Develop Bugs

Quick GPS needed to make Tom Tom work each time??

HTC Touch HD Seems to have a problem with the way this device is handling GPS.
I have Tom Tom 7 installed and when I try to use Tom Tom 7 it looks for a valid GPS signal and then shows "No GPS Device" It will then find a valid signal and then again shows "No GPS Device" this changes every 10 or 20 seconds.......
If I use quick GPS first before I start Tom Tom (even though Quick GPS hadn't expired) it works fine!!!
Confused!!!
Please help!
Thank you

bit odd, mines fine, the only thing that is probably different is i turned off A-GPS, try turning that off, im assuming you havent been playing with its settings?
try a different GPS enabled program and see if that has the same issues.

dazza9075 said:
bit odd, mines fine, the only thing that is probably different is i turned off A-GPS, try turning that off, im assuming you havent been playing with its settings?
try a different GPS enabled program and see if that has the same issues.
Click to expand...
Click to collapse
I have turned A-GPS off and it has locked on almost immediately and seems to be keeping the signal so far - There's a first!
I'll give it a bit of a test drive tomorrow and keep my fingers crossed...
Can you give me a quick understanding of how A-GPS is supposed to work (or not)
Thank you for your help.

Andy-- said:
Can you give me a quick understanding of how A-GPS is supposed to work (or not)
Click to expand...
Click to collapse
It's supposed to logon to a server provided by your ISP, then use celltower co-ordinates to help make GPS more accurate.
It's basically totally broken on the HD.

To get a fix the GPS receiver needs Ephemeris data. This can be acquired in several ways.
1. Direct from the satellites to the GPS receiver.
2. From a data file (QuickGPS).
3. Transmitted from a cell tower (AGPS).
1. The receiver will get a fix without any assistance but will take a while to acquire sufficient data from at least three satellites to do so.
2. The receiver has much of the positioning data stored in a file so will resolve a fix quickly.
3. The data transmitted from the cell tower will take time to be received so will take slightly longer than 2.
If both (2) and (3) are supplying Ephemeris data, then that data may be similar but not identical. At this point the receiver will have a WTF moment while trying to resolve the fix from differing data, and so will rely more on (1).
Throw into the mix a weak cell signal and possibly a weak GPS signal / reflections and the problem is compounded.
Clearly there is no need for all three, and in many cases it is problematic. Keep the QuickGPS data up to date and switch off the AGPS.

Fully understood,, thanks for making it so understandable.

I dont believe A-GPS has anything to do with it, and I have mine always disabled to avoid any potential network charges for using it.
I did have some initial teething problems with getting GPs working but once I got up-to-date s/w and configured everything correctly, things improved dramatically.
Now GPS synchronisation is usually very quick indeed, with lots of satellites visible. Occasionally it wont synchronise but I find a soft reset of the device always puts this right.

gotta love that WTF moment wen it spazzs out.

Google Maps 4.0 Unable to locate Satellites

I have downloaded the 4.0 update. Now I get a Weak GPS signal alert after it searches for roughly 10 minutes.
I have tried all Com0-9 ports, hard resets, and uninstalling/reinstalling Google Maps 4.0
I have the US Cellular HTC Touch Pro 2, WM 6.5 pro, running the standard ROM.
Is this a HTC hardware issue, Google Maps issue, or USCC tower issues??
I had no problem finding 8 - 10 satellites with the old version.

Using my Tilt2 with stock ROM, Google Maps 4.0 got a fix for me.

GPS is a piece of garbage for this phone, at least for me,
It just never worked again for me since the stock rom (always says seeking satellites 0)
Alos,
"My location" is always is in the same spot (I can be miles away and says i'm in the same place)
I haven't done any research on this two issues, maybe some has my problems too?

Well maybe you should try this.
After I flash a new rom to get gps to work I have to do this.
Run "htcGPStool"
Leave phone outside for about 3-5mins until it gets a lock. After that my gps locks in 30seconds or less
ps, the baud rate for the tilt 2 is 57600- com 4

try the link in my signature for the aGPS cab.
This enables aGPS and changes the servers from the public ones which are configured on HTC (and many other devices) by default to the nokia ones which are maintained better and lead to a faster lock.
After installing the cab, run and update/download QuickGPS and make sure you have a data connection enabled then either try google again or htcGPStool or any other gps utility and see how fast you get a lock then
initial lock might take up to a minute, but locks after that come almost instantly.

fone_fanatic said:
make sure you have a data connection enabled
Click to expand...
Click to collapse
Why does one need a data connection for GPS? OK, for Google Maps, yes, but just getting a fix doesn't require one -- or does your CAB do something that /does/ require a data connection?

A while ago I read people enabling bluetooth to get GPS working. Yesterday I disabled the cellular phone and it looked like GPS was locking after this. Not a fix if you ask me anyways...

pistou said:
Why does one need a data connection for GPS? OK, for Google Maps, yes, but just getting a fix doesn't require one -- or does your CAB do something that /does/ require a data connection?
Click to expand...
Click to collapse
you need a data connection for aGPS. GPS itself does not need one, but the a in aGPS stands for assisted where it uses your data connection to connect to a server to locate you more precisely.
(My understanding of this is that basically your device sends info to the server about which cell site towers are near you, the server uses this info to tell your device which satellites are best for your location, so your device isn't just looking for every sat. its looking for specific ones.)
Here's the wiki for aGPS
http://en.wikipedia.org/wiki/Assisted_GPS
Theres also a bunch of websites with more info regarding aGPS but its best to have your data connection enabled if you want to use aGPS.

gotwake424 said:
Well maybe you should try this.
After I flash a new rom to get gps to work I have to do this.
Run "htcGPStool"
Leave phone outside for about 3-5mins until it gets a lock. After that my gps locks in 30seconds or less
ps, the baud rate for the tilt 2 is 57600- com 4
Click to expand...
Click to collapse
Is "htcGPStool" QuickGPS on the programs list?? If not, explain thank you. As for the baud rate, etc... are you talking about the GPS hardware port? My settings say (none) and Baud rate: 4800???? This I have never messed with, could this be the problem??

ATT Tilt 2 w/ stock ROM...Loaded google 4.0 today with no connectivity issues. I normally able to locked my GPS signal in seconds.....

dataylor said:
Is "htcGPStool" QuickGPS on the programs list?? If not, explain thank you.
Click to expand...
Click to collapse
No, "HTC gps tool" is not the same as QuickGPS and it doesn't do the same thing.
AFAIK, QuickGPS talks to a server and gets info on where/what satellites should be visible for your location, your location determined from triangulation (or some kind of location) of nearby cell towers.
HTCGPStool uses the GPS functionality of your phone in some way that helps subsequent lock on satellites. Honestly, I don't know exactly what/how it does -- but it's not the same as Quick GPS.

MCbrian said:
No, "HTC gps tool" is not the same as QuickGPS and it doesn't do the same thing.
Click to expand...
Click to collapse
Ok, where is htcGPStool??? Looked through the settings and have not found anything that directs me to HTC gps tool.
I have an "external GPS" icon that directs me to GPS settings allowing me to change GPS program ports, and the GPS hardware ports.

Brodie619 said:
ATT Tilt 2 w/ stock ROM...Loaded google 4.0 today with no connectivity issues. I normally able to locked my GPS signal in seconds.....
Click to expand...
Click to collapse
awesome, It locates me just find just doesn't find any satellites. Then I get Weak GPS signal screen.

MCbrian said:
No, "HTC gps tool" is not the same as QuickGPS and it doesn't do the same thing.
AFAIK, QuickGPS talks to a server and gets info on where/what satellites should be visible for your location, your location determined from triangulation (or some kind of location) of nearby cell towers.
HTCGPStool uses the GPS functionality of your phone in some way that helps subsequent lock on satellites. Honestly, I don't know exactly what/how it does -- but it's not the same as Quick GPS.
Click to expand...
Click to collapse
QuickGPS downloads the ephemeris data so that it can predict where the satelites are, which ones are visible, and which ones to use. From that data it is able to get a fix faster. There is no fix derived from ephemeris data, and any GPS will work without it. The GPS device in that case must basically just scan channels and listen for enough data to get a fix.
That all said; no problems here with Google Maps.. If I'm inside I'll often get a location approximation based on cell ID's and whatever goes on behind that location calculation and depending upon how the building is constructed I may or may not get a GPS signal eventually. For example my house, no problem, I might see the approximate location for 10s then the real GPS location. At work with heavy beamed roofs and several layers of metal between me and the sky I'll never get a signal inside except beside a window. If I'm outside, I nearly immediately get a GPS fix.
http://www.how-gps-works.com/glossary/ephemeris-data.shtml
As far as I know HTC GPS Tool does nothing except allow you to basically reset the GPS, ie: perform a warm or cold restart on it. Perhaps this will help, vs rebooting the phone, if GPS is not behaving. I very rarely will find the GPS is simply not functioning after a reboot.
This tool also might let you change the COM and BAUD but you would not likely need to do that on a phone with a built-in GPS. Even if you were using an external bluetooth GPS I'm not sure you'd want to change the COM/BAUD here, you'd simply use the COM port you set up with that bluetooth device.
That all said, the only time I don't get an immediate GPS fix in Google Maps is if I'm indoors. If I'm in a light structure, like my house, I'll get a cellular approximation for 10-20s. If I'm at work with many beams and much metal above me I'll never get a fix inside.

Let me try to be more specific.
1. When utilizing the app, it locates me within 3100 meters. (pressing the blue button, lower right hand corner)
2. After about 10 minutes of the upper right hand corner stating "seeking GPS satellites (0)" the screen gives me a Weak GPS signal message.
3. I have tried changing com 0-9 ports, with no luck.
4. GPS is enabled
5. I have hard reset the device and reloaded all my working apps.
6. I have uninstalled/reinstalled Google Maps 4.0
7. I have tried different locations throughout Northeast, WISCONSIN.
8. I have tried it while utilizing WIFI. No luck
9. I have tried the Bluetooth remedy. No luck
10. Waiting on replies from HTC, USCC, and GOOGLE.
11. XDA so far is the only place with anybody responding.

HTC Weather TAB
Just got done talking to a USCC tech rep.
He has stated that he is unable to give any technical help with the Google Map app. (no kidding sherlock) He was not even of any help when it comes to the GPS settings, but he did state I am the second person that he has talked to with the same problem.
Now to see how quickly HTC, or Google responds.
The only worry I have is not knowing if it is a hardware issue that should be corrected by HTC. I noticed the HTC WEATHER tab works fine. is this using the same GPS settings as the Google Map app??
also, I have been holding out on the aGPS cab posted earlier. If, and when, I use this fix I will post the results.

dataylor said:
Ok, where is htcGPStool??? Looked through the settings and have not found anything that directs me to HTC gps tool.
Click to expand...
Click to collapse
HTC GPS Tool is not a standard app. Some cooks include it in their custom roms. I don't have a link for it handy, but if you search on the forum boards for "HTC GPS Tool" you'll find it.
That said, I don't know how important it is anyway...

ok, talked to an HTC tech. We checked the settings and these where adjusted. Still nothing. Got rid of Google Maps and tryd BING, and still nothing. HTC TF3D Weather tab seemed to update just fine, this gave the tech a reason to dump me on MSN and Google. Do you really think BING and GOOGLE share some programming similiarities????

Did you run Quick gps? That did it for me when I first got my phone.
It is installed under the programs lists.

dataylor said:
ok, talked to an HTC tech. We checked the settings and these where adjusted. Still nothing. Got rid of Google Maps and tryd BING, and still nothing. HTC TF3D Weather tab seemed to update just fine, this gave the tech a reason to dump me on MSN and Google. Do you really think BING and GOOGLE share some programming similiarities????
Click to expand...
Click to collapse
I think they both access GPS via WM. Maybe HTC Sense (Weather tab) directly access the GPS?

GPS Fix ... soooo slooowww...

Anyone know why my GPS fix is so slow? It takes at least 10 minutes to get a fix..
I'm running - VaniljEclair RLS6
TW,

It really depends on the weather. If you look up and see clouds, it's going to be a while. If it's raining then it may never connect.
It also helps the have the best tools for the job. Use kallt_kaffe's latest kernel, and download and use "GPS Test" for connecting your GPS.

Dukenukemx said:
It really depends on the weather. If you look up and see clouds, it's going to be a while. If it's raining then it may never connect.
It also helps the have the best tools for the job. Use kallt_kaffe's latest kernel, and download and use "GPS Test" for connecting your GPS.
Click to expand...
Click to collapse
It's clear outside so its not weather related.
I'm curious what the"GPS Test" tool actually does? and just exactly what the phone is doing causing it to take so long.
Thanks,

The way GPS works is as follows.
In order to know your position on a 2 dimensional plane, you need 2 coordinates, X and Y, however in order to know your position on a 3 dimensional object, you need 3 coordinates, X, Y and Z, what we need to know is our position in a 4 dimensional space, which requires not only X, Y Z and V, so that's a lot of data right there, and to further complicate things, the satellites themselves are in motion, also in 4 dimensions.
Ok if that hasn't messed with your head, consider this, your phone only receives GPS data from the satellites, it does not transmit anything, so how does your phone know where the satellites are? simple, the satellites transmit their position, the time, their velocity and heading, ( actually it's slightly more complicated, but I'm not getting into orbital mechanics, lol).
So in order to be able to fix a position, your phone must download this data from each satellite in view, process and compare it with all the other data in order to get an initial fix.
As if this was not complicated enough, you must also realise that the satellite data is continually transmitting in an updating loop, so if the receiver gets bad data from one sat, it must discard that set and start again.
Once the initial fix is made, it's a simple matter to continually update the devices position, but once the gps is turned off, it may take some time to resynchronise, especially if the user has moved to another location before restarting gps.
To operate with reasonable accuracy, (within a few tens of metres), you must have a good signal from at least 4 satellites, more just refines the accuracy.
So why ten minutes? Well there are a number of factors, weather does play a part, but not as much as some think, typically you will lose lock on the weaker satellites, giving less accuracy.
Surrounding buildings and trees are actually great at blocking GPS signals, so in wooded or built up areas, expect slower fixes, less accuracy, and dropped locks.
Movement, this is actually the biggest problem, if you are in motion during the initial fix period, there is a high probability that your own motion will cause problems, since the gps data may be changing too fast for the device to cope with, which will cause it to continually discard data that may be valid.
All in all, the best practice is to find somewhere stationary, away from buildings and trees, turn on GPS, and just wait for it to lock, it will usually take 5 minutes from cold start, perhaps up to 10 minutes in some cases.
Once the initial fix is established, it takes less time to refix after gps is turned off, since the last data is kept in the device for future reference, (which is why it can take more time to fix if you turn off gps and then move 10K or so before turning it on again).
Winmo has a few advantages over Android for gps, since on WM you can download a 'snapshot' of the satellite data in order to 'jump start' the gps to get a faster fix, that plus cell location and agps make it much faster to get up and running compared to Android on our hardware, which lacks cell location and agps.
What GPS Test does is simply show you a lot more data than you would normally see, satellite positions, signal strengths, number of sats visible, number in use by you. Basically it lets you see that some data is actually being received by your device, how strong the signal is, and if the device has locked to a satellite. I highly recommend getting GPS Test from market if you use gps, used it on WM, and the Android port is just as good, ( I got the paid version, but the free one is excellent too).
Any questions?

zenity said:
The way GPS works is as follows.
...
Winmo has a few advantages over Android for gps, since on WM you can download a 'snapshot' of the satellite data in order to 'jump start' the gps to get a faster fix, that plus cell location and agps make it much faster to get up and running compared to Android on our hardware, which lacks cell location and agps.
...
Click to expand...
Click to collapse
Terrific write up!
So, GPS Test won't help speed up the positioning so therefore there isn't a need to download it unless your curious about any of the other settings, thanks.
Since the WM version was a bit quicker in getting the position by downloading a file is there something in the works to try and incorporate this process into Droid?
After it finds a fix, if the handset suspends is there a need to re-aquire the sats or wait again for the same process?
Thanks,

Well GPS Test won't speed up the initial or subsequent fixes, but it does give a good indication that gps is actually working, and receiving/processing the data, and once fixed, you just close that and start your preferred gps app, which will fix almost instantly since the data is current.
I don't think we have anything for android that does the same as the WM gps app, could be wrong, but have not seen anything yet.
The slowest is the initial fix, after that it usually fixes faster, suspended or powered down, only reinstall/wipe data will usually require such a long fix time again, however as I said, there are a number of factors, movement being perhaps the biggest cause of delay.
However once fixed, Android is comparable to WM, even better in some cases, since I never could get my all time favourite GPS software (trekbuddy), to work in WM, it is great in Android though

I don't think we have anything for android that does the same as the WM gps app, could be wrong, but have not seen anything yet.
Click to expand...
Click to collapse
i also looked and found nothing
The slowest is the initial fix, after that it usually fixes faster, suspended or powered down, only reinstall/wipe data will usually require such a long fix time again, however as I said, there are a number of factors, movement being perhaps the biggest cause of delay.
Click to expand...
Click to collapse
mine also takes forever every time unless i havnt moved and switch apps within 10 minutes.
However once fixed, Android is comparable to WM, even better in some cases, since I never could get my all time favourite GPS software (trekbuddy), to work in WM, it is great in Android though
Click to expand...
Click to collapse
i lose gps on the highway, unlike when i had wimo
i still think its odd that i can see 6, 7, 8 sats for 2 or 3 minutes before getting a lock

Thinking about trying this on a friends Eris, but other android devices get a lock very quickly. The other devices have working tower location, so does the android gps system use the tower location to speed up gps lock?
I'm going to take my friends Eris and turn off all radio functions, then run GPS test to see what happens and how long a lock takes...

Ok, tried a few things on the Eris. In airplane mode, launched GPS test in a lock in under 10 seconds. Restarted the phone, still in airplane mode, and immediatly launch gps test and a lock in under 10 seconds.
Do these other phones have GPS chips have almanac caching or does the OS have some way of storing almanac data to assit the GPS.

As far as I am aware, from previous experience of GPS devices, the last ephemeris data is cached in the device chipset, allowing a faster start up, provided the user has not moved too far, or left gps off long enough to make the data too old. However I do not have enough information to make more than guess that it is hardware based rather than OS based caching.
Cell tower location allows GPS to establish a 3 dimensional fix, (remember gps needs more than 3 dimensions to establish a true fix), not enough to be totally accurate, but within 20-50 Metres, which is ideal for 'seeding' the incoming gps data from satellite, allowing even faster start up, since the gps chipset does not have to do nearly as much calculation and correlation on the data, since it already knows roughly where it is.
So the delay we experience in getting a gps fix with Android on our devices has one main cause, lack of cell tower location, and it's possible that the ephemeris data cache may not be getting processed, if this is indeed cached by the hardware, and not by the OS.

Some of you may have noticed a file called gps.conf in /system/etc
It looks like this:
Code:
NTP_SERVER=north-america.pool.ntp.org
XTRA_SERVER_1=http://xtra1.gpsonextra.net/xtra.bin
XTRA_SERVER_2=http://xtra2.gpsonextra.net/xtra.bin
XTRA_SERVER_3=http://xtra3.gpsonextra.net/xtra.bin
SUPL_HOST=supl.google.com
SUPL_PORT=7276
NTP is a protocol for getting accurate time from servers on the internet.
xtra.bin is asfaik the satellite almanac.
SUPL_HOST is for AGPS.
My guess is that a "real" android libgps uses this information to do a few things to help the GPS out.
1. Give it the current time
2. Prime it with the almanac
3. Use the AGPS data to provide it with correction data etc.
We could do some HaRET magic to monitor what the QuickGPS software send to the GPS chip and make our own QuickGPS tool for android or even build that into libgps.so. It's possible but is it worth the time? I don't know. I would give it a go if I wasn't allready lacking time to do everything I want to do.

kallt_kaffe said:
Some of you may have noticed a file called gps.conf in /system/etc
It looks like this:
Code:
NTP_SERVER=north-america.pool.ntp.org
XTRA_SERVER_1=http://xtra1.gpsonextra.net/xtra.bin
XTRA_SERVER_2=http://xtra2.gpsonextra.net/xtra.bin
XTRA_SERVER_3=http://xtra3.gpsonextra.net/xtra.bin
SUPL_HOST=supl.google.com
SUPL_PORT=7276
NTP is a protocol for getting accurate time from servers on the internet.
xtra.bin is asfaik the satellite almanac.
SUPL_HOST is for AGPS.
My guess is that a "real" android libgps uses this information to do a few things to help the GPS out.
1. Give it the current time
2. Prime it with the almanac
3. Use the AGPS data to provide it with correction data etc.
We could do some HaRET magic to monitor what the QuickGPS software send to the GPS chip and make our own QuickGPS tool for android or even build that into libgps.so. It's possible but is it worth the time? I don't know. I would give it a go if I wasn't allready lacking time to do everything I want to do.
Click to expand...
Click to collapse
Ah, that makes sense, since Agps uses an internet server to prime the gps chipset, and if I recall correctly QuickGPS is similar, but provides the weeks Ephemeris data. Ephemeris, Almanac and Time are the three main data components of GPS, ( almanac being the one I tend to forget about....).
Perhaps changing a few server addresses in gps.conf may provide us with some aggps functionality, but I am now wondering if perhaps agps is 'broken' in our builds, or perhaps I have never noticed any data activity.
Just had a look at the website address http://xtra1.gpsonextra.net/xtra.bin, which allows me to download what I assume is the data file, so what we need to complete the puzzle is, what uses gps.conf, and where does it put the data file?, Also does anything use that data file if present?

GPS is currently pretty much useless in that it just never gets a fix, today I waited 10 minutes and still nothing - I went back to WM to use GPS, so any development in this area would be sweet!
TW,

Not sure exactly what is going on there, last night I installed the latest nbh from kallt, plus his RLS7b eclair build, this morning I started gps for the first time, using gpstest I got a first fix in under 3 minutes, which is faster than average.
Sent from my HTC Kaiser using Tapatalk

zenity said:
Not sure exactly what is going on there, last night I installed the latest nbh from kallt, plus his RLS7b eclair build, this morning I started gps for the first time, using gpstest I got a first fix in under 3 minutes, which is faster than average.
Click to expand...
Click to collapse
I'm using the same setup at the minute, tried GPS this morning and it got a fix on the move in about 5mins which isn't bad, my girlfriends HTC Hero got a fix in under a minute though and it's the first time it has connected and it's true that WM is much faster when quickGPS is updated. Any improvements here are very welcome, maybe i'll have a look into it too.

you could edit gps.conf according to your own pool server
a list of these servers can be found here. May make a small difference for some people.
Please post if this helped getting a quicker fix
http://www.pool.ntp.org/en/
Update:
i used the appropriate time server for my country (netherlands),
i used a fresh device (android had never ran on it, though the android on sdcard has been used on other devices)
i went to the toilet very quick, when i came back there was a fix.
So please go see if this makes a difference for you, and post your experiences in here

I seriously don't think it will matter what you put in gps.conf at the moment. What we need to know is how this is used on a "real" android phone.
I've tried to find some GPS code in the Hero kernel source in the past but found almost nothing and the libgps for HTC devices are asfaik closed source so I guess it's in libgps all the "magic" takes place. (I fact, for Kaisers the it would be more "right" to do our NMEA parsing in libgps instead of doing it in the kernel but since libgps evolved around the Vogue it was made in the kernel to make it appear just like the vogue gps data to libgps.so.)
So I'm guessing that a "real" libgps.so reads gps.conf, get's some data and feeds it to the GPS. Likely with AT-commands. It is possible though that it is the ril interface that does it. We have the source for our ril lib and our gpslib and I know for sure we don't do any prime:ing in the our libgps. (The sources are here: http://androidhtc.git.sourceforge.net/git/gitweb-index.cgi?p=gitroot/androidhtc/bootenv/)
It is possible to do dump stuff with HaRET when you for example enable the GPS (I've done it in the past following instructions from dzo) and also when you run QuickGPS and try to match the information sent with the information in xtra.bin. I also expect we should find it sending the current UTC time which by it self propably could speed up fix times.
Once we know what to do we either build it into libgps or we make an Android app similar to QuickGPS.
In fact, I found some dumps laying around....
At boot WinMo sends the system time to the Radio with this command:
[email protected]=2,21,43,2010,5,12
I would say the format is H,M,S,YYYY,M,D even though values are a bit strange because the files are dated 2010-05-11 but it's possible that the WinMo clock was a bit f*cked up at the moment.
Perhaps our rild is allready sending this (someone should check the source)
Otherwise you could try this and se if it helps:
echo -e "[email protected]=x\r" > /dev/smd0
(replaceing the x with the current time and date of course)

Just tried and it was going on 10 minutes with no fix...
TW,

Have you tried gpstest to see if it's actually receiving a signal at all? It is possible that you have a hardware issue, perhaps a broken antenna connection?

If that were the case then it shouldn't work in Windows and it does... ???
Strange...
Does Android require a data connection when getting a GPS fix?
TW,

GPS receiver chip is not the cause of the problem

Guys,
According to this site, the problem with the GPS is the software Google Maps
Read this:
http://samsungi9000galaxys.com/galaxy-s-gps-review-sygic-gps-signal-and-gps-lock-times/
So it seems that using other Navigation software gives very good GPS performance.....
But how come using the GPS TEST software also shows that the GPS is loosing sattelites lock and erratic performance? I mean if the cause of the problem is the Google Map, testing the GPS receiver using GPS TEST should show good signal lock and stable reception isnt it?

widjaja74_us said:
Guys,
According to this site, the problem with the GPS is the software Google Maps
Read this:
http://samsungi9000galaxys.com/galaxy-s-gps-review-sygic-gps-signal-and-gps-lock-times/
So it seems that using other Navigation software gives very good GPS performance.....
But how come using the GPS TEST software also shows that the GPS is loosing sattelites lock and erratic performance? I mean if the cause of the problem is the Google Map, testing the GPS receiver using GPS TEST should show good signal lock and stable reception isnt it?
Click to expand...
Click to collapse
It's a software setting: http://forum.xda-developers.com/showthread.php?p=7281059
Other android devices have the same problem with a wrong setting.

Its not true, I tried google maps, co-pilot and NDrive and all gave really, really crappy gps performance. Upgrading to JG5 firmware has improved things a lot but its still pretty unusable for me.

You know I was just about to post that I think the issue is with google maps and not the phone. If I apply the ntp europe fix my gps locks very quickly and stays locked to within 16 feet in gps test when driving about.within google maps navigation the performance remains as shocking. Arrrggghhh!
Sent from my GT-I9000 using XDA App

I wish i could help testing the phone with different GPS/navigation software to validate the analysis, but I already sold my phone last week out of desperation due to the the GPS problem and lag problem and phone freeze problem and signal drop problem when you hold it a certain way....
but i love the design, size of the screen, the thinness of the phone and the super amoled display.....

Ouch...
Why did you not return your phone instead? I have never had my SGS freeze and I have never been able to drop a call by cupping the antenna, altough the signal strength does go down, wich it will on ALL phones with built in antennas since you are shilding the antenna... ( NOT SAME AS IPHONE4 design flaw where you shortcircuit 2 different antennas and that part seems particulary hard to grasp for some on this forum....)
But, to get on subject again, the GPS has been bad, that is for sure and I hope this is a step in the right direction.

Its clear that testing the gps is waaay too subjective and subject to too many factors. Applications have no effect on the gps performance.
Sent from my GT-I9000 using XDA App

My gps has been working perfectly with 3 firmwares.. it's much faster then the one on my old iphone 3G
Sent from my GT-I9000 using XDA App

My GPS seems to be very hit and miss, but it has worked on the several occasions that I have really needed it (getting lost).
And widjaja why are you still shambling about this forum when you sold your phone? get back under your bridge.

Once again, another thread started because someone made one change, tested it and it worked, then posted how great it was. Trouble is since the GPS can work fine for days on end, and then not work for days on end, these supposed cures are pretty much all wrong.
The GPS doesnt work, and so far there hasnt been a public explaination as to why, just lots of guesswork, and no fix has been released (in any of the firmwares available today). It's coming, but its not here yet.

TravUK said:
Once again, another thread started because someone made one change, tested it and it worked, then posted how great it was. Trouble is since the GPS can work fine for days on end, and then not work for days on end, these supposed cures are pretty much all wrong.
The GPS doesnt work, and so far there hasnt been a public explaination as to why, just lots of guesswork, and no fix has been released (in any of the firmwares available today). It's coming, but its not here yet.
Click to expand...
Click to collapse
Seems some phones work some dont.On jf3 my gps was shocking but on jg5 it has always been spot on with google navigation and co pilot and ive tested it a lot in all weathers.It has never lost lock and is always bang on with position.I even tested google maps satalite view in the car parked next to a tree and it had me right next to the tree-within 10 feet accuracy.I dont change any settings just leave it on whatever settings jg5 uses.Im in england if that makes any difference

Found a fix on another forum and its been working pretty well for me.
Enter *#*#1472365#*#* in the dialer to enter GPS settings and change the following:
Application Settings:
Operation Mode - MS Based
Use SkyHook - ON
Accuracy - 30
SUPL/CP Settings :
Server - supl.google.com
Server Port - 7276
SUPL Secure Socket - OFF
I was having problems with 3G and WIFI with these settings at first, so I left Operation Mode on Standalone and Skyhook OFF. Works great now. Just tested it and got 9 satellite locks and 5 in use.
source: http://www.mobile01.com/topicdetail.php?f=568&t=1661500&r=2&last=21080924
I'm in Hong Kong btw running local JF7 firmware. Hope this helps.

I'm almost convinced that most of the problems people are having is down to google maps. I'm not saying that tweaking the settings as people have, inc me, doesn't improve maters, but I believe there is an underlying compatibility issue between google maps and the galaxy which is making the issue seem worse than it is.
If I leave gps test running while driving I get at worst a lock down to 32 feet, speed is accurate and never lose lock even when on roads totally covered with big wet trees. It looks spot on.
Google maps navigation can't even get me in an accurate position when stationary, start driving and its bloody awful jumps all over the place and sometimes doesn't even move for 30 seconds after I've pulled away from a junction.
I've updated my supl settings to use google (manually edited the conf file, I don't use the hidden menu screen because even if you change nothing it makes changes to the conf file on exit, delete the file and reboot to refresh it) and updated my ntp settings to use europe.
In the jg5 rom google maps is built in, so I can't reinstall it or seem to be able to clear the cache to see if that helps in anyway.
It wouldn't surprise me if any gps fixed rom released by samsung contains a tweaked version of google maps that works.
Sent from my GT-I9000 using XDA App

Location wrong without WiFi/GPS/Edge

Hey guys,
I tried searching on google but to no solution.
The problem is when I switch off all forms of data except cellular coverage, my location changes to a City where I'm not at. I went to that place maybe thrice since I got the phone.
My location in Maps, Weather or even location saved along when I take pictures will be that other/wrong location.
Its easily fixable by just starting one of the data services, but why should I even face it in the first place.
Its happened on all ROMs and wipes don't fix it. Done a full wipe twice from cwm.
My GPS works normally when I'm using maps, it takes about 30 seconds to get a lock on my location.
Any workaround or solution or fix? (except for not keeping data switched on all the time)
Thank You.
Cheers.

death__machine said:
Hey guys,
I tried searching on google but to no solution.
The problem is when I switch off all forms of data except cellular coverage, my location changes to a City where I'm not at. I went to that place maybe thrice since I got the phone.
My location in Maps, Weather or even location saved along when I take pictures will be that other/wrong location.
Its easily fixable by just starting one of the data services, but why should I even face it in the first place.
Its happened on all ROMs and wipes don't fix it. Done a full wipe twice from cwm.
My GPS works normally when I'm using maps, it takes about 30 seconds to get a lock on my location.
Any workaround or solution or fix? (except for not keeping data switched on all the time)
Thank You.
Cheers.
Click to expand...
Click to collapse
Location without GPS is online service. I hope that answers your question about "fixing" it.
Sent from my HTC One X using xda premium

There's three things at play in plotting location: 1) GPS, 2), aGPS, and 3) Geo-location
GPS is the onboard chip functioning alone to pick up satellite signals and lock on them. You can test how well your GPS chip alone works by putting the phone in airplane mode and rebooting it.
All aGPS does is use a wireless signal (Wi-FI or cellular) to help the chip get its first lock faster. Once lock is established the chip is on its own.
From Wiki...
"Assisted GPS is a system which can, under certain conditions, improve the startup performance, or time-to-first-fix (TTFF) of a GPS satellite-based positioning system. It is used extensively with GPS-capable cellular phones as its development was accelerated by the U.S. FCC's 911 mandate making the location of a cell phone available to emergency call dispatchers."
Geo-location uses wireless signals alone to approximate position. Devices w/o a GPS rely on this for location based services.
From Wiki...
"Geolocation is the identification of the real-world geographic location of an object, such as a radar, mobile phone or an Internet-connected computer terminal. Geolocation may refer to the practice of assessing the location, or to the actual assessed location."
Once the chip locks, it memorizes the position of the satellites. So if you had your wireless on to get first lock and then turned it off the chip is still using the satellite locations aGPS helped it find. If you want to test the performance of your chip itself reboot it in airplane mode. Download GPS Test from Play. It'll give you a much better picture of what's happening with your phone. I just tried it on mine and indoors it locked and got down to 15’ accuracy in less than a minute. Conditions affect performance but, at least outdoors, yours should do as well or better than mine. If it doesn’t, it’s a h/w problem.

tkolev said:
Location without GPS is online service. I hope that answers your question about "fixing" it.
Sent from my HTC One X using xda premium
Click to expand...
Click to collapse
BarryH_GEG said:
There's three things at play in plotting location: 1) GPS, 2), aGPS, and 3) Geo-location
GPS is the onboard chip functioning alone to pick up satellite signals and lock on them. You can test how well your GPS chip alone works by putting the phone in airplane mode and rebooting it.
All aGPS does is use a wireless signal (Wi-FI or cellular) to help the chip get its first lock faster. Once lock is established the chip is on its own.
From Wiki...
"Assisted GPS is a system which can, under certain conditions, improve the startup performance, or time-to-first-fix (TTFF) of a GPS satellite-based positioning system. It is used extensively with GPS-capable cellular phones as its development was accelerated by the U.S. FCC's 911 mandate making the location of a cell phone available to emergency call dispatchers."
Geo-location uses wireless signals alone to approximate position. Devices w/o a GPS rely on this for location based services.
From Wiki...
"Geolocation is the identification of the real-world geographic location of an object, such as a radar, mobile phone or an Internet-connected computer terminal. Geolocation may refer to the practice of assessing the location, or to the actual assessed location."
Once the chip locks, it memorizes the position of the satellites. So if you had your wireless on to get first lock and then turned it off the chip is still using the satellite locations aGPS helped it find. If you want to test the performance of your chip itself reboot it in airplane mode. Download GPS Test from Play. It'll give you a much better picture of what's happening with your phone. I just tried it on mine and indoors it locked and got down to 15’ accuracy in less than a minute. Conditions affect performance but, at least outdoors, yours should do as well or better than mine. If it doesn’t, it’s a h/w problem.
Click to expand...
Click to collapse
Thanks, that was a very informative post.
Well I switched on GPS and put my phone in airplane mode and restarted. The Maps App keeps saying "Your current location is temporarily unavailable" and I can't figure how to use the GPS Test yet.

Okay, I did get a lock-on from the Maps and the GPS Test app. I went closer to my window lol . Now I'll see if my location comes up wrong.
Edit:Location came up accurate in weather.
Edit2:Location is accurate in a photo I clicked with everything off.
By accurate I hope you understand what I mean, when all the data goes off the phone should still think its in the place/location where it was when the data was on. Ii.e Surat in my case. But what used to happened before today(gps in airplane) was without data the phone will think its in Pune, which is a 12 hours drive from here.
I'm not the only one who's faced this, some say its a bug in sense :/
Anyways here's a thread I saw earlier
http://www.htconesource.com/forum/htc-one-x-discussion/1042-incorrect-location.html
The answers the guy gets are retarded.

To be sure, are you saying that when only on mobile data and relying upon that, you cannot get an accurate location down to 1 KM?
If so, this sounds like a software issue or a carrier issue.
If your GPS has poor reception then I would advise getting warranty repair. It might have the same issue as the Wifi antennas do.

Yeah just so you know pure GPS is line of sight, you have to have a clear view of the sky to work (no clouds either).
Sent from my HTC One X using xda app-developers app

Hunt3r.j2 said:
To be sure, are you saying that when only on mobile data and relying upon that, you cannot get an accurate location down to 1 KM?
If so, this sounds like a software issue or a carrier issue.
If your GPS has poor reception then I would advise getting warranty repair. It might have the same issue as the Wifi antennas do.
Click to expand...
Click to collapse
jonshipman said:
Yeah just so you know pure GPS is line of sight, you have to have a clear view of the sky to work (no clouds either).
Sent from my HTC One X using xda app-developers app
Click to expand...
Click to collapse
No no.
My location when all services are on shows up fine. But say I have a weather widget and all my data services are off, instead of showing the location detected last when data services was on the widget and other settings will show another city.
I'll explain it with an example.
Lets have a hypothetical country with all the letters as its cities.
I stay in 'S' at present. I have visited 'P' and 'M' a couple of times but I'm back to 'S' now. On the occasion that my data services switch off, intentionally or because of weak coverage. Instead of showing 'S' as my location in the weather widget, app and geotag the phone will show 'P' which I had visited days ago.