yashsingh1/xdaforums huggingface dataset:
[Acer Iconia A500] pacificwing:
Actually, you can. I've found a way that prevents most programs from deleting the file.

I moved the file to the following address:

/sdcard/Download/lto2.dat

That directory is immediately where my browser wants to put it by default when I download it. This makes it easy. Then I changed gpsconfig.xml to add/change the following lines:

ltoFileName="lto2.dat"

acLtoDir="/sdcard/Download/"

You might have to add that second line. I changed the filename to lto2.dat to prevent having to rename the 30 day files. This is mostly for convenience.

This seems to have the added bonus of preventing the file from deleting during a AGPS update call. Although I've not tested it with every possible outcome yet.

Carefull suggesting this patch to A500 users. It may totally kill thier GPS. Here is why:

gpioNStdbyPath="/sys/class/gpio/gpio162/value"

needs to be:

gpioNStdbyPath="/sys/class/gpio/gpio203/value"

After that it appears to work. Just for reference.

Cheers,

-PW
[Acer Iconia A500] crypted:
Seems I can make a quick build for this device referencing that info. Shall build it and let y'all try it. Gimme a little bit.
[Acer Iconia A500] crypted:
New Build - ACER ICONIA TEST 1

All, I have prepared a custom test based on all discussion and the points from pacificwing. Thanks goes out to you for the input. Let's hope this works.

You may download it at: http://derekgordon.com/gps-files/beta/acer.iconia.500.test.1.zip

This is based on the Google NO-SSL Build for v3.1. This will supple a customized XML file and the latest LTO file and more. :D

As always, don't forget to do a backup before installing just in case you want to revert.
[Acer Iconia A500] Zoandroid:
What, in laymans terms, does the change to the gpioxxx value do?

So to try this (after a Nandroid) one flashes that zip file from recovery and that is all?
[Acer Iconia A500] crypted:
Right just flash and go. Should have all you need.
[Acer Iconia A500] Zoandroid:
Does a mighty fine job of disabling my GPS completely! :D There are no signs of any sats trying to lock in at all, and the A-GPS tool says it resets or downloads but nothing else happens. Only the compass has any sign of life.

Time to use that Nandroid I just made. :)
[Acer Iconia A500] pacificwing:
That is what the transformer prime patch was doing to me before. I thought I had it nailed with the parameter above. I'll look into it further. Stand by.
[Acer Iconia A500] crypted:
Thanks for researching and playing with this. It's hard not having the device and really deducing the issues especially when they aren't so trivial as most device issues usually are.

I'll post an updated one if we have an idea of what to try next.

I really think that this device is setup to use legacy methods only although it has the hardware for more than that. So, we're going to have a hell of a time getting these new methods to function properly.
[Acer Iconia A500] pacificwing:
A couple of observations:

RfType="GL_RF_47511_BRCM_EXT_LNA"

This is the wrong radio type. Try this instead:

RfType="GL_RF_4751_DANUBE"

That should solve the problem with the GPS cutting out entirely.

I'd also change:

PeriodicTimeOutSec="5"

to

PeriodicTimeOutSec="15"

as the A500 tends to be a little sluggish.

Also, I noticed you're still using the 7 day LTO. You might want to switch to the 30 day version and rename file to lto2.dat for the benefit of future updates. There are actually some GPS assistance apps that will update this file, as I've discovered. They usually use the V2 version.

Just from my own experience, in the gps.conf I find I get more accurate locks with:

ACCURACY_THRES=5000

I get fewer satellites total, and it does add about 2 seconds onto my lock time, but more of the satellites I do get have a higher SNR (in the green on GPS Test). Ultimately, it increased my accuracy from 45ft down to 15ft when I increased this from 3000 to 5000. YMMV.

Hope that helps,

-PW
[Acer Iconia A500] crypted:
Ah, first one makes sense. Changed in Test #2.

Second point, that var allowed for GPS navigation on devices that could handle the refresh rate. Needs a good processing unit to do so. I assume this device lacks that.

Third point, won't touch and let users customize as they wish as always.
[Acer Iconia A500] crypted:
Test #2 is available!

Get it at http://derekgordon.com/gps-files/beta/acer.iconia.500.test.2.zip

Changes made are above in discussion.
[Acer Iconia A500] deboyz1014:
Success with A500 and Thor 156ICS

Version 2 and I was able to find and lock on to about 5-8 sats (fluctuates) within 30 secs or so first time. Second time, about 10 secs then it locked on.
[Acer Iconia A500] crypted:
Cool. Which version are you having success with? And, what are your results?
[Acer Iconia A500] maris__:
Just two notes: a) if lto.dat (resp. lto2.dat) will be placed in /sdcard/Download, the correct pathway for acLogDirectory is presumably "/mnt/sdcard/Download" (not "/sdcard/Download"). b) the sat fix is less fast and stable when lto.dat (or lto2.dat) is moved to Download. Not sure about the reason. Maybe it is just a matter of time, until the number of daily assistance files will have been increased.

Best regards, maris
[Acer Iconia A500] crypted:
Can you test the test #2 by chance? LTO is maintained in the /etc/gps/ structure assuming our problem is /data/gps being cleared as if it were a standard tmp cache directory.
[Acer Iconia A500] maris__:
Sorry, my post was non-sense. Did not realize that you included a separate directory pathway for lto.dat. So I guess this is the optimal soloution. Will test it.

Thank, and with best regards, maris
[Acer Iconia A500] crypted:
No worries. I'm one to keep necessary crap off of my sdcard's as I have a nasty habit of formatting them from time to time. So, I thought we'd just put it within the /system/ structure at a different location than standard.
[Acer Iconia A500] pacificwing:
The parameter you want is:

acLtoDir (read my post above)

acLogDirectory is only used if cLogEnabled is set to true, at which point that directory will end up with 1 .txt file for every time you use your GPS. That can lead to hundreds of log files. I usually give it its own directory:

acLogDirectory="/data/gps/logs/"

Unless you're doing troubleshooting, you can leave logging turned off safely.

Cheers,

-PW

EDIT: Never mind. Just saw your other response.
[Acer Iconia A500] maris__:
Thanks for the clarification. Just did not read careful enough.

@crypted: I am currently testing your new patches. #2 is really incredible!! However, I still think that the complete directory pathway should be included in acLtoDir. When I am changing "etc/gps/" to "/system/etc/gps/", then I will have the most stable fix despite quite difficult conditions here (indoors, concrete multi story building, rainy weather), with constantly 4 to 7 fixes.

Best regards, maris
[Acer Iconia A500] crypted:
I'll make Test #2 the v1.0 stable for this device assuming we get more verification. I'll make that slight change you suggest as well. It doesn't matter on my devices as it assumes /system/ as the root "/" but I guess it could matter in a various isntances.
[Acer Iconia A500] pacificwing:
I don't think it matters. You can see in init.rc (which is called before init.picasso.rc) where the symlink is established long before the gps daemon is called.

The only time I this could pose a problem is well into the future when google stops supporting the old file structure.
[Acer Iconia A500] crypted:
That was my essential point. We ought to be fine to this end.

I hope to get some more responses by the end of the weekend on if Test #2 works.

Assuming there are a few more thumbs up's, I shall proceed with this special version release for the Iconia.

Thanks to pacificwing for all your input and helping me sort through what this device has and has not. Definitely a nearly impossible feat for the time I can devote at this point. :D I appreciate you hopping on the thread for the past day or so.
[Acer Iconia A500] loekis:
Ok, regarding your last post i can confirm a quick fix immediatly after installation and reboot. Still ok after another reboot - it only takes a few seconds. Only thing i don't understand are the altitude values: my phone indicates (correct) 446 meters above sea level, iconia is showing anything between 470 and 505.... But it doesn't bother me at the moment (before applying the patch using R11 original files, altitude was closer to reality).
[Acer Iconia A500] crypted:
Prior tests suggest that the xml altitude latitude and longitude variables aren't worth screwing with. No speed or accuracy benefits.
[Acer Iconia A500] Zoandroid:
I believe your zip2 file worked, but something happened to my tablet which screwed up SU. After trying several times to restore the nandroid I made this morning kept yielding the same corrupt SU (whatever is wrong appears to have happened this morning before I made that nandroid) I had to fall back to last Sat.'s nandroid, which was while still using Thor's HC 3.2.1 ROM. I'll try zip2 again when I get things restored.

EDIT - Zip2 works like a charm while running Thor HC ROM.
[Acer Iconia A500] crypted:
wonderful.
[Acer Iconia A500] Zoandroid:
Well, I am now running Thor's ICS ROM v156, and the Test2 zip GPS fix seems to work really well there too. :)

Thanks!
[Acer Iconia A500] BakaNeko59:
I've tried scripting the download from the site you mention using wget, but it comes back with 'bad address'. Why would it work from a browser but not with wget? Is there an FTP site that maintains a current copy rather than the http site?
[Acer Iconia A500] crypted:
Have you tried test #2 build? It shouldn't require manual downloading I think.
[Acer Iconia A500] CuriousTech:
I noticed this on CM: https://github.com/CyanogenMod/android_device_samsung_vibrantmtd/pull/3

get-gps-lto isn't giving me any errors, but doesn't seem to work either.

The mods to init.aries.rc would be init.picasso.rc on ours, which I'll play with later.
[Acer Iconia A500] crypted:
Downloading the LTO more often doesn't mean you're going to get quicker GPS. Rather, you're getting the almanac more often. And, the almanac is designed to last for several days so redownloading it is irrelevant.
[Acer Iconia A500] CuriousTech:
I have no lto.dat so frequency isn't important to me. :)
[Acer Iconia A500] Zoandroid:
So what happens once you start using the lto.dat file and it's intended duration expires? Would you start seeing longer times needed to lock on satellites again?
[Acer Iconia A500] crypted:
No, it should refresh it just fine. The issue with some ROM's is that the file was being deleted as if /data/gps was treated as a temporary directory rather than a standard directory for an updated file.

So, I changed the file location in Test #2 and included an LTO file to be the placeholder until it refreshes. Again these are tests, but this should be how it works based on what we've seen happen.
[Acer Iconia A500] Zoandroid:
Oh. I did not look into the content of your test2 zip package, so did not know for sure how sustainable the fix would be. So if all goes well this fix will update itself as time passes? That is pretty cool. :)
[Acer Iconia A500] crypted:
If a few assumptions prove correct it should be this way.
[Acer Iconia A500] Zoandroid:
Thanks. Assumptions are always dangerous business, but I hope they work out for us.
[Acer Iconia A500] crypted:
Without owning the device and using the information I've read and discussed with others, I can only make assumptions. But, those assumptions aren't just random. I do have some basis for thinking things through as I have. :D I mean if I didn't, this patch wouldn't work on 24 devices officially and supposedly on another 30+ (haven't sought full out confirmations on those others).
[Acer Iconia A500] Zoandroid:
I keep forgetting you are doing all this without the devices on hand to test your ideas. That must make for some interesting thought processes. :) Thanks again for your work on this!
[Acer Iconia A500] crypted:
No worries. And the thoughts are really just using my intuition, my Linux experience, and my growing knowledge of the chipsets and similarities versus differences in operations for GPS. ;)
[Acer Iconia A500] drharisis:
No quick GPS fix for Acer iconia... I it locates many sats but it cannot obtain a quick fix...both test builds tested.,,,,
[Acer Iconia A500] crypted:
Did you test a couple of ROM's at least?
[Acer Iconia A500] pacificwing:
I was afraid of this. The LTO.dat is out of date. After observing it for a few weeks now, I've noticed the A500 doesn't update it automatically, even when supplied with an existing file.

I've been doing it manually, which with the way I've set it up, isn't that much of an inconvenience. The LTO starts to lose its potency after about 3-4 days.

I've tried moving the daemon binaries from both the ASUS rom and Thor 14.2, and modifying the RC files accordingly. It does run, but it complains about missing support from the kernel and crashes shortly thereafter. It looks like the kernel will need to be recompiled for a proper fix, and this is over my head.

A shell script that runs every few days shouldn't be too hard to come up with. It could be set to run every two days as soon as an internet connection is established. This seems like it would be the only way to prompt automatic updates, but it is a band-aid. I'll play with some stuff and see what I can come up with. If someone with more experience wants to jump in, that would be great.

Cheers,

-PW
[Acer Iconia A500] crypted:
Allright, isn't ICS coming to this device relatively soon? If the updating problem still exists there, and GPS still struggles, I may write an update script to create new flashable ZIP files weekly for this device.
[Acer Iconia A500] ZeroAlphawolf:
Yeah so far it seems to be fine. I dunno, i will keep watching it and trying the map app sporadically, im hoping that it will remain well off, because when it doesnt have that hanging notification it seems to pull my location quicker on any of the location based apps. Thanks again.
[Acer Iconia A500] crypted:
Keep us posted.
[Acer Iconia A500] ZeroAlphawolf:
Hmmm definitely sporadic, it started up again without me even going into any particular map or GPS related app, kind of obnoxious.
[Acer Iconia A500] crypted:
Right now, I am sending you a test build to see how it works on your device. Ignore the name of it.
[Acer Iconia A500] josinpaul:
its superb.I used it for 450km journey, never dropped GPS signel. the first lock in now is under 5 seconds and I am getting locked to a minimum of 4 to 5 satellites. way better than my in car navigation system.

oh and I tried it on my LG optimus one p500 (running cm7 ported) and it works superbly.thanks

:D

I have rated your thread excellent.
[Acer Iconia A500] pimpmaneaton:
I would say maybe try richardtrips kernel and I see you have several weather widgets on your screen, is one of them trying to get GPS while in doors? This could very possibly be your issue, if not to much of a hassle remove any widgets that use location and reboot and see if you "Searching for GPS" ghost reappears. I have runs both thors and richards kernel my preference is richs, but that is just me they both do great work. Hopefully this helps shead some light.
[Acer Iconia A500] ZeroAlphawolf:
I'll try it, it just sucks cause its sporadic, so it can go for an hour or two with no problem.

Then it pop back up.
[Acer Iconia A500] pimpmaneaton:
Also maybe when it does happen hit your windows key(or multitask key, not really sure what it is called, the one just to the right of the home key) and see if any app has started and is requesting gps location. A logcat would also help as well.

EDIT: Where you using thors kernel before the patch? Possibly try his regular kernel if you want to stick with Thor. I have always used the regular one and not "the rest" and has always been problem free.
[Acer Iconia A500] ZeroAlphawolf:
Honestly, using the GPS as little as i do, i'll probably just return back to the normal GPS. I have an Iphone 4, so, finding my GPS by wifi isn't really much of a big deal to me.
[Acer Iconia A500] crypted:
One final question before you pack it in if I may... When using this, were you in range of WiFi? It requires a data connection to work since it's aGPS.
[Acer Iconia A500] ZeroAlphawolf:
The entire time.

---------- Post added at 10:28 PM ---------- Previous post was at 10:24 PM ----------

Though, something from Cry, was the other file he sent me, im still checking it out real quick, hadn't realized i'd had a pm from him.
[Acer Iconia A500] crypted:
If it works, great. If not, well crap. I'm thinking pimpmaneaton is right regarding kernels. I've seen that be a key player on two smartphones recently.

But, he also made a good point about widgets. Not having a tablet, I didn't consider widgets trying to use GPS to ascertain where you're at for their specific output.
[Acer Iconia A500] ZeroAlphawolf:
Well, so far, it seems good! But, i think he may have been right, i had one weather widget up (Weatherbug) and it had Follow Me enabled, i cleared that, and actually told it to stop using GPS, cause well..i only need to find my town once to have it display weather for it.

So it's working again for me.
[Acer Iconia A500] mistahd33:
I have an A501, stock 3.2 rom, and rooted kernal (honeyvillian from memory).

GPS reception on the orignial stock 3.01 rom and then the rooted stock 3.2 rom as well was shonky at best, it would lock quickly, but then loose connection to gps a couple of seconds after it has locked on every time it locks on.. then it may take anywhere between 3 and 60 seconds to reconnect to gps reception.. the result is that when flapping along a freeway at 110kmh, my location is only updated every couple of hundred meters or so if im lucky.. more than enough time to completely miss directions for a turn off.

I tried your patch, nothing changed at all. nothing.. its exactly the same, still looses reception right after it locks on and jerks me along the road at 100m intervals on the gps rather than moving me smoothly (like my htc desire with much the same software installed can do very happily without batting an eyelid).

Frustrating. To me iconia GPS is useless for anything other than getting very accurate weather :|
[Acer Iconia A500] crypted:
Can those of you with this working tell us the kernel you're using? This issue of no luck on the freeway is just silly!

I need to tell these kernel devs what's up! They wont care...
[Acer Iconia A500] mistahd33:
Yeah to be frank, my desire beats the iconia in gps and wifi reception, and 3G reception sometimes 'stalls' on the icona.. all with or without the stock kernal, and my heavily rommed old desire hd was far quicker and smoother than the iconia was straight out of the box.

It makes me wonder if the iconia needs some kind of radio firmware update? (just like we have radio updates for the htc phones)... although I've not heard any mention of a fastboot interface let alone a radio update... thoughts? anyone else think they might agree or are having a similar user experience? or did I just get a bit of a dud this time around?
[Acer Iconia A500] pimpmaneaton:
Yes the gps on iconia does blow but this does help I can guarantee that. Do you have gps status install? If so please open and hit menu and tools and then agps tools. Reset your agps and then download it. After downloaded reboot tab, go back into gps status and with tab standing up allow gps status to sit idle with screen on for about ten min. I say with it standing up because mine can't seem to get a signal at all laying flat but once stood up gets 4 or 5 instantly and then starts grabbing more. You may have to enable keep screen awake in gps status.

Sent from my Sensation Rockin CoreDroid!
[Acer Iconia A500] mistahd33:
ill give that a crack.. ill let you know if it improves.

EDIT: its having a bad night tonight.. I left it for an hour upright in the dock and it found 11 sats but didn't get a single fix... I noticed that after thoroughly calibrating the compass it slowly wanders clockwise after i dock it... at one point it was pretty convinced that south-west was south... could the dodgy gps's in these things be a result of the compass confusing matters? In fact with further playing around i noticed that the dock (official acer desktop dock) forces the compass out clockwise by about 15 degrees as soon as I dock it... the tablet sits in the dock at apparently an angle of 71 degrees.. if i pull it towards me so its nearly 90degrees upright and leaning forward in its dock it looses that extra 15 degrees on the heading again.. if i pull the dock forward at the same time so that the dock is still pressing against the back of the tablet, the extra 15 degrees remains on the heading... I'm guessing the power feed or something running through the backplate of the official acer dock is causing havoc, can anyone else confirm?? .. anyway thats completely aside the real issue, I moved it out of the dock and put it sitting vertically (you're right, it seems to help) on top of the sofa.. as soon as i moved it and walked around with it, it lost nearly all its sats.. its been sitting on top of the sofa for 15 minutes, it can see 8 sats, still no fix... I think i'll abort and try again tomorrow night. :| Just acred up the htc desire to check,. fully locked and stable within 30 seconds. I'm so glad work funded this tablet, I sure as hell wouldnt jump onto the tablet bandwagon yet with my own money if this is how they stack up.

EDIT: it finally found a lock on 4/9 sats after about 30 minutes.. its average update interval seems to be about 4-5 seconds with it peaking at worst at about 15 seconds.. still nowhere near quick enough for the 2 seconds which the gps programs seem to demand. I'll let it go overnight and see if its any better in the morning.. and i'll repeat the process tomorrow.
[Acer Iconia A500] crypted:
Thanks for the update. Sounds like a crazy device to me. To be sure, have you considered disabling or closing all apps and widgets that use GPS and testing with them off? That could ensure you're not having app interference although I'm doubtful it would matter.

Would you mind testing this patch on your HTC Desire? I support DHD and want to bring support to a few more devices. If you try it, just send me a PM with the results.
[Acer Iconia A500] SoHaunted:
Just wanted to chime in and say I installed this on my 3.1 a500 and sitting in my living room I went from getting 0-2 sats on and off to 4-6 sats with 5 being consistent! Even more stats when outside!

What an amazing fix, thanks a million.
[Acer Iconia A500] pacificwing:
That's kind of what I'm waiting for. I don't want to go to all the time of fixing something that Acer may very well fix in the final ICS. If they release the final version and it's still messed up, I'll look into writing a script. Updating the LTO is not too much of a bother.
[Acer Iconia A500] crypted:
Let me know. Maybe we can work together to put together a working script into this package for everyone.

Currently, this works for a number of users but not for others. Could be we end up with a joint development that will work for all.
[Acer Iconia A500] Zoandroid:
The genuine "official" date on which they will "START" pushing ICS to the Iconia A500 is last stated to be 4/27. Hopefully we'll start seeing some action then on getting the update.

I don't know if this will matter in your plans to create an automatically updating utility, but it seems ICS has "abandoned" some longstanding file transfer abilities, most notably being able to connect by USB as a "Mass Storage" device. In so doing, they are seeking to limit which files can actually be copied. I ran afoul of this issue in 2 different ICS ROMs which interfered with my weekly routine of backing up both Internal Storage and External SD. I know there is a project underway here on XDA to restore Mass Storage access to ICS on some phones, but it did not work for me on the A500. Hopefully it won't prevent what you would need to do to keep things updated for the GPS Fix.
[Acer Iconia A500] drharisis:
Does anyone uploaded new stock rom on A500??does it have a gps fix????