yashsingh1/xdaforums huggingface dataset:
[Captivate Android Development] tk44uk:
I agree.

Testing signal strength with the black plastic back on my Galaxy s removed , I find that the GPS signal is noticeably stronger, compared to signal strength with the back on.

Apparently, it's due to the carbon used in the colouring for the plastic...

as discussed here: http://xdaforums.com/showpost.php?p=7448732&postcount=527
[Captivate Android Development] Haloruler64:
Our backing is metal though, not black plastic. Though it does have a black paint on it, not sure if it's carbon though. It's not pure black, it's lighter.
[Captivate Android Development] ewingr:
Interesting. I've noted that having the back cover off makes a big difference, including pretty early in the thread about cleaning the contacts on the back cover.

I've been running mine w/o back cover (using Seido Innocase), on 2-3 different ROMS quite successfully. (Not perfect, of course, but quite livable.)

I have found that the JL3 modem is the absolute best I've used. W/O going into the detail I have many other times, other modems are flaky on WiFi compared to JL3. I have not tested JK4 (I think that's the one mentioned as beeing pretty good also).

I do have the wander past intersetcion, etc, and I have been of the strong opinion that the Google Nav software is a bit flaky. Co-Pilot works much better overall, in my opinion.

I have also been using Jupiter 6 for quite a while, and that combined with the back off is what seems to make it livable for me. I may attempt further changes per the OP in this thread and see how it goes.
[Captivate Android Development] poormkp:
Since the theme of this thread is hard data vs anecdotal, I ran some tests to try and quantify how much signal degradation might be occuring due to the back cover properties. To do this I ran a series of five one-minute tests with the phone in the same location, first with the cover on, then with the cover off. Using lbs test mode I first deleted gps data, then manually recorded the highest signal strength I saw for the next 60 seconds.

The results were as follows:

Test 1

Cover On – High Signal Avg 25dBHz

Cover Off – High Signal Avg 30 dBHz

Test 1 difference 5 dBHz

Test 2

Cover On – High Signal Avg 18dBHz

Cover Off – High Signal Avg 32dBHz

Test 2 difference 14 dBHz

Test 3

Cover On – HS Avg 30 dBHz

Cover Off – HS Avg 32dBHz

Test 3 difference 2 dBHz

Test 4

Cover On – HS Avg 29 dBHz

Cover Off – HS Avg 31 dBHz

Test 4 difference 2 dbHz

Test 5

Cover On – HS Avg 29 dBHz

Cover Off – HS Avg 32 dBHz

Test 5 difference 3 dBHz

Test 1 thru Test 5 average degradation 5.4 dBHz.

While the magnitude of the signal loss varied, the direction was very consistent. While doing this I also observed improved signal strength on the cell radio but do not have numbers to share on those.
[Captivate Android Development] ari197:
nice data .. so it really shows that the back cover has an impact to gps quality..

maybe we can ask samsung to change the back cover ?

quite interesting though, the i9000 has a different kind of back cover but they also experience bad GPS ..
[Captivate Android Development] used2hvatreo:
I haven't taken the time to look yet, but do we know if that 5.4dB actually makes a large difference in the ability to get a lock or get decent accuracy. I know that I have no hard evidence to support my claims, but I have gone from getting no lock outside under the stars on one rom to getting a 10m lock inside about 10s ago with the current rom i'm on, inside of a black case with the backplate on.

I will test and provide datas as well, since currently i'm seeing the best gps performance yet on P9.5
[Captivate Android Development] aleadam:
How did you run those? Always starting with the cover on? I ask because I usually see some improvement over time just by itself. Did you see an increase in the number of sats available? Did the accuracy increase (e.g., from 15 m to 5 m)? Why the cover is relevant? Did you test if with the phone face down? If so, how useful will be this mod in a real life situation with the phone facing you over the car or in a mount?

My apologies if it sounds a little overwheling, but I read this on many threads already and I would love such a simple solution. Problem is, I did not read that real life use improved without the cover. Moreover, with the jpy rom and jl2 modem I can see a very high increase in sensitivity (with the cover on) compared to stock eclair and even previous froyo roms, but many of the original problems in location remained, suggesting that the key to those is in the software/firmware, which is the real theme of the thread, not hard vs anecdotal data.
[Captivate Android Development] used2hvatreo:
i definitely agree with you, i would love an answer that solves the problem once and for all. I have been doing some reading and will continue to research the increase in signal w/ cover off vs actual performance gain. thanks for all of the work you've put in to this already
[Captivate Android Development] yummybar:
Hey guys!

Im really fairly new to flashing roms and kernels but i have some questions if anyone could answer it would be great!

Im running Darky 7.5 ROM + setiron kernel + jl3 modem.

So i just CWM install the plane version of the .zip, and everything should work right away? or is there further modification i need to do?

Thanks!
[Captivate Android Development] ewingr:
Here is a post in another thread on XDA I linked to earlier. I like the way poormkp did his test. I won't reiterate how I did my test, as you can read it on the link.

In general, I felt that tracking and locks were better with the back off. But one other thing that I do find important is the phone having a clear view of the sky through the windshield. I did a lot of tests with that, with two phones. One under roof, other under windshield. Switched places with phones. And both phones performed better than the other when the respective phone was under windshield and the other wasn't.
[Captivate Android Development] askpcguy:
I noticed trying the i9000 rom my gps obtained a lock much quicker. Even going against a stock captivate, I would lock faster and this is with both devices outdoors side by side.
[Captivate Android Development] Shoey Peachew:
Wow, this is great!

I'm coming from an iPhone and when I got my Captivate a week ago I had no idea it had gps issues. I was dissapointed as I sat at home and Navigon never acquired a gps lock, something my iPhone had no problems with. After applying this gps fix, GPS Test app shows I'm connected within 5-10 seconds. Amazingly, every satellite my phone picks up I'm connected to instantly. Also, when I'm driving there seems to be no lag with Navigon or Copilot and where I am physically on the road, unlike my iPhone, which lagged too much and made it useless driving within a city.

Anyway, I almost bought a garmin, but thanks to this wizardry, now I don't see the point. thx!
[Captivate Android Development] poormkp:
Correct - install the .zip with CWM and enjoy the magic.....
[Captivate Android Development] dalewest:
How to backup existing GPS stuff first

Greetings all-

I have no issues flashing a new GPS package, but I'd like to back up the existing one first so that I can revert to it if I need to. Any ideas as to how?

Thanks.
[Captivate Android Development] aleadam:
You can always look inside the zip file to see which files will be replaced.

In this case, three files will be replaced:

/system/bin/gpsd/glgps_samsungJupiter

/system/etc/jupiter.xml

/data/gps/secgps.conf

You can copy your files to the sdcard using root explorer or adb.
[Captivate Android Development] aleadam:
I agree on pretty much everything you say in your post.

It may be my specific experience that the cover off does not really help at all. It may be batch-specific, who knows really? Although my gps was never good, I never was one of those that would not get a lock at all, even in stock eclair. Maybe we have different covers.

Taking the cover out does not reduce the sensitivity either, suggesting me that the contact to the cover is not really needed either. My cover is quite worn at the contact site, so it should be making a good contact, if required.
[Captivate Android Development] ewingr:
I guess I'm dense today.

I've ready through (albeit somewhat of a skimming mode), and don't see anything in the OP that definesspecifically what the difference is between teh 3 zip files there for download. I gathered that the *att.zip one is for those on AT&T network, which I am.

Is that the one I should use? Or more specifically, if I do a bunch of testing and try to do the logging, is there any reason to apply either or the other two?
[Captivate Android Development] aleadam:
If I'm correct, the differences are for agps only. They should not affect tracking, which is the most relevant part of the rest of the changes. I'm using the at&t version.
[Captivate Android Development] yogesh892:
hey did any of you guys get a chance to look at the physical fix on the vibrant?

http://xdaforums.com/showthread.php?t=878970

seems rather promising
[Captivate Android Development] dmshaefe:
Saw the vibrant fix...

Hey I saw that fix too, we have a thread on a similar fix.

http://xdaforums.com/showthread.php?t=876179

Seems our phones do not need to be ripped apart quite so much to get to that same contact. From our thread, it seems like it boosts signal strength all around (cell and gps) for a few days at the most, and then the metal falls back to its original, unbent position which leads back to the performance before the fix. Some even broke their metal piece so I have been hesitant to try it. It seems if you could get that metal piece to stay where you bend it then you might be in business.

Da_G's fix has done wonders for me for inside locks, haven't had a chance to run anything on the road yet. Kinda holding off on any hardware hacks until I see how this performs. I am trying to see what each fix does individually to see if anything actually helps. Cog 2.3b8.
[Captivate Android Development] poormkp:
Agree - I'm having really good tracking success with the google version. Tried the att one, was not quite as good for me. Have not tried the control plane yet. Had two routes yesterday both with excellent tracking so I'm pretty enthused. I think the implementation differences with the three versions would be lbs test mode adjustments to optimize with the servers...?
[Captivate Android Development] BillShepp:
I've installed the att.zip via CWM and verified that the files are updated in the expected locations, but when I go to LBSTestMode the settings are still my old ones. I'm running an older version of Cognition with Eclair. Any ideas why the change wouldn't take?
[Captivate Android Development] poormkp:
I think the lbs test mode settings are still user controlled so you would choose the settings that work best. Da_G posted the ones he is using on page 1.

Using the google version, settings that are working for me are supl.google.com, port 7276, secure...off, accuracy 200. Definitely make sure to set to standalone.
[Captivate Android Development] aleadam:
I'm pretty sure this files are for froyo roms. He was looking into eclair roms but I don't remember any file around.
[Captivate Android Development] rfarrah:
Just want to say thanks to Da_G and others who are diligently pursuing this fix. We "little people" appreciate it! :)
[Captivate Android Development] dmshaefe:
Little bit of testing results

Hey guys I just got out and tried the att.zip one with cog 2.3b8 and it is amazingly better than anything I had before. The GPS for me used to be decent, but it would put me off on side roads when I drove by, change my position several times and repeat directions when stopped at an intersection, little annoying stuff like that. Now all that is gone and it is very usable.

I just drove about 20 minutes and when I took a different route it rerouted me within probably 2 seconds and it recognized when I turned in about the same amount of time. Before it would "hang" when I would turn, sometimes causing me to miss my next turn but that is not an issue on this.

I cannot say for sure because I still need to check long term compatibility and maybe try this on the new Phoenix rom that adamholden85 is working on (axura2.6) but the net result seems to be real-world usable GPS. Using google nav by the way. Thanks a bunch Da_G! :D
[Captivate Android Development] ap1618:
I tried both the att version and the google version.

both of them as soon as the GPS runs, it turns off like in 2 sec. what's wrong?

thanks
[Captivate Android Development] ari197:
I've read somewhere in this thread that this is because the GPS daemon died. Could be because you are using an incompatible ROM.

What ROM are you using?
[Captivate Android Development] ap1618:
actually I fixed it. there is a code change posted in the OP for Eclair ROMs. but accuracy doesnt seem to be good now.
[Captivate Android Development] hostilebynature:
thanks brother. all i did was was flash the plane one and i didnt change anything else at all, and it locked in on me pretty quick. pretty accurately too. like within 2-3 houses, im sitting in my flat appt atm.

amazing.
[Captivate Android Development] TheYar:
Tracking is the main focus, I believe, as opposed to locking.
[Captivate Android Development] rfarrah:
I would have to agree.
[Captivate Android Development] ari197:
just wondering .. what cause satellites to be in view but not locked?

the reason I asked is that sometimes I found many satellites in view (6 or 7 of them) but none of them get locked ..
[Captivate Android Development] ap1618:
ive seen that mostly when using standalone...
[Captivate Android Development] ari197:
oke .. but what cause it? just doesn't make any sense to me..

anyway, if not standalone, what do you suggest I use? the OP suggested using standalone
[Captivate Android Development] Haloruler64:
Installed the Google one. I live in an area where signal, GPS, everything is bad. So I can't lock indoors (I did only twice, not sure how). But when I went outside I got a lock to 9 sats in literally 6 seconds on a fresh boot. Accuracy went down to 30m eventually, pretty impressed! Not sure why it didn't go to 15m, it used to on Perception 8 with JM9 fix. Not as fast though.
[Captivate Android Development] itchytweed:
Finally found this thread again and bookmarked it so I don't lose it. Now to see if it helps. I have my Craptivate on Google Maps sitting on my table here in the kitchen and watching it bounce from home to the cellsite back to home back to the cellsite ad nauseum.

Da_G: Your posting is excellent!!! The breakdown of information belies your talents. :D
[Captivate Android Development] hyperpuma:
With this fix I went from seeing only one satellite and getting no lock to 7 with lock after 12 seconds while indoors. Accuracy is 30-50m but hey it beats no lock. Cheers.
[Captivate Android Development] itchytweed:
Running Craptivate with stock software but rooted.

Edited jupiter.xml using Da_G's OP info. Restarts vary from 15 to 30 seconds. Running Google Maps has the pointer 1-2 seconds behind where I am at (expected) but updating once a second. No wild movements noted but at a standstill, the compass takes over on the map and the pointer may turn around in place. Once I get moving, it corrects itself. Cornering showed no overshoot or wildness, even when I did a couple of snap turns - the pointer was correct at the next update w/o overshoot that I could see.

When comparing position on the Craptivate vs. Garmin Rino 530HCX, they are just about together (within accuracy) and the phone floats about +/- 14 meters.

Here are the relevant sections to jupiter.xml:

<hal

acPortName="/dev/s3c2410_serial1" lBaudRate="115200" cLogEnabled="false" acLogDirectory="/data/gps/log/" ltoFileName="lto.dat"

enhanced-assisted="false" cp-enhanced-assisted="true" TISEnabled="false" RILEnabled="true"

acEEDir="/data/gps" acEEFileName="xtra.bin"

arp-supl-enable="true" arp-supl-cap-msb="true" arp-supl-cap-msa="true" arp-supl-cap-ecid="false"

acSuplServer="www.spirent-lcs.com" SuplPort="7275" tlsCertPath="/system/bin/gpsd/supl_att_root.cer"

LbsEnable="false" LbsLocal="true" LbsSyncLto="true" LbsSyncCells="true"

acNmeaOutName="/data/gpspipe"

gpioNStdbyPath="/sys/class/gpio/gpio121/value"

gpioNResetPath="/sys/class/gpio/gpio120/value"

ctrlPipe="/data/gps/glgpsctrl"

lcsApiSockName="/data/gps/lcs.socket"

acNvStoDir="/data/gps/"

/>

-----

<job id="normal">

<task >

<startup ignore_osc="true" ignore_rom_alm="true" ignore_nav="true" ignore_pos="true" ignore_ram_alm="true" ignore_time="true"/>

<features enable_low_power="false" sbas_priority="true" enable_low_power_ext="false" />

</task>

</job>

------------

LBSTESTMODE is set for standalone and a quality of 200.

What is interesting is that with "sbas-priority" turned on, neither GPS STATUS or GPS TEST show them showing up, not that it seems to be needed.

Now the Craptivate seems to useful in this department.

Thanks again.
[Captivate Android Development] jamesyl:
Seconded. Plato posted with some additional info about the Vibrant but I didn't see any other posts from Vibrant users. It seems the Google daemon should work on our Vibrants. I may give it a go when I have spare time.
[Captivate Android Development] acdbx:
Sounds great that you got it working. What was GPS performance like before?

Can you explain why these settings would work, or where you got them? Thanks!
[Captivate Android Development] itchytweed:
GPS performance was: Lock for three-four seconds, lose lock for 5-8 seconds, repeat ad nauseum.

GPS perfomance now: 6/6 - 9/9 satellites and not dropping lock at all. Location error is +/- 15 meters or thereabouts when compared against a Garmin Rino 530 HCX right next to it doing positioning averaging, which for being inside of a house is not bad at all.

Where I got the information: 1) My original jupiter.xml file, which I modified, and 2) Da_G's original post at the beginning of the thread. Just combined the two appropriately.

The phone is still stock AT&T Eclair and rooted for access.
[Captivate Android Development] jaxf250:
Thanks for sharing what worked for you - I edited my jupiter file as you described and will test out this week while driving. Getting more visible sats indoors than I ever have before... even if it's remotely close to the track I am on I will be happy - prior tweaks have yielded below average results thus far, so willing to try anything.
[Captivate Android Development] know8677:
I know I'm going to get slammed for this incredibly dumb question, but how exactly do you install this?

I just rooted my Captivate a week ago and have tried the Cognition Rom and Darky's 7.8. I like Cognition better, but the GPS on Darky's actually works great on my phone but with Cognition it doesn't work at all.

Sorry for being such a noob, but if someone could tell me exactly how to do it, I'd really appreciat it.

My guess is to put the .zip file on the phone (probably the ATT one, but maybe the generic one) and install it using Rom Manager. Since I'm not sure, I do not want to screw anything up.

(I did read/skim through about half of this thread without seeing the answer).
[Captivate Android Development] rfarrah:
Yup, that's it. You could put all three on your phone and test them all until you find what works best. Do a nandroid backup first, just in case, and copy it to your pc. Good luck!
[Captivate Android Development] know8677:
Thank you. I've tried control plane and google so far. Google seems to work OK, but I haven't gone outside yet.

The ONLY thing I did was install them from ROM manager - I haven't made any other settings changes.
[Captivate Android Development] poormkp:
I can't tell for certain, but reading the first page of the Darky 7.8 thread it appears that Da_G's fix is already included in that ROM. There is a credit to him that says "Da_G for his magical GPS fix".
[Captivate Android Development] know8677:
And that's exactly why I found this thread.

With Darky, the GPS works great on this phone.

With Cognition, the GPS stinks

Therefore, I wanted to keep Cognition - which I like better - and the good GPS and that's why I came here.

It appears to have worked.
[Captivate Android Development] Dani897:
Da_g i am now using eugenes ginger clone. i believe it is vibrant based but not sure what build. i installed your update.zip control plane settings and changed some settings in lbs test mode,(i tuned off gps plus and dynamic accuracy) well i cant reproduce the eratic behavior on this rom, maybe it is random, maybe i have a unique phone, but i ran mytracks along with lbs test and got acceptable results with either one int the foreground. the rom is built from a samsung rom but appears as aosp, eugene took the themeing to the point of removing the status bar toggles.

i ran my tracks behind google navigation which has been the primary problem for me and the tracking was impeccable. maybe a fix lies in this build? though i dont know the build it is based from.

maybe available ram has something to do with it? on this rom i often have 200mb free!

i hope you can find a true fix that we can implement on any rom, and i hope that i wasnt just lucky, the skies were clear so reception was great, i wanted good weather to eliminate that as a variable but now i wonder if it is an interference issue is a weaker signal allowing the interference to push it over the edge into instability? it is not set in my mind yet that my gps is fixed and ill report if i have future problems.
[Captivate Android Development] TheYar:
I apologize that this post is not hard data, but I do want to at least document a hypothesis here that I intend to test when I have some time, in the hopes that others can add data to mine.

I don't which ROM or app version I was using, or if it was some setting, or time-based, but I do recall that the very best trip I ever had with the GPS, where it tracked me nearly perfectly, only slightly losing accuracy when around obstructions, was also the only time I noticed that the Navigation app was using a completely black background rather than the usual white for some reason. This was also without any GPS fixes in place.

After seeing so many posts about GPS failing with Nav or MyTracks running, but working well with Test Mode in the foreground, the theory I'm getting at, that I want to test, concerns the possibility that the AMOLED is affecting GPS. IIRC, the foreground apps that are reported here as not causing problems are also ones that use a lot of black.
[Captivate Android Development] n19htmare:
My evaluation with the GPS....

I'm certain that it's the hardware issue, design issue or something similar.

Yesterday, I decided to test the Google Navigation.

The phone was on my lap and I could not get a signal, then I moved it to the dash and instantly, I had GPS lock and tracking was PERFECT on the gps.

I then moved the phone back to my lap, lost GPS in 5 seconds.

Moved it back to the dash, within 5 seconds, had a lock and was tracking perfectly again.

I now held it and it lost GPS.

I did that 10-15 times and everytime I held the phone or placed it on my lap, it lost GPS. Everytime I layed it down on the dash, it had perfect GPS.

In my opinion, the GPS is flawed by the hardware. Not necessarily the chip, but maybe the antenna (the back plate acts as the antenna i believe).