, the Nexus took half a minute.
Having said that, i think it's good enough for driving navigation, i have done some tests and on the road it behaves well enough.
You shouldn't be surprised, this phone is very similar to the Galaxy S and that had terrible GPS issues, this nexus is better, but still weak.
Thank you for your feedback, temp9300 !
I guess the Nexus S can't compete with iphone's. But it's ok, as long as it works fine outdoors, this is what matters.

[i9003]GPS under cloudy sky not locking at all.

Since I bought i9003 phone this is my 1st rainy season hence cloudy & last few days I am not able to get gps signal at all, it just refuses to lock on as hardly 2 satellites are visible with poor signal.
I traveled 2hrs on road with angled sunlight but under heavy cloud (overhead) cover today & gps refused to lock.
Is there a a way out or our phone gps is useless under cloud cover, I am wondering what happens under dense fog which we face in winters?
Does that happens to dedicated CAR GPS too?
At this weekend I traveled under storm clouds and GPS worked well. May be because I did the following:
1. With help of GPS Aids I took LTO data
2. Before going by car I stay while GPS was taking signals.
Then I was going for more then 300 km without GPS loosing.
I noticed with Nokia 5800 that taking position in moving car is harder than when you are staying.
Sent from my GT-I9003
Strange mine is not working past few days now since we have monsoon clouds or may be some hardware problem has occurred need to test it thoroughly.

[Q] what about the gps

Hi !
I have a desire s and the acuracy of the gps is sometimes awfull.
With gps test it sometimes give me a precision of 6m and sometime of 80m what is a big problem when your driving a in a big city where the is 3 or for road side by side.
If somebody can make some test with the gps precision of the one s.
I would apreciate it.
Thanks in advance.
a) Where is the phone located in the car when driving?
b) Have you downloaded some GPS Toolbox that gives you a clear overview of how many satellites are in view? Especially IN CITIES the line of sight to the sky varies a lot and can often obscure satellite fixes when being jammed between high rise buildings.
c) Do you have the most current radio firmware (I believe this one contains the GPS stack also).
As I rely on navigations by phone a lot too I will be happy to give you results once my One S comes in, however I can only compare to my current Sensation which has never given me any problems.
Also note that some types of cars have a coating on the windscreen that screws with GPS reception, so if you have a high end vehicle with an expensive optional windscreen this might be the cause (although unlikely, people driving those cars with those options usually have onboard satnav).
My car is from 2004, and I did not have any problem with my htc hd mini and my touch cruise before. same car holder on the windscreen.
And I already have flash lastest htc stock rom ans lastest radio, it 'sa bit better than the bouygues telecom rom and radio that came with the phone but last time in paris the gps was lost during 15mn hopfully a friend had a htc hd2.
Your feedback will be apreciated.
Thanks
Hi, I've had the same problem with a Desire HD Gps. It took ages to fix or accuracy was terrible. One S Gps receiver is way better than that. I takes seconds to fix even at home (old one only worked when placed in the window).
As promised I have just sampled the GPS of the One S and the Sensation side to side (I used a MyTracks recording while they were both in my rear jeans pockets when walking the dog).
The routes have only minimal differences. Initial GPS acquisition on the One S was a bit slower than on the Sensation, but I credit that to needing to get a "fix" while the Sensation already has one (and the GPS satellite manifest) for my area cause I use it regularly. It was the first time GPS was ever turned on on that phone so a little delay is understandable.
No difference to be measured, both OK. will update once I actually use the One X with CoPilot Nav Software in a crowded city with high rise buildings etc. that block the view but I expect the same performance that I got from the Sensation.
Maybe this helps.
thanks
I have passed my order today

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