[Captivate General] shaneaus:
Ok, There are a lot of posts and information regarding the GPS issue that some are experiencing. I am starting (yet) another post in the interest of compiling and maintaining information regarding that information in one location. As users/devs find out information I will update this post so everyone doesn't have to go looking everywhere for the information. I am hoping that the Moderator will sticky this post.

Some users are experiencing very long lock times for their GPS. Everyone, after reading A LOT of posts/threads it seems to be the consensus that this is a software/settings issue - NOT, a hardware issue. However, results from tweaking the following settings are very mixed. Most seem to get great results by tweaking the following settings while stationary - but, moving is a whole different ball game. I use the below settings and have great results while stationary. However, my G1 blows the Captivate completely out of the water!!! My G1 gave 3-10m accuracy while driving. This device can barely keep me on the correct highway and always seem lagging behind my current location. The G1 was spot on no matter what. What hasn't been determined is if these issues are hardware or software. For whatever my opinion is worth - I think it is a firmware/software issue. Here are some things to try.

Here is the info:

To get to your GPS settings open you dialer and dial the following number. This will not call anyone - it is a code shortcut to the settings:

*#*#1472365#*#*

Once entered you will observe a screen that has five buttons:

Get Position Test

Application Settings

SUPL/CP Settings

Test Application

Delete GPS Data

We will be interested in three of these initial buttons

.

Get Position Test: This will be what one uses to test the results of your changes.

Application Settings: Exactly what it says.

SUPL/CP Settings: settings that determine specific data connectivity with the satellites.

In

Application Settings

the following are some that you might consider adjusting:

Operation Mode - Standalone, MS Based, MS assisted, Network Provider

Accuracy - defaults to 50. Don't set it below 10 (and only use increments of 10's)

SkyHook - not sure what it does. But, someone on a thread mentioned it and it DOES effect satellite lock times.

In

SUPL/CP Settings

one we'll be interested in the following:

Server FQDN Type

Server

Server Port

The following are the options provided on other threads:

Original/Stock Settings

:

SUPL/CP Settings/SErver FQDN Type/Custom Config

Application settings/Operation Mode/Standalone

SUPL/CP Settings/Server/www.spirent-lcs.com

SUPL/CP Settings/Port/7275

Second suggested setup

(from other posts and claimed to have great results):

SUPL/CP Settings/SErver FQDN Type/Custom Config

Application settings/Operation Mode/MS Based

SUPL/CP Settings/Server/supl.google.com

SUPL/CP Settings/Port/7276

Other settings that I have played with

:

Application settings/SkyHook/On (and Off)

SUPL/CP Settings/SErver FQDN Type/Auto Config (and Custom Config)

You can play around with these to see what gives you the best results. If your GPS doesn't work better with whatever changes you made - than you can always put it back to the orginal settings above.

However, it has been recommended and I concur (for whatever that is worth) that you NEED TO SET THE FOLLOWING BEFORE YOU START PLAYING AROUND: Settings/Location and security/uncheck (turn off) "Use Wireless Networks). Most likely this won't really effect anything while your testing within the GPS settings - however, this will effect your results if you test using Google Maps, etc.

Now, having duly noted all of the above and having played around with the settings for several hours

I found the best results FOR MY DEVICE IN MY AREA AT ONE LOCATION was the following:

Note: I adjusted these settings from earlier as the earlier settings proved to be very accurate when stationary - but, very inaccurate while moving. The latest settings I'm using are below. Also, look to the bottom of this post regarding changing your gps configuration file. That also helped A LOT. The bottom section of information is from the Official websites that run the time servers(effects GPS performance).

Application Settings/Operation Mode/MS Based

Application Settings/Operation Mode/SkyHook/ON (VERY IMPORTANT)

SUPL/CP Settings/Server FQDN Type/Custom Config

SUPL/CP Settings/Server/supl.google.com

SUPL/CP Settings/Server Port/7276

SUPL/CP Settings/SUPL Secure Socket/Off

Turning "SkyHook" ON assisted in faster locks with ALL of my tested settings when stationary!

My test results with the above would lock on up to three satellites in under four seconds and between 7 and 10 by eight seconds. Google Maps would locate me in about 6-8 seconds.

Using "Get Position Test" the settings in the three lines above consistently gave the not only the fastest locks and the most locks - but, also STRONGER SIGNALS!

I used at least seven different combinations of the above settings and some of them were just as quick - but, not as strong. Most of them were slower.

If anyone has better information to add then please PM me and I will add it to this top post.

LASTLY, I will make some guesses as to what some of the other settings do as I have heard different information:

Application Settings:

Session Type: Tracking or Singleshot - obvious (use Tracking)

Start Mode: Hot or Cold Start - someone posted on a thread that Hot uses data from your last read to get started. Cold start will start all over. So, Cold start SHOULD increase the time for you to get a lock unless you went left the area to an area that had different satellite to look up.

Test Application:

Performance Test: worked for me - but, I found the test above to work faster and give me quicker results for what I wanted.

Hardware Test/Sensitivity Test: Pretty cool - went on forever and I stopped it.

CNO Test: Seemed to test the average satellite signal strength.

Antenna Test: Never worked for me and I received errors.

H/W Test Settings: Settings for the above tests - I didn't mess with them.

NOTE: WANT TO SEE HOW ACCURATE YOUR ACCELEROMETER/COMPASS/ORIENTATION settings are? Check this out:

Test Application/Show Sensor Data - there is no way to calibrate it here... But, you can see just how sensitive your instruments are!!

Delete GPS Data - I didn't select this button and I don't recommend anyone else doing so either unless someone from Samsung tells us what it does. LOL!

FINALLY: Keep in mind that if you are seeing GPS lock times that are in the 3-8 second range (which was what I was getting) this WILL NOT be how long it takes for Google Maps to get the GPS data! Expect 8-15 seconds or a little longer (but, under 30 seconds) for Google Maps to pick up your location. Although the GPS sensors might pick up the satellites - you still have to give the software time to evaluate the data and apply it to the software.

Hope this helps someone out there.

Update/Additional Information (http://androidforums.com/1194187-post197.html):

Hot Start - The GPS receiver remembers its last calculated position and which satellites were in view, the almanac used, and the UTC Time. It then performs a reset and attempts to acquire satellites and calculate a new position based upon the previous information. This is the quickest re-acquisition of a GPS lock.

Cold Start - The GPS receiver dumps all information and resets. It then attempts to locate satellites and then calculate a GPS lock. This takes the longest because there is no known information. The GPS receiver has to attempt to lock a satellite signal from all of the satellites, basically like polling, which takes a lot longer than knowing which satellites to look for. This re-acquisition of a GPS lock takes the longest.

Thanks to Shadow77895 for the link to this info. I altered the settings above. Doesn't effect my results much at all.

MSBased Operation Mode(http://www.vzwdevelopers.com/aims/public/menu/lbs/LBSFAQ.jsp#GenQues11):

What is MS-Based mode of operation?

In MS-Based mode, the network provides the satellite information to the device, based on a rough estimate of where the device is located, and the device acquires the GPS signals from the satellites and calculates its location. After the initial fix, the device operates like an autonomous GPS receiver, until the satellite information must be refreshed, at which time the device goes back to the network to update the satellite information. MS-Based mode is appropriate for applications that require the device location to be updated rapidly, such as a navigation application.

And email thread regarding using the Google settings for GPS(http://osdir.com/ml/android-platform/2009-08/msg00386.html)

NEW INFORMATION!!!

ALSO! Check out this page: http://www.pool.ntp.org/en/use.html:

As pool.ntp.org will assign you timeservers from all over the world, time quality will not be ideal. You get a bit better result if you use the continental zones (For example europe, north-america, oceania or asia.pool.ntp.org), and even better time if you use the country zone (like ch.pool.ntp.org in Switzerland) - for all these zones, you can again use the 0, 1 or 2 prefixes, like 0.ch.pool.ntp.org. Note, however, that the country zone might not exist for your country, or might contain only one or two timeservers. If you know timeservers that are really close to you (measured by network distance, with traceroute or ping), time probably will be even better.

Find your optimal pool server here: http://www.pool.ntp.org/zone/north-america

For US the optimal server is: us.pool.ntp.org

Reference other threads I (http://ip208-100-42-21.static.xda-developers.com/showthread.php?t=731462) I recommend you do the following:

Use Root Explorer or some other method (I use Root Explorer as it has a built in Text Editor and automatically backs up the altered file.) to go to here:

system/etc/gps.conf

Use the text editor to alter the gps.conf file to this (if you are in the US):

NTP_SERVER=us.pool.ntp.org

XTRA_SERVER_1=north-america.pool.ntp.org

XTRA_SERVER_2=http://xtra2.gpsonextra.net/xtra.bin

XTRA_SERVER_3=http://xtra3.gpsonextra.net/xtra.bin

If you are NOT in the US go to here: http://www.pool.ntp.org/en/use.html and look at the links in the center of the page to navigate to the closest pool to your geographical location and use that pool for the top server entry.

REQUEST FOR ADDITIONAL INFORMATION:

Many are suggesting that we do NOT leave the Secure Socket ON. How will this effect data security with our devices? I don't understand how it could hurt us... But, there must be a reason for it. If someone could let me know I would appreciate it.