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

globalsat tr102 personal GSM GPS locatorA palm sized device with built in global positioning (GPS) and mobile phone connectivity (quad band GSM). Put it in a pocket and you can be located anywhere in the world where there is mobile phone coverage.
The tracking can be done either by SMS messages or with a continuous flow of of positions in GPRS mode.
In SMS mode you can either send an SMS or call the device and it will send back an SMS with the current position. This mode is the easiest one to set up and to use.
SMS is universally supported by all mobile operators whereas GPRS isn’t.
In GPRS mode the device sends the current position at predetermined intervals (for example every 60 seconds) to a server.
GPRS mode is great for when you need continuous updates like in a sailboat race or during logistics tracking.
This mode can also be the safest option in personal tracking as in the case of a lost GPS signal, you can view the latest acquired positions.
GPRS mode requires a PC running the supplied “Call Center” software or a server with custom software to collect and publish the data.
Incidentally I have developed such custom software to collect TR-102 data from multiple devices and a Google Maps front-end to view it. This allows me to use GPRS mode without maintaining a PC and to monitor a device from any browser in the world (more details about this later).
The GPS unit in the TR-102 consists of a SirfIII chip which is a top of the line GPS chip. It is highly sensitive to allow tracking even inside a building.
The GSM module is quad band (850/900/1800/1900 MHz) which means truly global support. Still you should look into the GSM and GPRS support of an obscure country before traveling there.
Globalsat TR-102 can also serve as a rudimentary phone because it can receive calls and make calls to up to 3 predefined phone numbers.
Finally the TR-102 personal locator unit also features an SOS button. If pressed, the unit sends an SOS SMS message with the current location to 3 predefined numbers.
Charging is done with 5V and a 4mm plug with same dimensions as for a Sony PSP. This means you can use a PSP USB synch and charge cable for charging the unit on the go.
All in all the unit is a fantastic piece of technology but it has some issues. Hopefully some of the issues can be addressed in the next version of the device.
1. Non-standard mini USB connector. If you misplace the original USB cable that came with the unit you have to get a replacement from Globalsat as standard mini USB cables will not fit. Update: the connector appears to be a 4-pin mini USB. It does not appear to have a specific name but has a single grove that allows it to be identified.
2. The TR-102 does not support commands OTA (over the air). It would be useful being able to send an SMS to instruct the unit to switch from GPRS mode to SMS mode.
You have to connect the unit to a PC to be able to do any kind of set-up.
I would suspect such functionality can be supplied in the future with an updated firmware.
3. Not yet a truly transparent solution due to the size of unit and GPS signal loss issues. Transparent personal GPS tracking will only be possible when devices can be worn as a wristwatch or be integrated into personal clothing.
Dimensions: 115 mm, 45 mm, 22.5 mm, 100g
Update 14 May 2007
In a twist of faith the unit was stolen last weekend. The unit was switched off or else I would have been able to locate it and together with it the thief.
This incident points out additional weakness of current personal locator devices: if the unit is switched off or batteries are dead or if it is discarded or destroyed by the perpetrators it is rendered useless.

5 thoughts on “Globalsat TR-102: personal GPS/GSM tracker and locator”

  1. 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.

  2. 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,

    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.

  3. 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.

  4. 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.

  5. 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,

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