Database Develop

GPS position and bad position fix

I have had GPS receivers previously as well as used some, both normal consumer as well as aviation grade GPS systems. Now I have the Kaiser/TyTN II and I am impressed with how sensitive it is! For not losing signal or dropping position I am amazed, good stuff!
BUT ... since it uses so much battery when the GPS is running, I sometimes turn it of for a while, then on later on again. Especially when moving a lot while being turned off (flying or driving), turning it back on can sometimes give problems getting a new fix! Sometimes it gets a fix quickly, but it is hundreds or thousands of miles off. I know it is complicated 3D math for a GPS to aquire its position, and I know it is possible to get a false lock, but the GPS receivers I have tried and had previously never accepted a bad fix.
The unit knows where the satellites are supposed to be, given the time and approximate position, so that is what it assumes. But when it has been off, and then on again and only moved some hundred miles, it can get this false position fix that it cannot get out of easily. If I turn it off again and wait until none of the previous satellites are in view (flying for another hour for instance), it finally realizes it has to start over with a new fix. Older GPS units I used/had often had an option of making a cold start fix (search the sky, autosearch or other names for basically the same thing). It is also sometimes possible to specify or change the last "known" position of the GPS to make it easier for it to get a new fix again. The latter requires that you either can find your rough position in a map or you know a rough lat/lon position.
So, two questions:
1) How do I break a bad fix, tell the unit it is on a wrong path - do a renewed search the sky?
2) How can I change the "previous GPS position" so the GPS unit is forced to assume another position?
I have some GPS applications where you can change the last know position, but it only seems to stay in the program, it is not fed back into the GPS receiver.

No comments here? Must be others with the same problem. Even the oldest, most basic GPS units had an option to enter position manually, or to enforce a new search from scratch. There must at least be some kind of reset function! (NOT hard reset, thanks!)

LGB said:
No comments here? Must be others with the same problem. Even the oldest, most basic GPS units had an option to enter position manually, or to enforce a new search from scratch. There must at least be some kind of reset function! (NOT hard reset, thanks!)
Click to expand...
Click to collapse
I tried google maps and discovered that my actual position was off by some 50 meters from where I actually was. Then I also discovered that in the area I was, if you superimposed the roads on top of the satellite image in Google maps, it was also set off, by about 10 meters only.
Ever since I tried Google maps, my GPS fixes correctly and updates data all the time, but with some programs speed remains 0 and direction remains north even if I move around. After re-flashing the original rom everything is back to normal. Do you know why this happened?

I have got the same problem.
Once after using TrackMe and once after getting my position in Virtual Earth Mobile.
Both times i have used the gps only for a short while and then closed it. On the next start the position has been several hundreds of kilometers off and the speed shows several hundreds kph although I stand still.
Both times the gps has not been ok until the next day.
I have tried to soft reset and also updated the Quick GPS with no result.
I found this thread Kaiser GPS positioning problems which looks a lot like the same.
I have been using the GPS a lot more frequently recently and at first I thought it was these two apps, but now it seem more general. Before I used TomTom on a few occasions with no problem, but then the GPS was on for a longer period.
Anyone else?

GPS cant lock

My gps cant lock without enabling.wireless connections (wifi, 3g). So im asking if someone else is having that problem. Im using 4.1.2 jelly bean

you are not using the gps but its wifi! so i fixed it by:
you can always do the gps antena hack.
i just opened mine and looked for gps contact point
its located above the rear camera.
theres a little coper spring like metal tha conects the main board
to the rear case of the phone.
if you examine it well.
the main reason we cant connect or lock that fast
its because the contact copper is not touching the small antenna on the rear case
that why soldering it or putting some folded paper(easy) bellow that copper spring will fully
push the conntacts between the mobo and ant.
then put it all back in. and try many app for testing gps lock.
i opened mine because its so frustrating that if with0ut this hack gps will lock more than 2-5mins which is b**s***
as i sc it before dou to other problem and they pull my waranty sticker,
so now i can freely open my unit and check things out as well.
now it locks much faster than before. but to tell you
"sgy-young" is way too fast to lock location about 8-15 seconds only!
i fixed my gps, (PLUS!) my:: wifi boost range and network boosted too!
i just solder copper wires inside to do the trick.
so goodluck! and you can do it! no need to use wifi or mobile data.
just pure gps!
it'l be solve, as it solved mine!
goodluck

I dont understand why i have to do this. Why didnt samsung fixed it properly.? So you re telling me that this is a hardware problem. This sucks i dont want to open my phone

Try use "FIX GPS" (google play)

Calibrate accelerometer and/or gyroscope

Hi!
I am facing problems with the orientation sensors (accelerometer and/or gyroscope), because installing several applications to test them (or use games), it is clearly observable, that they are a bit off (with enough to be disturbing when required). For example, games or tests that simulate a ball, and my phone is laying on a horizontal table, the ball rolls quickly to the edge of screen. This happens as well with the built-in tests in the "service menu" of the phone, for accelerometer and gyroscope also.
Do you have any suggestions how could I calibrate these sensors globally (for every app)?
Thanks.

Info
vetko said:
Hi!
I am facing problems with the orientation sensors (accelerometer and/or gyroscope), because installing several applications to test them (or use games), it is clearly observable, that they are a bit off (with enough to be disturbing when required). For example, games or tests that simulate a ball, and my phone is laying on a horizontal table, the ball rolls quickly to the edge of screen. This happens as well with the built-in tests in the "service menu" of the phone, for accelerometer and gyroscope also.
Do you have any suggestions how could I calibrate these sensors globally (for every app)?
Thanks.
Click to expand...
Click to collapse
factory Reset ur phone and then use PC companion app to Repair Firmware...
this can wipe current data and install fresh firmware on ur device
:good:

Hi,
I have the same problem. Only the x axis of the accelerometer seems to be affected : it show a value around 1 instead of 0 while the phone is sitting flat. Y and Z display normal values.
All the software solutions I have tried have had no effect at all... It seems the built-in test reads raw data from the accelerometer. It is hard to imagine how this can be a hardware problem though...
Anyway, in my case I believe a software fix (x=x-1) would do the trick but I have no idea how to do such a thing ! Any help ?
@vekto : Have you solved the issue by any chance ?

Would anyone care to try the accelerometer tests and post their results ?
Typing *#*#7378423#*#* will get you on the service menu. The two significant tests are "accelerometer" and "gyroscope".
I'd post some screenshots myself but I'm not allowed yet...

I'm having the same problem now. It seems one axis is affected. Haven't found a way around so far. This is sad because it affects the images taken with Google Camera Sphere mode. The images are badly aligned together with glitches in between. My phone wasn't like this before.

Either a SW fault - might be able to calibrate with GPS Status & Toolbox app, for example - or a FW fault - and reflashing ROM might help (highly unlikely) - or HW fault - the sensor has moved on the board (which is a bad sign anyway, might be on the way to disconnecting itself).

I sent mine to Xperia Care and got it back with the accelerator fixed. Still unclear if it's a HW problem...
It came back with a white spot on the screen (near the power button) though... so I sent it back again

I'm also having issues with the gyroscope. Installed Bubble app to calibrate the gyro. It showed the gyro was of a couple of degrees. Unfortunately the bubble app calibration doesn't work in a game like Need for Speed. It's very difiicult to achieve good times in the game right now since I have to hold it tilted to the left to go straight ahead.
So if anyone has a fix or workaround... Please do post.

Same problem, Seems after factory reset whith wipe dalvik cache.

any solution?

02nd March 2017, my autorotate has completely stopped working, restart, safe-deposit and reset do not fix. Diagnostics show Gyroscope Light Sensor and accelerometer failed testing, 3 years of same issue, surely there must be a fix that works by now?? ( please note, " turning it off and on again " does not fix it )
Helps Please

I have the same issue. Since last week, gyro, accelerometer, light and proximity sensors stop working. I've tried reflashing stock ROM without success. I have not warranty (almost 3 years old), so I even try to disassemble , disconnect an reconnect every flex (I don't know exactly were the sensors are located on the board). After that I get almost 8 hours of fully functionally sensors and then, they stop working again, so I'm almost sure it's a hardware issue.

Same problem for 3 years
I'm just now getting around to doing something about this. As my power button stopped working I can't post requested screenshot without going to the pc. I have been shopping new (fall 2018) phones after having the Z3+ since release. In my research I'm finding the phone still is better than Samsung, LG, and the pixel3 for me because the 3.5mm phone jack is mandatory for me using my device with an i-rig midi requiring both that port and the USB at the same time. I'm going to do everything I can to keep using this phone till it falls to dust. It's one of 4 Sony I've bought since the day Z1 came out of t-mo. I look forward to testing solutions. :good:

Some time after my post, I bought a new jack/proximity sensor flex and replace it. This solved the issue, but weeks later, the bottom portion of the touch screen becomes unresponsive. May be I have done something wrong... may be programmed obsolescence...

Hi I'm facing a problem of my gyroscope I don't know which one is not working a gyroscope or accelerometer. My gyroscope is so delay when I play pubg mobile and I can't also calibrate my Gsensor it always says FAIL but I put in a perfect flat surface please please please help me with this problems

GPS no fix fixed

Hi everyone just thought I would share my own experience in case it will help anyone. My z started being very erratic with a GPS fix, navigon would lose fix every 15 seconds I used GPS test and it only found 3/4 sats. Flashed other ROM same issue, downgraded to 4.3 same problem. Thought it was hardware so I took of the back and removed the GPS module, on there was two pins that make contact with the GPS module and one was slightly lower than the other, I gently pulled them up so they made good contact with the GPS module, cleaned the contacts on the GPS module put it back together and hey presto almost instant fix on 11/14 sats. I did drop the phone and also had a bad habit of flexing it sometimes also worth mentioning one motherboard screw on the left was fully out when I took the back of. Hope this will help anyone with similar issue.

Anyone having GPS issues?

I have a Note 9 on Sprint, and everytime I go to use Waze, or Gmaps, I do not get a GPS lock. Restarting the phone fixes it, but by the next day, the issue crops up again. Anyone else seeing this?

I too have issues GPS, my. device is constantly loosing its fix. It aquires 20+ Sats very fast, then fix within a few seconds (what is absolutely fine), but a few seconds later it loses the fix for a few moments, fix again, lose again, and this then goes on forever...
I now have the device (512 black Exynos ATO) since a week, but I started to observe this behavior since today!
How is the GPS performance of other users?

Had it happen again today. Went to use Waze, and it would not lock on. Installed GPS Test, and it shows no sats, nothing. Restarting the phone does fix it, but it's a pain. May have to contact Samsung/Sprint.

Done a bit of geocaching and it was spot on the whole time. Also used at work , both trouble. US unlocked 512gb
Sent from my Samsung SM-N960U1 using XDA Labs

Note 9 gpsfix lost
I have the sane issue..i have tey many thinks but i havent locate the source of the problem yet

I had similar issues but it turns out the location method is always set to "phone only", changing back to "high accuracy" fixes it.
Sent from my SM-N960W using Tapatalk

GPS signal is lost in Goolge Maps after update N960FXXU2ARJ1
I have a Note 9 since a few weeks now and it worked perfectly until I installed the latest update (N960FXXU2ARJ1), the one with the fix for the photo quality.
Now when i'm using Google Maps or Waze in my car with Android Auto my GPS loses fix. Google Maps constantly says that the GPS signal is lost.
GPS Status or GPS Essentials show 10 to 15 satellites in seconds with a GPS fix. So GPS seems to work fine. Only when driving the signal is lost.
Maybe there's a bug in the update?

Note 9 on ATT, sporadically it will ask me to turn on high accuracy setting and submit random anonymous data, but it keeps asking me, even when I haven't turned the GPS on. When I hit accept it turns the GPS on, I assume it's the weather widget or something like that needing a location.
My actual issue is I already hit accept and don't want to keep hitting accept and on top of that it will sometimes default to battery saver GPS which is useless.
I dont know how to keep it at either high accuracy or phone only when I go to turn on GPS.

Still having the issue....happened yesterday.

No issues here so far. I'm inside my apartment on the third floor, so sandwiched between apartments. I turned off WiFi to make sure it wasn't using my router. Opened Google Maps and it immediately locked on to me. Right down to what room I'm in.

I still don't know why my gps keeps trying to randomly turn on and asks me to accept or deny, regardless what I choose my GPS turns on without me turning it on.

Same issue here. Losing GPS and the finding a fix again shortly after. Happens in locations with no problem before and changes status rapidly. What's going on?

Looking for this problem in another forums I've discovered that the problem is related with Power Saving Mode in Samsung phones.
Yesterday I disabled the power saving mode and it worked flawlessly through Android Auto, even with the phone at the glove box I had a consistent and precise GPS fix.

ubiquist said:
Same issue here. Losing GPS and the finding a fix again shortly after. Happens in locations with no problem before and changes status rapidly. What's going on?
Click to expand...
Click to collapse
The answer is easier (and more disappointing) than anyone might guess.
The phone simply, has a mediocre GPS unit.
But it's a PREMIUM DEVICE?
Click to expand...
Click to collapse
And? No one cares. OnePlus has been featuring horrible GPS units since forever.
How do you know?! Can I verify?
Click to expand...
Click to collapse
Of course, you can verify. Install GPS Test (or any other GPS app from Store) on two or more phones of yours (including the Note 9, duh) and see the results.
Inside your house, outside, in a car.
So other devices have better GPS?
Click to expand...
Click to collapse
Only Notebookcheck (from what I saw) features GPS reviews, and they don't check all phones.
My experience. (from the phones I tried, owned, had. DB = Dual-Band GPS.)
Note 4: 5/5 || Always worked superb.
Note 9: 3.75/5 || Bit better signal than the 7 Pro, but puts you off by a street or two in the car. It's nothing good/great.
OnePlus 6T: 2/5 || Horrible. Even on a plain street has difficulties.
OnePlus 7 Pro [DB]: 3.5/5 || Not bad, not good. Has trouble finding you in the streets. Works OK until you enter a place with various roads (like an interchange).
HTC 10: 4.5/5 || Good. Stable, solid. Works great really.
Huawei Mate 10 Pro: 5/5 || Perfect.
Huawei P10 Plus: 4/5 || Had some trouble on foot, but okay-ish.
From what I saw, learned:
- Dual-band does NOT matter. If the module is bad, signal will be bad.
- Car glass can block out a good deal of the signal. Heated glass, heat-reflective glass. Ford, for example, uses both on cars. Does not mean it will like reduce signal by a LOT, but will make it worse.
- Phone cases matter. Even thicc plastic cases can reduce signal.
From what I read lately... the following high-end phones have good GPS modules.
- Pixel 3a: Good, thought not flagship SOC/internals/ram/storage. Only 1 camera.
- Huawei Mate 20 Pro: Great phone, albeit bit dated by now. Huawei updates are erratic, support/warranty is horrible. I had huge fights with them, since my family had 4 flagship Huawei devices. Court was always there, legal actions, threats. It's insanely bad. And now they have the Google problem (US vs China), and the phone is 100% locked down, no unlock possible. Unless you buy at external shops - but then you can't get warranty on them.
- Samsung A70: The horrible in-screen fingerprint reader ruins this otherwise perfectly great device.

GPS signal lost a few weeks ago and I tried everything but no signal. Is there anyone who can help with this topic? Galaxy Note 9 - SM-N960FZBDDBT