yashsingh1/xdaforums huggingface dataset:
[Acer Iconia A500] drharisis:
Just tested the new release...It is as good as test build 5 ,,but not quick lock(cold start)After locating the sats if I am going to use again gps I take then a quick lock...Thanks for trying to help us:)
[Acer Iconia A500] crypted:
If someone will send me a private message containing the files from /etc/gps/ and /data/gps/, and the /etc/gps.conf if it exists FROM the stock ROM, I would be appreciative.
[Acer Iconia A500] drharisis:
I have fleaxreper 11 rom..Does it include the same files???
[Acer Iconia A500] crypted:
Honestly, I don't know. You could send me whatever it has before you flash this ROM.
[Acer Iconia A500] drharisis:
I have not the stock rom..I have flashed the fleaxreaper rom without keaping an update...
[Acer Iconia A500] pacificwing:
So i was looking through the GPS log debugging info and I found the following lines appear in every instance where I try to use my GPS.

$297083I Start reading LTO ...
LTO file was not found!
$297083I LTO reading complete.
$297083I LTO ignored (integrity)
$297083I Start reading CBEE file ...
EE file was not found!
$297084I CBEE file reading complete.
$297084W Warning: Using default vertical accuracy (45.000000)
$297084I Serialize REFPOS: (49.234780, -123.025234, 0.000000)(0) OK

I'm assuming LTO is the lto.dat. Not sure if this is causing the issue.

I was running GPS outdoors, with the latest patch from this thread (google NON-SSL). I was seeing 3-4 satellites, but they were not locking. I did have wifi access enabled and it was working.

Dunno if these means anything. Unfortunately, there is very little information out there on gps log outputs.
[Acer Iconia A500] crypted:
There should be an LTO file in the /data/gps/ folder. Its download is controlled by the GPSD and not in my script. See if it exists and report back. If the directory doesn't exist, create it.

Try flashing the Transformer Prime v1.0 and let me know how that goes out of sheer curiosity.
[Acer Iconia A500] pacificwing:
Transformer Prime caused by GPS to stop working entirely. I reverted back.

The only file in /data/gps is a file called gldata.sto

The GPS seems to dump the log files in here as well. There are a lot of those. They are named gl-<data><randomnumber>.txt. That is the file that generated the code above.
[Acer Iconia A500] crypted:
Okay so we have some stark deviations in configurations of ROM's here. Some use XTRA, some use STO, and some use LTO. Holy crap Batman. Not fun for me here at all.

I need original gps.conf and all files from /etc/gps/ and /data/gps from the ROM you're using before my patch. And, I need that from a lot of ROM's by the look of it that way I can try and figure out why the hell this device has such randomization in it.

It used to work for most people before these new ROM's started dumping out! Ugh!
[Acer Iconia A500] pacificwing:
HaHa! They can't make it too easy for you!

As I understand it, Flexreaper (the rom I'm using now) is based on the latest honeycomb leak. With the exception of Thor's, which rewrites everything from the ground up, I expect most of the major ROM releases here to have the same basic data.

Might I sugest downloading the stock ICS 4.0.3 leak from here and using the files from that?

http://xdaforums.com/showthread.php?t=1524736

My current ROM has been so bastardized from tweaking and fiddling I doubt it would be much use to you.

Cheers,

-PW
[Acer Iconia A500] Zoandroid:
Working on ICS Lightspeed ROM

I just wanted to say thanks for this nifty GPS patch, and that I have now used it on 3 devices with success. A Droid X running CM7, My A500 tablet when it ran Thor's HC 3.2.1 version 14, and now as of tonight the same A500 tablet running Lightspeed ICS ROM version 4.4.

To make it work with the ICS ROM, I had to add your suggested line "ro.ril.def.agps.mode = 1" to the build.prop file. Just changing the gps.conf (which is what worked the first 2 times) wasn't enough. With that line also added, I have fast GPS lock using GPS Status as well as using Latitude on the A500.
[Acer Iconia A500] pacificwing:
I went back to Thor's 14.2 tonight, to try and figure out why it works so much better on that ROM.

After looking over the filesystem, and the logs, I found one noticeable difference:

/data/gps/lto.dat

It exists in the old Thor 14.2 rom, but it is not generated or successfully pulled in any other ROM.

Anyway, apparently this file (long term orbit data) holds some critical information for the locking component of satellites. Without it, you may see multiple satellites, but locking on could take ages. This file speeds up locking considerably.

For more information, here is a link:

http://www.broadcom.com/collateral/tb/LTO-TB100-R.pdf

Anyhow. You can get the file here:

http://gllto.glpals.com/7day/latest/lto.dat

Unfortunatly, I won't be able to test it until morning. But everything I've read (including my log file above) indicates that that file is supposed to be there, and is not getting pulled. I've downloaded the file onto a clean install of Flexreapers ROM, and am going to place it in /data/gps/.

I'll let you know how it goes tomorrow morning. It may be that including this file into your patch could result in better performance on the A500. That may not be viable though, since apparently the file is supposed to be updated every 7 days for optimum performance.

It still doesn't explain why the file is not getting generated/downloaded in the first place though. But that is another issue.

EDIT:

Okay. So I've not been upstairs to try it yet, but I can say from the logs I'm getting much fewer error messages with this file present. It's looking hopefull.

On that note: Any idea where I might get a copy of the "/data/gps/cbee.cbee" file I'm apparently missing?
[Acer Iconia A500] maris__:
Incredible, you found it!! I tested lto.dat with FlexReaper R.11, and get almost an immediate SAT fix indoors that doesn't get lost (when the tab is placed near the window). Thanks!!

Best regards, maris
[Acer Iconia A500] pacificwing:
That's really good news! I'm glad. I can't wait to test it tomorrow.

Now that we know *what* the problem is, it looks like the next task is to figure out *why* this file isn't getting downloaded. Maybe there is a setting in gps.conf or gpsconfig.xml which is responsible for instructing the unit to download this file.

We are still missing the extended ephemeris (CBEE) file, which could speed things up even faster. No idea where to get that.

I'll keep looking into it.

EDIT:

I just went outside and tested it, and yes, it appears to have been the problem. crypted, you may want to add this revelation to your long list of notes.

The next step is obviously to figure out why the file isn't being downloaded automatically, since it will have to be updated manually every 7 or so days.

Cheers, and goodnight.

-PW
[Acer Iconia A500] crypted:
The GPSD controls downloading of that file. There aren't parameters to set in the conf. The only thing I could think of for my Prime was to write a bash script to download it. I didn't try to figure out what Android supports via /usr/bin/ executables because mine downloads like it should.

Y'all need to railroad your ROM Dev's to resolve the lack of LTO support in their structure. Then, I'd consider the Prime patch since LTO appears to be the file needed for this device instead of the others.
[Acer Iconia A500] Zoandroid:
Thanks for the heads up on this extra file! I downloaded it and put it in gps/data and rebooted. GPS Status now locks onto several satellites within seconds, from an interior room in my house.

Do you mind if I repeat this added data in the GPS thread over on Android Forums?
[Acer Iconia A500] crypted:
I'll make a new zip with it included for everyone.

I'll assume it's like many Linux operations and must be existent to update.

Or if this won't be useful tell me so I don't waste my time. I can do it within the next 6 hours.
[Acer Iconia A500] Zoandroid:
For my 2 cents, simply having the files and being told where to put them using an app like Root Explorer is the way I chose to go. I did not try using any method to flash them into position. It seemed overly complex.

Thanks again for your efforts on this! Without it, the GPS function on my devices was laughable. Once again the dev community shows how it can make things work so much better than the product vendor software team. :-) Perhaps they spend all their time looking for bloatware to add instead of honing the device performance as they should.
[Acer Iconia A500] pacificwing:
That's the thing. I don't know if this file requires constant update, or if it is a one time shot. I'm told it will expire after 7 days. I guess we'll find out. The other thing is that when you force clear your AGPS data (through GPS test), the files goes away. So just because it is in the patch, doesn't mean it's going to stay put.

Adding it as part of the patch might be premature. I would just add a note to your parent thread letting people know to try it if they aren't getting results.

I think until we figure out how to force the system to add the file on its own, this is just a band-aid that some people need to be aware of. There are people who claim not to need it, which makes me think that this is a problem limited to a select group of people.

By all means. Spread the word. The more people who know about it, the more likely Acer is to do something to fix it. I would like the fix to be official, but I'm guessing like most things, the dev community is going to have to do it for them.
[Acer Iconia A500] crypted:
Have you set its file permissions to read only for all but root? See if this keeps it from being removed? Not sure if that'll help as we don't know what's deleting it.
[Acer Iconia A500] jlary:
Just to add another voice to this, I'm using KJY2010's Honeylicious Flash Glass (HC3.2.1) rom. It only has the gldata.sto in /data/gps. I downloaded the lto.dat and put it in /data/gps (also changed permissions to 644) and now I get an almost immediate lock indoors using 8/9 satellites that is dead on when looking at the location via the Map app.

Jeff.
[Acer Iconia A500] crypted:
So the patch plus the LTO.DAT is the necessary predicate for success at this point? I really am perplexed that it is not being loaded automatically at all and that it removes the file without fully refreshing it.

Not every person is having this issue with GPS not functioning without the LTO file. It appears to be a ROM specific issue. My curiosity would be the same base for the ROM's needing the LTO or what differences there may be.

Also, did the stock ROM use LTO at all? Or, what files did it have?
[Acer Iconia A500] maris__:
My impression is that without LTO.DAT aGPS is not working, and your modified gps.conf files are almost without function. LTO.DAT is seems to be missing in all Acer ROMs. There was a single custom ROM for the A500 that has been devloped from an Asus android HC version. This custom ROM included the LTO.DAT and showed much faster sat fix than all Acer based ROMs. So it is likely that there is a general failure in all Acer ROMs to download this file.

Best regards, maris
[Acer Iconia A500] crypted:
I would be hardpressed to agree that the modified patch is worthless here. A lot of other users noted that it was successful in the past.

I can see the issue you state with the LTO.DAT hindering some people. But, from personal and others' tests I can say it appears that it is not necessary for LTO-using devices to operate properly in a majority of cases. The issue comes down to what I ponder as hardware and software mixed in causing the issue for those who cannot get GPS going without LTO.

In the above paragraph is based upon LTO.DAT, my personal observations on the Transformer Prime and comparing to others' observations on that device. It may not be this particular device but the process remains similar.
[Acer Iconia A500] maris__:
No, I did not want to say that the patches are worthless in those ROMs. But adding LTO.DAT seems to have even a larger effect on sat fix than the patches.

Best regards, maris
[Acer Iconia A500] pacificwing:
I agree, the patch is far from worthless. It does improve gps efficiency, and I'm using it now. It will continue to be usefull after this LTO problem is resolved.

I wonder if more people need this LTO patch then we realize. As I've mentioned on other threads, active WPS (wifi location) can fool someone into thinking their gps works fine, if they are only using google maps (or some other mapping program) as reference.

I would wager that anyone using a ROM based on stock is having this issue, whether or not they realize it.

Until we have a perminant fix, we should do what we can to educate people to the benifits of both the LTO fix, and the benifits of the patch. They also need to be shown to use "gps test" for reference, rather than just maps.

Cheers,

-PW
[Acer Iconia A500] Zoandroid:
I disagree. The modified gps.conf all by itself turned the GPS on 2 phones and my tablet from useless into instantly locking on and being accurate. Often it will actually show WHERE in my house I am sitting when viewed from Google Maps!
[Acer Iconia A500] shaun298:
Where else can I get the lto.dat. the link above just loads my screen with junk and no download. Or am I doing it wrong. Thanks
[Acer Iconia A500] crypted:
Save the file instead using the "save link as" options in your browser.

When you say junk, I assume that it is probably the code inside the file being shown to you rather than downloading.
[Acer Iconia A500] shaun298:
Yes it is the code being displayed. Thanks for help, going to try it out.

Got 11 locks in 5 seconds. Yea
[Acer Iconia A500] crypted:
I don't have a stable method to keep the lto.dat downloaded or unremoved at this point. I would like someone to review setting the file permissions to read-only to see if this protects it.
[Acer Iconia A500] maris__:
Unfortunately not. Tried that last night.

Best regards, maris
[Acer Iconia A500] crypted:
I was doubtful but held out some hope for y'alls device to not be such a pain!
[Acer Iconia A500] Zoandroid:
When exactly is the lto.dat file getting removed for you guys? Mine was indeed missing just now after having put it there last night. So I put another copy of it in the system/etc file, (for my own convenience if I need to keep replacing it) and then used Root Explorer to remove all the Write permissions. I then copied that altered file and placed it in system/etc/gps. I ran GPS Status which took 20 seconds to lock (lying flat). Then I rebooted, and the lto.dat files are still where I put them. Ran GPS Status again (standing vertical) and it locked in 5 seconds. Checked once again and the lto.dat files are still there. I'll monitor the situation and report back if they disappear.

Also, I don't know if you folks are aware of something else I learned from another source. Standing up the A500 makes the GPS lock in much faster. For some reason the GPS doesn't like working as well when the tablet is horizontal.

I have a lot of problems with my tablet's GPS compass requiring recalibration pretty much every time I use GPS Status. It may be a result of the computers and peripherals nearby where I leave it to charge overnight. But my phones have historically had the same problem, and they charged in a different room. Or, it could just be me. Early versions of digital watch displays used to go blank on me when I wore one (even the first day). If I left the watch sit it would come back. For over 20 years I have worn analog watches because of this.
[Acer Iconia A500] maris__:
There is an option in GPS Status fir resetting AGPS assistance data (don't no the exact term). I used this funciton, and tested whether lto.dat is still present, which is not the case, even not, if the permission settings are changed to read only.

Best regards, maris
[Acer Iconia A500] Zoandroid:
OK, I just tried the same experiment with the Manage A-GPS tool in GPS Status. I tried downloading, I tried resetting, I rebooted. I even force-closed, cleared cache, and cleared data on the GPS Status app. But it seems nothing is affecting the lto.dat file for me. It stays right there in system/etc/gps. After doing all that I was getting a location in GPS Status quickly, (yellow bars) but not a lock (green bars). I had to calibrate pitch and roll and calibrate the compass before it would lock again. Probably because I had cleared its data file?

When you changed the permissions on lto.dat where was the file residing, and exactly how did you change them? What I did was copy the downloaded file into the system/etc. folder. I then used Root Explorer's context menu listing for Permissions, and unchecked all the Write permissions. I saved the file, then copied it and navigated in Root Explorer to system/etc/gps, then pasted the edited file there. Since doing so it has not disappeared no matter what I do.

Root Explorer shows the permissions for lto.dat as r--r--r--.
[Acer Iconia A500] crypted:
That was what I figured would happen as far as doing the CHMOD/persmissions on it via an explorer app. Will be interested if others can repeat the process.
[Acer Iconia A500] maris__:
You've been putting the file in the wrong folder! We are talking here about copying lto.dat to /data/gps. In /system/etc/gps, it doesn't have any effect.

Best regards, maris
[Acer Iconia A500] crypted:
good catch. didn't see that at all...
[Acer Iconia A500] pacificwing:
Hey guys. Just so you know, I'm an idiot. I should have checked for this sooner.

Use this link instead:

http://gllto.glpals.com/30day/v2/latest/lto2.dat

Rename the file from "lto2.dat" to "lto.dat" and stick it in the same location.

This will give you 30 days of orbit data, rather than 7. You'll notice the file is quite a bit larger. I need someone to test it for me though, and make sure it works as well as the other one. The Broadcom data sheet says this format should be fine, but I can't actually test it right now where I am.

Still working on a permanent solution. I am making progress. I'll keep you updated.
[Acer Iconia A500] Zoandroid:
Oops! Sorry about that. Originally the gps.conf file had been stated to go in system/etc/gps, and when the lto.dat file came up I did see that it was supposed to go in data/gps. But somewhere along the way I got back to focusing on system/etc/gps and started putting it there. They say the mind is the first thing to go. I can't remember the second thing. :D

I will re-test!

:)
[Acer Iconia A500] elborak:
Works just as well as the 7 day for me.
[Acer Iconia A500] Zoandroid:
OK,

I retested putting the lto.dat in the data/gps folder. It does help more being there. :D

Anyway, what I found is that I can use the Manage A-GPS State tool to "download" and it has no effect as far as losing the lto.dat file. Only if I use the Manage A-GPS "reset" tool does the lto.dat file get deleted.

Seems like the simple thing to do is never to use "reset" without manually placing a copy of the lto.dat file back where it belongs.

Has anyone been in touch with the GPS-Status app developer (support@eclipsim.com) about this? Perhaps he could update the app to make sure this file does not get removed when the "reset" tool is used?

For whatever it is worth, I just emailed the developer and asked him to check out this thread starting on page 30.

---------- Post added at 10:54 PM ---------- Previous post was at 10:24 PM ----------

How about a little action out of left field?

I decided to check out the files having been discussed above on my Droid X, which is rooted running Cyanogen Mod 7 on Gingerbread .650 kernel.

Having applied the originally suggested gps.conf file to it, GPS-Status, as well as other GPS related things like Latitude and Navigation, lock in very quickly. But.....

There is NO incidence of a "gps" folder ANYWHERE in its file structure.

No data/gps

No System/etc/gps

And of course no incidence of an lto.dat file anywhere either.

???
[Acer Iconia A500] pacificwing:
As far as I know, Broadcom owns the patent on LTO, and as i understand it, usually only Broadcom chips use that data. It is basically their propriatary version of an ephemeris table (almanac data). As such, the Broadcom drivers work much better with that form of data.

LTO is actually meant to be used as a offline substitute to traditional AGPS. This shows a drastic improvement on A500 tablets, because I remain convinced that Acer never actually enabled the "a" in "agps" on their stock kernel. As such, it is really the only form of network assisted satellite location for the A500 that we have currently. Your phone has the benefit of working aGPS, so it doesn't need the local LTO file.

http://www.broadcom.com/products/GPS/Location-Based-Services/LTO-AGPS

Dunno what kind of chip your droid has, but different chipsets will have different drivers, which will run different services.

If you look at your vender spicific boot sequence on your A500 (/init.picasso.rc), you will see a little ways down the file were the gps daemon is called (glgps_nvidiaTegra2android). You will also find it reference gpsconfig.xml as the primary configuration file. I'm betting your phone doesn't have that file. That tells you a lot right there (different chipset, different files, different almanac databases).

I also have a Samsung galaxy nexus (great phone btw) and the gps is a whole different ball of wax. Further to that, cellular phones usually get faster cold locks than tablets, because they have the benefit of cellular triangulation. Wifi only tablets don't know where they are when they start up, so they assume they are at their last known location. This can actually work against a gps trying to establish an initial lock without updated ephemeris data.

Keep in mind, in the addition to different chipsets, the different versions (gingerbread to ICS) have moved things around too.

Cheers,

-PW
[Acer Iconia A500] Zoandroid:
Thanks. This is all very educational, and interesting to learn. :) You are correct. My DX has no gpsconfig.xml file either. As far as what GPS chipset it uses, that I do not know.

I am familiar with the issue of starting a GPS unit in a location many miles distant from its previous location when turned off. We dealt with that using them on boats. I just wish that unit on the last boat I had could have locked in as fast as I am seeing on this tablet! It used to take several minutes, not unlike how these phones and tablets are without the assistance provided in this thread.
[Acer Iconia A500] crypted:
This is why I was suggesting people try my Transformer Prime patch rather than this Qualcomm one. However, you'd be surprised to know that a number of devices, including the Prime, have support for xtra.bin. I stopped using it in the Prime's configuration file because it was redundant and unnecessary because the primary file is the LTO and it works wonderfully.

I would ponder the Prime patch with someone manually copying the LTO file over. I know the patch was tried and was unsuccessful; however, I do not recall the LTO being put on the device with it from discussions above.

EDIT: Android still has need for the gps.conf but is moving towards the XML system and the LTO data structure throughout the manufacturers. A number of manufacturers have dropped the .conf entirely. However, the did so without considering it being necessary. In essence, they failed to do a typical Linux MUST. You keep the legacy files around for a bit until EVERYTHING is changed, not just key parts here and there.
[Acer Iconia A500] Zoandroid:
I have implemented this file, and it seems to work well for my tablet. Thanks. Maybe someone could write an app that updates this file monthly?
[Acer Iconia A500] crypted:
The problem now is that the device deletes the file instead of updating it when an update runs. Can't really overcome that without knowing what is causing the rm -rf.
[Acer Iconia A500] Zoandroid:
"when an update runs" - you mean updating your GPS Fix patch?
[Acer Iconia A500] crypted:
A lot of times this is gpsd controlled and apps like status just invoke that call.