Comments on: Globalsat TR-102: personal GPS/GSM tracker and locator

By: Sergiy

Sergiy — Sun, 07 Oct 2007 02:44:47 +0000

Dear David,
TR-102 which I have bought in USA won’t send location SMS when connected there over roaming network with my SIM card issued in Ukraine (Though it does receive phone calls). It works OK with local SIMs. Is this a sort of firmware/localization issue and can it be solved?
Best Regards,
Sergiy.

By: Perry

Perry — Tue, 02 Oct 2007 22:47:24 +0000

Hi David.
Do you know what command I have to send to the TR-102 from my application so that the TR-102 sends it position?
Right now the TR-102 connects to my application but it does not send any data except when I force it with the SOS-button.
My current application is written in Perl and it seems like it all works like it should except that the TR won’t transmit it’s data except when forced.

David says:
Ah, I had the same issue I believe. The problem is that you cannot send anything to the device from your server.
Only the device will initiate a communication with the server when you call it or send SMS to it. It is then up to the server to pass a command.
Have you tested your server with a raw socket connection (like putty)?
When the device connects to a server, it always sends the same long string (the position will be 0,0 if it doesn’t have a fix).
It will then wait for the server to either reply OK or to reply with a command.
If the device receives an OK it disconnects.
If the device receives a command it will send another OK.

By: Serge

Serge — Wed, 01 Aug 2007 10:15:34 +0000

Hi David!
Do you know how to connect it to a car’s power supply to keep it continuously charged?

David says:
A general 12V DC to 5V DC car adapter will suffice.
I noticed that a PSP adapter plug fits in the TR101/TR102 so a basic PSP car adapter should be sufficient!
From the manual: Do not connect TR-102 to AC power adapter during its start-up process, otherwise it can not be turned on properly.

By: Ken Blowing

Ken Blowing — Wed, 18 Jul 2007 17:45:39 +0000

I have been reading your article on the TR-102 personal tracking. I am interested in developing a listener program to sit on our server and allow us to grab the GPS data coming in for multiple devices. Did you find an easy way to achieve this?
Best Regards,
Ken.

David says:
Hey Ken, I chose PHP sockets because that is what I have access to on my shared hosting.
Multiple TR-102 devices can connect to the server and the submitted data is stored in a mySQL DB. Users can then access a web page that pulls the data and shows it on a Google Map.
For a commercial application (where you would charge users for the service and expect a high load) I would recommend a J2ee approach.

By: Sahail

Sahail — Mon, 14 May 2007 13:20:39 +0000

David, nice blog. I am interested to know more about your custom software development.

David says:
Thanks for the interest and earlier help with the TR-102!
I have been doing my mobile device development with j2me on the device and PHP or Java on server side.
I might try out Symbian if the Nokia N82 comes out later this year and is as good as the specs suggest… but at the moment no experience with Symbian.