yashsingh1/xdaforums huggingface dataset:
[Captivate Android Development] CuriousTech:
No worries PlumbBob... err, Ryan. Got system restore points or could drop the extra files from the original rom in the zip and flash back. It doesn't appear to be any different than 1.0 was though. I figured it should be different in some way.

With 2.0b1 it seemed to consistantly reaquire a fix during 2 days but took a little longer as the hours went by as if it's reverting back to that first valid state instead of keeping the valid state updated. Notably with the first fix being 30+ secs (which would indicate it's not using AGPS or failing to plug the data in) then the longer delays as the sats move further from that first position. My guess would that there could be a problem with these files on this hardware that keep it from writing the state to the hardware to hot start it each time.
[Captivate Android Development] Soccer_Dad:
I've been a lurker on the PB stuff for a while. For my captivate, the 0.84 beta was best, but I think I get slightly better from the Adams fix - 1.0 just didn't work with Paragon/Serendipity/Onix for me. But I love the idea that someone is actively working on this issue.

I would like to comment on the issue of, well, what the actual issue is here. I find that I can get low TTFF's in a variety of ways, but that isn't really what I care about. What I'd like to do is maintain that fix. In my basement last night, and driving to work in rain today, I got pretty immediate 9/9 fixes. But then my Captivate loses the locks, and I struggle with 3-5 of 8 or so. Are there fixes to this issue, or am I fairly unique in having this problem?
[Captivate Android Development] mbc663:
Jq1......2/2 sats

Jk4.......7/7 sats in half the time
[Captivate Android Development] jsmith8858:
Not unique at all, the main problem is tracking, not initial locking, though some people do have trouble with both. It is a little frustrating seeing so many "wow, GPS locks in 5 seconds, it's fixed! " posts, since that's not the problem, it's the tracking, and people rarely test or report on that when evaluating or presenting GPS fixes.
[Captivate Android Development] iXNyNe:
Have you tried any other modems?
[Captivate Android Development] CuriousTech:
That could be more do with view than anything. Remember, it needs an unobstructed view. Not directly up or to one side, but all the way around. There may be one at a 45° angle to the north, another at 50° EWE, and it needs at least 3 to get a 2D fix and 4 to get simple 3D and better DOP with more.

You'll also noticed that signals are much more erratic when stationary than when moving, but think of it this way. You only need a location and as quick as possible for convenience. Continuous updates aren't needed unless you're moving.
[Captivate Android Development] kodos96:
Holy crap, my GPS works!

I just flashed 2.0beta4 before leaving work, and drove home with it.... and for the first time since I've had my captivate, I made it through an entire trip between home and work without the nav screwing up a single time!

These are dramatically better results than I've gotten with any other fix... it actually seems FIXED instead of just tweaked a bit.

Unfortunately I forgot to delete my gps data before flashing, so I can't vouch for whether or not the AGPS update issue is fixed, but I'll try that next.
[Captivate Android Development] Rrryan2:
v2.0b BETA 4 UPDATE 3/28/2011

Beta 4

- reverted name of LTO (long term orbit) filename setting in gps.xml to stock lto2.dat

- changed LBS sync threshold days from 1 to 0 to force updating esp. on new installs

Beta 3

- typo bugfix to launch script. Thanks to kodos96 for the spot.

Beta 2

- updated driver from the new JVK (Gingerbread 2.3.3) release. All the other GPS files are the same between JV1 and JVK.

MD5: f4e99eed282a329c218e81bca55e5af9
[Captivate Android Development] Rrryan2:
Hard to say for certain after the fact and in some ways this is so much speculation, but another possibility is that the lto.dat extrapolated ephemerides were aging and getting less and less useful.

From Broadcom's website: Long Term Orbits (LTO)

LTO delivers orbit data for 7 days in advance, in contrast to AGPS data valid for only 4 hours. LTO enables AGPS benefits when no network is available, as long as a network has been available in the prior week. Building on WWRN and AGPS Server technical leadership and proven history, LTO has been in commercial operation since 2002.

Essentially, Broadcom smooshes the ephemerides through their own algorithm to predict where all the birds in the constellation will be over the next 7 days instead of just 4 hours. But the longer it's been since it's been updated the less accurate and helpful it is, and the worse TTFF gets...
[Captivate Android Development] Rrryan2:
Mobile tracking is really the major problem for most of us and you're not at all unique. Even my base JF6 could get a stationary lock reasonably quickly, just couldn't track for crap on the move.

There are a number of contributing problems, much of which is covered on the first page of the thread. Rain can be a challenge for all GPS devices too, and these just don't have a very sensitive antenna. And don't forget that getting a lock in a basement AT ALL is impressive already for any GPS device.

In retrospect it might have been a mistake to switch to KB1 based files when it came out, as .84 was really working quite nicely. I think I had assumed KB1 was the latest and greatest and the best choice for Captivate somehow when I should have realized that AT&T had held it up so long it was actually relatively outdated. But with the JV1/JVK Gingerbread base in the 2.0 betas I'm getting the best tracking I've ever had. I've only taken it on 15 min trips and such so far but haven't lost lock yet.
[Captivate Android Development] CuriousTech:
Very interesting! I hadn't seen that before, thanks. I always assumed it was possible since the speed of the Earth and orbits are a constant as well as time, but calculating exact positions and trajectory are the difficult part since they aren't in the more simple AGPS data. Not that I gave it much thought but being even LTO is only valid for 7 days, I think it might give me another headache LOL.
[Captivate Android Development] Soccer_Dad:
One of the things I'm involved with is a cooperative project to map the trails in the NW using GPS. For now, the resulting files are only being compiled for Garmin units (I have one), but I like to contribute to the project when I'm out biking or hiking and find a previously unmapped trail. I am also pretty proficient at map reading, and bike/hike with an altimeter watch, so I don't generally need a single fix - what I want is tracking.

For me, five minutes to first fix, but dead on tracking afterwards, is much superior to a 3 second lock and then lost tracking.
[Captivate Android Development] Soccer_Dad:
The rain was just what the weather was. I was pretty happy getting any lock.

But I test in the basement and on my kitchen table precisely because it can be a challenge. I suspect that most GPS fixes will work on the top of Mount Rainier on a sunny day. I would think that an evaluation of different options when you are seeing 12 clear satellite signals wouldn't be as useful as one where the signals are weak and fewer.

Besides, I will want to get a fix on a hillside covered with trees at some point (technically, last Wednesday, but that failed for me when I could only get 3 sats) and I need to figure out what gives me the best shot with my hardware.

Thanks for your work on this.
[Captivate Android Development] Soccer_Dad:
One other thing to think about. Thanks to the new CPU Spy app, it's easy to see what kind of CPU use you are getting out of any phone activity. I reset the meter, and checked my time in state while running the GPS Test app. My results are shown below (I ran the test for about a minute). Note that nearly all the time is spent in the 100-200 Mhz range (the other frequency states were probably used more to switch screens, to get to the GPS Test app, and to start it rather than to actually run the app).

There has been some suspicion in the GPS threads that maybe there's not enough power, that it helps to have the unit plugged in when running. I'm wondering if the fact that a lot of us have those lower states severely undervolted is adding to our issues. I don't know how the hardware works - whether the power issue is to the GPS chip, and the low voltage to the processor has no effect on that, or if it could be an issue.

Any thoughts?

Edit: Wow, I'm thinking I'm seeing a noticeable difference in lock quality after 90 seconds, with my phone on a single 100mhz voltage control 3 state, between having no undervolt, and having my (up to now) customary -125 mv undervolt. See if any of you get the same results please.
[Captivate Android Development] CuriousTech:
If you really need reliability, something like the QStarz BT-Q890 would help for sure. It's a small one. I have a GlobalSat and don't know of a small Garmin unit. But then it's another gadget to carry around and recharge. There's a little app that redirects it to all the apps so it works like it's built-in.

Just an alternative if the fixes don't work out well.

For me, 1.0 is working out well. Haven't tried beta4 yet, but the worst place is the house. Could be all the electronics. I have a lot in the car too with a PC, GPS, WiFi and 14 USB devices wired throughout and it's actually better. It could be sensitive to nearby RFI. It wouldn't be surprising. But if you're having trouble on the trail that wouldn't be it.

When you're out in nature check with GPS Status, GPS Test, or LbsTestMode to see if it's just getting a few sats or if it's jumping around between 8-10 of them. Mostly when it's having trouble I'll see quite a few but the signal levels jump around so much that it can't hold a fix. If it's only getting 4 or less it probably will only be slightly better with another receiver. Oh, and if it's only 1 directly north it's messed up. That happened to me a few times with 2.0b3.
[Captivate Android Development] Liv33viL:
You bring up a very viable point with the usage of under-volting and GPS signal sway. That would definitely be something to look closer into.

At least from a standpoint of not going for for optimal OC/UV settings for the processor, but rather run the standard voltages with a floating processor and find the medium point or a control point to work from.

Then while sliding through the OC/UV scale additionally make notes of SNR, TTL, Consistency in lock and so on.

There is much involved to doing this with the promise of a "realistic" result as to a controlled environmental test "at the desk".

This may be something I would be interested in testing over the next week or so, maybe less - time permitting.

From here it may be possible to at least gain "some" insight as to whether or not the under-volting issue plays a major factor in a lazier GPS overall.

On another plane - I am still currently on PB 1.0 Final - Stock Voltage KB1 Modified Processor and Slightly modded KB1 modem. My device is working phenomenally across the boards, even with a nandroid backup I don't want to ruin it.

I guess when I start getting board and decide to go scouting for some more horsepower, I'll continue my tweaking then.

Something to sleep on...

Peace-
[Captivate Android Development] kodos96:
If the theory is that the GPS transceiver gets power starved, wouldn't undervolting the cpu help, since it leaves more amps available to the gps?
[Captivate Android Development] dalewest:
Settings via LbsTestMode for v2 BETA 4?

Rrryan2, I've seen a few posts back that you said that you decided to use 50 for accuracy for this beta. Is there anything else we should be changing for B4 beyond what's in the OP?

Great work, btw, and many thanks!
[Captivate Android Development] momulah:
Darkys 9.4 captivate edition....v2 beta 4.....very good initial results still have to track though...here in the plant I work in.....inside my truck in windshield area initially took 66sec to lock 11 sattelites with 50 meter accuracy....then afterwards each following test I got in like 2sec same 11/12 satellites but with 10 meter accuracy....in maps I get 30meter accuracy on position without moving...no blue circle around position at all....so can't wait to test on the way to the hotel...
[Captivate Android Development] D12AKO:
Will be a Guinea Pig...LOL Again!

Good to see that you're still trying to milk the dead cows tits...LOL Will try and help as much as I can with the testing. Passed by last night at your IRC but with no luck... all alone...LOL Finally got a reply today from nemchik... woohoo :D

For those of you really interested in Testing... you really should check out his IRC channel... it's already at Beta 6 over there. Not recommended for the average user. If you're not comfortable with testing and failing then stick with PlumbBob GPS Fix v1.0 for now.
[Captivate Android Development] Rrryan2:
v2.0b BETA 6 UPDATE 3/29/2011

Beta 5-6 attempt to get the download of lto.dat working properly. Incorrect socket configuration was preventing it from happening before. Stupidly, I hadn't realized that by having GPS Aids installed, GPS Aids was externally forcing the download of lto.dat at boot, masking the problem that the native configuration wasn't allowing it to happen organically. This also might explain why it worked wonderfully for some users and not at all for others.

Changelog:

Beta 6

- additional tweaks to pathname for socket. Download of /data/gps/lto.dat now working properly.

Beta 5

-corrected socket name in gps.xml

Beta 4

- reverted name of LTO (long term orbit) filename to JV1/JVK stock lto2.dat to restore automatic AGPS updating

- changed LBS sync threshold days from 1 to 0 to allow on-demand updates esp. on new installs

Beta 3

- typo bugfix to launch script. Thanks to kodos96 for the spot.

Beta 2

- updated driver from the new JVK (Gingerbread 2.3.3) release. All the other GPS files are the same between JV1 and JVK.

Installation instructions:

1. Apply the settings in LbsTestMode as described in the OP if you haven't done so already.

2. DO

NOT

DELETE GPS DATA. While deleting GPS data was a handy and reliable way to force a clean download on previous versions, the new drivers don't seem to recognize when the GPS data has been deleted through external means.

3. Flash the fix.

4. Enjoy.

md5: 8f4691bb04d5931ba77458899b4c0512

BETA 6 Withdrawn, update to follow shortly
[Captivate Android Development] Rrryan2:
Lol, what are you, trying to quiz me? ;)

Actually, your test is not a good approximation of what happens when using the unit for actual navigation instead of just running GPS Test. During navigation there's lots more going on, everything from downloading and rendering the map tiles to text-to-speech synthesis for directions. These things involve a lot of radio, cpu, and gpu activity. GPS test however just puts a miniscule load on the cpu for processing the GPS signal and drawing the 2d bar graph.

Yeah, pretty much. Undervolting reduces the voltage to the CPU only, not the whole unit. From that standpoint undervolting should really make more juice available to the GPS, GPU etc. Whether the extra 25-100 mV really makes enough of a difference though is beyond me.
[Captivate Android Development] anneoneamouse:
Rrryan2,

The directory structure, and files included under \system\vendor\bin seem similar to those found under Adam's GPS fix (albeit in a different location). I thought that your approach (at least for version 1) fundamentally differed?

I'm not poking holes, and no offense is intended, just curious.

Regards,

AoN
[Captivate Android Development] Rrryan2:
Of course the structure is similar; it's making modifications to a pre-existing file structure.

Run an the glgps_samsungJupiter is indeed wholly new, ported over from JV1 Gingerbread 2.3.2. Run an md5 on them and compare if you don't want to take my word for it.

The /vendor folder and the launch scripts are wholly new, required for the new daemons etc. The .so is a completely new one from JV1 as well.
[Captivate Android Development] wgarrido:
Omg omg.... lock took awhile but once it locked..... tracking was the best I have ever seen. Drive home and it was right on and my speed was the same as my car gps. I am using beta 6. I will see if locking speed improves.
[Captivate Android Development] rajendra82:
Is 2.0 beta 6 unchanged from what was on IRC. I downloaded it earlier today, but after I flashed it, my phone would get to the home screen and soft reboot, staring with the bootanimation.zip. If it survived that phase, when I would start the GPS test application, it would reboot after starting the application. My last experience with the fix as beta 4, and it did not do this. I reflashed 1.0 final, and everything is well again.
[Captivate Android Development] CuriousTech:
I think I found one issue with 2.0 that was keeping it from working on mine. When I installed, I think it was b3 that didn't work, I was in a spot that gets no reception. Just installed b6 and it worked. Took it back to the spot with no reception and rebooted, then went out and it didn't work again. It looks like the GPS is opened by something at boot and probably initialized with this new LTO data and since it can't hot start, it gets invalidated. That doesn't explain why it's completely dead though, but I might take the script out of init.d just to see how it does.
[Captivate Android Development] Rrryan2:
There are some trivial differences between this and the version that was posted on IRC like to the version# listed in the install script, but it's essentially the same. That is a bizarre problem and I'd suspect a bad download and/or flash. Download the new one, check the md5, and flash again.
[Captivate Android Development] rajendra82:
Flashed this version without the same issue, The only thing different was I had renamed the jupiter.xml file last time right before flashing, thinking 2.0 betas no longer used it, and relied on gps.xml instead. Is it possible it is still somehow being used in 2.0 beta 6, and not having it there caused a reboot upon GPS access? I had checked the zip file from the IRC beta 6 for contents before flashing (not md5 sum), and everything seemed to be in there. I had also flashed it a couple of times over, so probably it was not a bad flash earlier. You might try renaming jupiter.xml, and reboot, and see what happens.

After the current beta 6, I get locks reasonably quickly, but not as quickly as with 1.0 final. The locks also don't seem to get down to 5m quite as quickly. On my phone GPS has always been pretty decent, with only rare mobile tracking glitch, except when I drove through North Georgia mountains last fall. That time it just could not keep up with all the hairpin bends and lagged pretty bad, showing me way off the roads.
[Captivate Android Development] Rrryan2:
It's a possible in the sense that it's not impossible I guess, but I think it's unlikely. If nothing else there probably shouldn't have been the problems with the flawed socket configuration in b1-b4 if it was still looking to Jupiter.xml for the configurations. My money is still on a corrupt download or a bad flash in your case.

That's about what I'm seeing for the first lock at least. The first lock seems to take <30s, but thereafter subsequent warm start locks are are often stupidly fast. I've even had a few 1sec *indoor* warm start locks, down to 5m in <10sec or so.

Tracking on 2.0 is the best I've seen and others report similar results. I haven't had the occasion to try it for more than 15-20 min or so at a stretch yet, but I haven't lost lock yet. Frankly as mobile tracking was really the most important issue WRT real-world usability I'm pretty happy with such a small tradeoff.

Mountains can be problematic in an application like this. Not only are there a lot of reflected signals that can cause multipath challenges, but remember that unless maps data for an area is already cached locally the application might struggle to keep up with downloading the maps if data connection is poor.
[Captivate Android Development] bobapunk:
I had 1.0 installed. I just cleared gps data, left all the other settings the same, and flashed 2.0. Now I cannot seem to get a lock at all...

Any thing I can try?
[Captivate Android Development] Rrryan2:
Make sure the setting to LbsTestMode are correct, make sure GPS is enabled, and reboot the phone. If you still can't get a fix after rebooting, check and see if /data/gps/lto.dat exists and if so what its age is.
[Captivate Android Development] Yuna:
Rrryan2, i am user of Serendipity 6.2 and i must say i have WORKING gps. But i firstly grabbed jupiter.xml and some other gps-releated files from andromeda. after flashed 1.0 - working, fashed 2.0 - not working.
[Captivate Android Development] Harveythedog:
No lto.dat to be found on my phone either (Cog. 4.1.1 - with a few PB versions having being flashed previously) running beta 6?

Takes 5 minutes for first lock (AGPS not working I guess) but after that performance is pretty good, tracking especially.

Great work Bob......Sorry Mr Plumb :)
[Captivate Android Development] Yuna:
GPS Aids can't too download lto.dat :( something wrong with ginger drivers...
[Captivate Android Development] akuru:
Just upgraded from 2.0b4 to 2.0b6, couldn't find a file named lto.dat under the /data/gps directory either. Here is the whole content of my /data/gps/

-rw-rw-rw- system system 3030 2011-03-30 17:52 gldat.sto
srwxrwxrwx system system 2011-03-30 17:47 lcs.socket
prw-rw-rw- system system 2011-03-29 18:08 glgpsctrl
-rw-r--r-- root root 445 2008-08-01 15:00 secgps.conf

Though it feels slow, 2.0b6 seems to work for me. I'm able to get a fix in ~30 seconds. It is still something if we consider I couldn't get any fix with 2.0b4 and still have a missing component at 2.0b6 :)

I remember deleting data before installing 2.0b4, could that be the cause of missing lto.dat file? And, is there a solution to make the driver to download this file?
[Captivate Android Development] wgarrido:
I have a really hard time getting a lock. GMaps wouldn't so I ran GPS Status and then once that locks go back to Gmaps and then it tracks great. Either way lock took a few minutes. Other than that I am stoked at how well it tracks, even with a small blue circle.
[Captivate Android Development] bobapunk:
Thanks Ryan,

This morning I opened up telenav and let it run for a while. Then I popped over to LbsTest and got a <10 meter accurate lock in about 30 seconds. Then I drove to work with airplane mode on and telenav stayed locked the whole time. Google Nav, however, will not hold the lock when driving.
[Captivate Android Development] kodos96:
I tried out beta6 last night, and performance seemed basically unchanged from beta 4 - i.e. excellent tracking, no erroneous road snapping etc.

I never deleted my gps data though, and my lto.dat is still timestamped to the 27th (before I first flashed 2.0) so that means I'm not getting updates to it, right? Does that mean that after it expires (7 days?) my performance is going to start degrading?