Database Users

Developing a GPS application - some questions

Hi
I'm developing a GPS application to assist devices with onboard GPS chips (eg. Trinity) to obtain a fix faster.
My application works fine thus far, however I have a question in regards to TomTom. Every other application works instantly, ie. they report the fix obtained as "Valid" and start displaying the location on their GUI almost instantly.. EXCEPT for Tomtom.
Does anyone know what TomTom looks for other than a 2d/3d fix? It detects its receiving information yet hangs on "Lost GPS signal since xxx seconds" for around 2-4 minutes and THEN it starts working fine.
I'm confused as to why this is only happening with TomTom so any information you guys have would be greatly appreciated.

I'm not sure what your application does to assist, or which other applications work fine. But I'll take a guess. Tom-Tom is a stand alone GPS app and the others use assited GPS?
Satellites transmit ephemeris data, data about the orbit of the GPS satellites, every 30 seconds. Tom-tom must lock on to the salelliites and wait a minium of 30 seconds to recieve this data. If the other GPS applications use assisted GPS, they get help from a location based server (LBS) run by the cellular provider. The LBS sends the ephemeris data and other data to help the GPS lock onto the satellites quickly, so the GPS doesn't have to wait.

Wifi and GPS questions

I have a limited AT&T data plan, so I don't want to use my Internet connection through the plan too often. So a few questions.
1. If my wifi is on, does that override my AT&T data connection?
2. I installed Google Maps Mobile. It can find my location without GPS using My Location and cell towers. How can I turn my GPS off, so it doesn't transfer data?
Thanks.

Note that the GPS itself does not use the data connection, so it doesn't matter if Google Maps uses it or not. Google Maps is using the network (either WiFi or data) connection to get the map data, and would need it even if it doesn't use GPS for position.
If you were to buy 3rd party navigation software such as TomTom, CoPilot Live, etc., all the map data would be resident on your device and you wouldn't need a data connection unless you wanted to get traffic data.

Turn off gprs. Gps is an option in google maps. I do not need or have agps so this is not really an issue for me

Interesting GPS issue...

Has anybody noticed that if you use the gps status app before you use the google maps that the gps connect quicker for any app using gps such as maps, weather, where, etc... until phone reset.
When I run google maps first gps would just search for several minutes and sometimes wouldn't even find the location. So for anyone with gps issue probably try the gps status app from the market first.
I'm wondering if the gps status and google maps access the epic 4g gps differently... just a thought
Sent from my SPH-D700 using XDA App

I did what you suggested and indeed the gps locked much faster on google maps when I used GPS status first.

three epics here. extensive GPS testing over weeks now.
what you are seeing is gps status forcing aGPS vs "use wireless location, whcih is not aGPS.
If your ephemeris is new or has been cleared (the Epics main problem is not clearing ephemeris) you get an aGPS lock in seconds on GPS/aGPS only application like GPS status. But on application that can use either location method, the non GPS Use wireless networks" or the GPS, it often tries to get a wireless tower location first.
I get the identical affect by turning off the tower based system by keeping "Use wireless networks" normally off. this gives me instant aGPS locks five to ten seconds in proper conditions at all ties with cold start enabled.

[Q] aGPS Server

Hi guys. I live in Brazil and here the GPS takes too long to locate me, so I was wondering maybe the default WP7 aGPS server is not properly "polished" to work here.
Is there any way to change de aGPS server via MFG App and/or Registry Editor?
Thanks

Optimus 7 uses a dedicated GPS chip. Real GPS, in conjunction with WiFi location and cell tower triangulation. It does not even need a data connection or WiFi to locate your coordinates. And yes, there is a way to choose whether the phone uses 2G or 3G for different purposes while locating you. >Engineer Menu>Device Test>Sensor Test>GPS Test>GPS Setting. Not sure exactly what you are trying to change, but that is the only GPS options available for altering in the MFG app...

gps problem

Hi to all
I have gen1 blade with tpt for gen2. Currently it is with cyanogen-mod 7 ROM. I'm pleased with this phone but it does have one problem. GPS is not working!! To be exact device fails to "see" any satellites. With WIFI I get lock but only because of WIFI and trace of IP address. I heave used modified gps config file but that got my AGPS working, not regular GPS.
I have tried to find service manual on internet and failed....
Any ideas on how to solve this? I did check antenna connections that i could see and all seams to be fine.

No one?
I have tried Swedish snow rom but had same problem. replaced original gps.conf file;e with modified one and still had problem.

I guess u have not switched on the location services.
Go to settings location services then tick mark all and in GPS source select internal
Sent from my Blade using xda premium

udaytalwaronline said:
I guess u have not switched on the location services.
Go to settings location services then tick mark all and in GPS source select internal
Sent from my Blade using xda premium
Click to expand...
Click to collapse
AGPS works. I do get position according to WiFi but as i leave WiFi covered area I don't get tracking. No updated GPS position, according to software there is no visible satellites.
I have given up on getting this fixed. I have tried different ROMS and programs. Only when i get location from WiFi using ether Google maps or Locus I have position. Using GPS Test app i never get position. Same goes for other apps. I do have old (5 years old) BT GPS dongle and he finds position and satellites within 1minute using this mobile.
I have tried to find service manual or some sort of technical info about GPS in this mobile but found nothing.

grunf said:
AGPS works. I do get position according to WiFi but as i leave WiFi covered area I don't get tracking. No updated GPS position, according to software there is no visible satellites.
I have given up on getting this fixed. I have tried different ROMS and programs. Only when i get location from WiFi using ether Google maps or Locus I have position. Using GPS Test app i never get position. Same goes for other apps. I do have old (5 years old) BT GPS dongle and he finds position and satellites within 1minute using this mobile.
I have tried to find service manual or some sort of technical info about GPS in this mobile but found nothing.
Click to expand...
Click to collapse
Do you have any screenshots from GPS Test app at least?