Why Does GPS work fine one day and not the next?

[boe]

Hello,

I've read many posts about how they do the firmware update, the GPS works great the first day and not the next. I don't think I noticed a solution or conclusion as to why this is. I've done about 4 firmware updates myself and found that to be true as well.

I'm guessing Sprint either downloads something to your phone that disables it or they somehow track your GPS usuage - those are justs guesses of course.

Anyone have any insight as to why it will work for me one day and not the next even though I test from the same general area - 4 bars of signal, EVDO access.


Thanks

FYI - I did another firmware update this weekend - first time I could use GPS without priming it with GPS viewer - using 3.02 chef downloaded on Saturday like 5/24 - not at my home PC right now. Radio 3.35.04 PRL 60711
Sometimes softreset resolves the issue, sometimes not.

[ScrapMaker]

FYI, GPS on the Vogue is mostly NOT A-GPS... In fact, I can't say I've ever seen A-GPS ever work... It works (for free,) off of the US Military's GPS satellites.

Sprint cannot block true GPS, and I don't believe they try to block A-GPS either...

The reason the GPS works one day, and not the next, has to do with stand-by mode. I have noticed, if I use a program that utilizes GPS many times a day, like GPSToday, then I lose GPS ability after a few hours. It has to do with the GPS driver and standby... If I disable the automatic feature of GPSToday, then, I can use GPS almost indefinitely without a problem. I determined that 99% of the time, GPSToday doesn't really provide useful information on the Today screen, but the geotagging software is fairly useful. I turned off the automatic update on GPSToday, and turned on geotagging. When I take a picture, THEN it connects to the GPS. If I wait for GPS to connect, tag the picture, and wait for the GPS to disconnect before turning off my phone, I have no problems.

Before, with automatic update, GPS would turn on simply from getting a text message. Many times, my phone would turn itself off before it got a lock, causing the GPS driver to eventually freak out... Heck, maybe it kills the driver if it encounters too many unsuccessful lock? Who knows... but it sure isn't Sprint...

[yeaidid]

Originally Posted by boe

Hello,

I've read many posts about how they do the firmware update, the GPS works great the first day and not the next. I don't think I noticed a solution or conclusion as to why this is. I've done about 4 firmware updates myself and found that to be true as well.

I'm guessing Sprint either downloads something to your phone that disables it or they somehow track your GPS usuage - those are justs guesses of course.

Anyone have any insight as to why it will work for me one day and not the next even though I test from the same general area - 4 bars of signal, EVDO access.


Thanks

FYI - I did another firmware update this weekend - first time I could use GPS without priming it with GPS viewer - using 3.02 chef downloaded on Saturday like 5/24 - not at my home PC right now. Radio 3.35.04 PRL 60711

I thought mine was broke too, go here: http://forum.ppcgeeks.com/showthread.php?t=26410

I can't tell you how much this helped my GPS issue!

[ScrapMaker]

Originally Posted by yeaidid

I thought mine was broke too, go here: http://forum.ppcgeeks.com/showthread.php?t=26410

I can't tell you how much this helped my GPS issue!

I'm guessing he already did this... so did I, and I still have the issues..

When it WORKS, it works great... usually less than 10 seconds for a lock... but when it stops, it's dead... soft-reset is the only way...

I wish there was a way to truly STOP the GPS driver when you weren't using the chip... save battery... then start the driver when you needed it...

[shadow-tech]

i have promised to try this but havent got to it yet. a few said it it works

Originally Posted by JOLLYROGER

And now some final notes about slow satellite tracking (GPS 101 if you will...):
All GPS units store information about the GPS satellite constellation. These are not geo-synchronous satellites like DirecTV or Sirius Radio. They are in lower orbit and are constantly moving.

Once locked on, the GPS satellites move in and out of visibility, the GPS stores a running log of when and where it last saw a particular satellite allowing it to more accurately predict when it will see that same satellite again and approximately where that satellite will be in orbit at that time. The more accurately a GPS can predict a satellites location, the quicker it will lock on to it.

Since the entire constellation cycles every few hours, I left my phone sitting docked on the cradle over-night running Google Maps in GPS mode in order to let the GPS unit build up a good solid almanac of the constellation. This morning I'm consistantly able to track 7-9 satellites at any given moment and it only takes seconds to lock on after exiting the program. This includes hard resets, soft resets, standby mode, etc.

All that said, the longer you let your GPS run, the better it will get. Conversely, since the satellites do shift orbit somewhat, the longer you let your GPS sit between uses, the more out of date your almanac becomes, and the longer it will take for that initial lock on.

[ScrapMaker]

Originally Posted by shadow-tech

i have promised to try this but havent got to it yet. a few said it it works

I wonder if that is coincedence? I don't know where our Vogues would even store that info...

It's questionable if QuickGPS even does anything, and it downloads the current/planned positions right to the phone, no pattern-learning necessary... and it doesn't do anything, so far as I can tell...

[samnyc]

Originally Posted by ScrapMaker

I'm guessing he already did this... so did I, and I still have the issues..

When it WORKS, it works great... usually less than 10 seconds for a lock... but when it stops, it's dead... soft-reset is the only way...

I wish there was a way to truly STOP the GPS driver when you weren't using the chip... save battery... then start the driver when you needed it...

I haven't had this issue yet since I never leave things running that use the GPS. Do you have to reinstall the PPST sprint CAB, then run PPST.exe again or does a soft reset always bring the GPS back?

[gedster314]

Intresting, about the gps database. Maybe that's why mine does so well. There have been a few nights where I just left gpstoday run all night while plugged in. I'm not a fan of gpstoday but I use it to kickstart the gps before I go into igo6. Ig06 just does not seem any good at starting the gps. I've installed the geotagging option but have not used it yet.

Today I got 11/12 satellites, I don't think I've ever seen that on my vogue before, most of the time it's 7/8.

[yeaidid]

Originally Posted by ScrapMaker

I'm guessing he already did this... so did I, and I still have the issues..

When it WORKS, it works great... usually less than 10 seconds for a lock... but when it stops, it's dead... soft-reset is the only way...

I wish there was a way to truly STOP the GPS driver when you weren't using the chip... save battery... then start the driver when you needed it...

Have you tried turning off the gps in the application you are running, IE after I finish with Google Maps, I uncheck "use gps" before closing it, after that i can open any application and use gps without fail.

[vaxick]

I'm hoping we might see a difference when a official ROM comes out with GPS.