Friday, March 28, 2008

LocateMe - Free J2ME GPS Tracking Software

UPDATE: LocateMe 1.1 is now available which you can get here

--- Original Post follows ---

LocateMe - Free Open Source GPS Tracking software for MIDP 2.0 mobile phones.

This simple application requires a Bluetooth GPS and will show you the direction to a given GPS location (a "target") without maps, using a pulsing direction arrow. You can request the location of other LocateMe users by text message, send your own location, or just simply save a location for directions back to it later.

The features:

  • "Target" other LocateMe users' locations via a request text message

  • Send your location to other LocateMe users via text message (can use your contacts list)

  • Record your last location as a target

  • View all the satellites around you on a "radar" style view

  • Display RAW GPS data (suitable for testing)

  • Connects to any bluetooth GPS

  • Saves your bluetooth GPS and last set target settings

For developers the fully commented source code is a good example of:

  • Design patterns, i.e. lazy initialization, command, strategy patterns

  • 2 Tier system

  • How to use PushRegistry (JSR 118)

  • How to use the Record Store (JSR 118)

  • How to use Bluetooth (JSR 82)

  • How to use Text Messaging (JSR 120)

  • How to use the PIM (and hack to minimise the security notices - JSR 75)

  • How to use the Location Based API (JSR 179 - Nokia lapi.jar included)

  • How to use simple graphics (not using a Game Canvas however)

  • How to multi thread effectively

  • Provide a basic understanding into Graphical and GPS trigonometry

Known Issues:

  • The application is not security signed (this costs money!), so you will be shown numerous security popups.

  • As your phone is not a compass the direction target arrow will only point to the correct direction once you start walking, and the phone can determine which way relative to North you are going, i.e. when you are stood still your phone doesn't know which direction you are facing! :)

  • On first run there can be some delay discovering the bluetooth devices in busy areas (i.e. it may display "Waiting for GPS..." on first run for some time). This is down to the bluetooth device discovery picking up a large number of devices and querying them. Once you have located your GPS, future connections to the GPS do not require this discovery period and will be relatively quick

This software has been tested on Nokia Series 40 3rd edition phones at a minimum resolution of 128x128 pixels and Sun WTK emulator at 240x320

The software is licenced under the CPL 1.0 licence which is included with the distributions.

Download LocateMe 1.0 JAD and JAR for Java phones
Download LocateMe 1.0 source code
Download LocateMe 1.0.1 Beta source code (with basic integrated GPS support) See this page for more info on the beta.


Anonymous said...

Thanks for giving this away. I've been looking for something like this to teach me Java Mobile

Anonymous said...


I've written some code to use the inbuilt GPS on a Nokia N95.

I can't find any method of contacting you at all, so if you're interested in it to include in yours, please email gmail@com.caluml - turning a@b.c into c@a.b.

Anonymous said...

i really enjoy your programm. i am using it on a Sony ericsson m600i.
when i use your finished jar/jad it works perfectly.
but when i compile it on my own and try to install it on the phone, i get an autorisation error.

is this due to the fact that you reference the location api?

how did you get this to work though?

since i would really like to experiment a bit with your code
please contact me via email: stefan DOT lembach AT gmail DOT com

Anonymous said...

I managed to download the Jar / Jad files and got them to work fine, but couldn't download the source code - ie the link went off elsewhere? Would be good to do so. Many thanks, J

Unknown said...

Hi, the project is fantastic, i've tryed the software on my sonyericsson k800i and it worked great!
But is really fantastics if the program can record the position to export for openstreetmap. (Store a file and sent it to the pc)
I'm italian, but if i can help for translate or to test...

Unknown said...

I'm trying to write the code necessary to store a file.gpx for the openstreetmap project, (an xml file with the coordinates aquired).
But i'm not a programmer i need help for comment or rewiew. Can you contact me?
If you have time please...

We can implement a software for example "TrackMe"

Anonymous said...

I have a desperate need for such a function on my Nokia 6650 with integrated GPS.

As I'm not a programmer, I'd need the executable JAR of LocateMe 1.0.1. Can anybody *PLEASE* send me a copy?

please send to


Thank you!


romsjain said...

I tried your application, it is working .
when I compile your code it is working on J2me toolkit environment, but it is not working on mobile.
It is showing "Invalid application".
Please Help me.
I need this code in my project.
Please Help me.
If you can send me source code on my account then please send it on
Otherwise please please reply.
I need now only your help.

romsjain said...

thanks for your powerful application,
it is working on my mobile perfectly.
I downloaded your source code of LocateMe 1.0 and 1.1

When i compiles and runs it on j2me toolkit environment it is woking , but when i try it on mobile after creating .jar file it not working.
It shows "Invalid Application".
Please Help me.
I need this source code in my project.
Now only you can help me.
Please send me source code if there is slight change.
Once again thanks,
your friend.

Roms Jain said...

Thanks for your application.
I tried it, it is running perfectly on my mobile.
I also tried the code given by you.
It is running perfectly on J2ME toolkit environment.
When I tried this on my mobile,
it is showing "Invalid Application".
I need this code for a project,
Please Help Me.