[Captivate General] Dani897:
i went on a few drives today to test out my gps, the odd thing is i couldnt get it to misbehave in a significant way. i am using eugenes ginger clone and da_g's update.zip using his own jupiter.xml. i chose his control plane version. i also used some files from jj4 not because i thought they were better but because i was experimenting with the jm9 "FIX" files but wanted to revert back and grabbed the wrong ones from my computer.

my lbs test settings were:

Sesssion Type: tracking

Test Mode: s/w Test

Operation mode: Standalone

Start mode: Hot start

GPS Plus: OFF

Dynamic accuracy: OFF

accuracy: 50

Logging: OFF

supl settings:

server: supl.google.com

port: 7276

secure socket: off

agps mode: control plane

"use wireless networks" in setting>location and security, was not selected

i ran several my tracks trying to recreate the situation described by Da_g where the gps position jumps around and locks are lost when mytracks is in the foreground and lbs in the background but is accurate in the opposite situation. i wanted to see if any "fix" would help this situation, be it a modem file or gps library from other rom but could not create the unstable situation observed by others. this bugged me because i have had serious trouble with google maps acting erratically while all my stationary tests come out fine. the problem is i never used the gps on this rom and did not know if it suffers from this problem in the first place.

it appears this rom does not have that particular problem or the problem is not predictable or can not be caused at will.

i ran a few my tracks with jm9 files. the results were mediocre at best, did it help? nope

did it hurt? maybe, not sure but probably not.

then i ran the test with jj4 files. did it help? maybe but probably not, tests did appear slightly better but were not free of imperfections

did it hurt? nope

on each test i ran one my tracks with mytracks in the forground and lbs in the background then another with lbs in the foreground and my tracks in the background.

observation: phone did not lose gps signal upon starting any app or switching to any app like others reported. tracking results were too close to call. i used similar routes with clear skys and the accuracy was similar when compared on the same road. with lbs up front i could watch the reported accuracy, it mostly jumped from 10 to 30m occasionally hitting 5, and spending more time at 10. average was about 15meter accuracy.

then for s's and g's i ran my tracks behind maps navigation to see if navigation would aggravate the bad behavior. well it didn't. perfect results! this is both reassuring and disapointing. while i can be a little more confident in my gps which in the past has been good except when using google navigation it also make me wonder if maybe the gps is just plain unstable and cant be predicted.

did samsung get it right in the base rom that eugene worked from? did using control plane fix it? did i just get lucky today with different results tomorrow? does touchwiz somehow cause the problems(not likely but who knows)? eugene did a pretty good job of removing touchwiz from samsung sources, not true aosp but it would fool most.

did i stumble on a unique combination thus fixing my gps? im sure the answer is no. it is either in the control plane settings with da_g's mods or in the rom itself.

the jl3 modem seems to get a slightly better signal but is certainly not a "fix"

will you have similar results? dont know, try it. but be warned that the rom is giving me some funny battery reporting and the standard recalibration isnt really working. i also had some random shutdowns when i used juice defender(maybe a bad install on the app) it also is not likely to work with samsung widgets and the video player wont play those weird media hub files.

i do believe that axura was built off the same base rom (im really not sure about this, just a hunch) but i had no luck with gps on that rom, i didnt use axura long enough to try fixing it but others report it as being very good.

i wonder if anyone has looked into available ram as a cause? eugenes rom seems to have a small memory footprint and i often have over 200mb free! could minfree be killing a service when ram runs low? could a setting in other roms be killing a service when exiting some gps apps for the sake of ram/battery usage?

im not a dev and would have no idea where to start on this. i also know that much files that control gps are proprietary and cant be fixed by the community, we can only hope to identify the problem and employ a workaround to prevent problematic situations assuming that the proprietary files are infact more or less functional. will samsung employ a fix? well i think with the number of identified problems with the gps that the galaxy s was released prematurely. samsung likely rushed the release to get a bunch of ooohs and ahhhhs without doing enough testing. it appears that they are incrementally improving gps performance over several builds and it may continue to get better, maybe over several updates. untill then ill use eugenes rom. i also think that if froyo builds did not help you then you may have an antenna issue!

ill attach the my tracks file when i have time.

i would like to thank clshortfuse and especially Da_G for there efforts. Da_G i hope you find a solution that we can all use regardless of rom, or maybe you can cook up a rom yourself, people would definately use it..