GPS tracker

Published 16th January 2021
Updated 9th February 2021

I wanted to add remote paging to my alarm system and I came across a TK103B GPS/SMS/GPRS tracking system. I’m quite impressed with the possibilities of this device. It can call or text your mobile when triggered but it can do much more. This is what I did:

Remote paging

TK103B GPS/SMS/GPRS tracking system

TK103B GPS/SMS/GPRS tracking system

Main reason for purchase was to add remote paging to my alarm system. The TK103B could be used a a basic alarm system with door sensing and shock sensor and engine cut-off. It comes with a remote. It can’t operate door locks however so I’ll just use it as an add-on to my soon te be installed Clifford Arrow 3 alarm. I’ll use the door sensing wire to trigger the tracker. The Clifford doesn’t have a dedicated wire to do that, so I’ll tap the wire siren. To avoid triggering the tracker with the alarm on/off chirps, I’ve used a relay with a 5 second delay. The picture shows my setup. The wires on the left go to a power supply (the unit has a backup battery BTW) and the right wire will go the the siren. The wiring diagram shows all possible connections to which I improvised a little.

TK103B GPS:SMS:GPRS tracking system wiring diagram

TK103B GPS:SMS:GPRS tracking system wiring diagram

The GPS-tracker is configured by sending text messages and it will reply also through text messages. First thing is to set up which phone numbers are allowed to operate the device. The main phone number will be used by the tracker in an alarm situation. I’ve set it to call me and I’ve added the phone number as a favorite so it will get through when I’ve set my phone to “do not disturb”.


If you call the GPS tracker, it will reply with a text message with a link to a Google Maps location. You can also configure the device to listen in to the car with the supplied microphone. In that case you can still obtain a location by sending a text message. If you want, you can also use GPRS to track the car with a tracking service. Setting up the Internet connection and connecting it to the service was a chore but it works great. I use GPS-server. When stationary, the tracker will report with quite long intervals but when it registers movement, it will update every 10 seconds so you can track semi-realtime. The GPS-server will keep the track history for 90 days.

The solution is quite inexpensive. The GPS tracker was around € 26 euros shipped. The relay added a few euros’s to that. I used a prepaid T-mobile SIM. There is no need to use GPRS and a tracking service because you can track through text messages. I use a tracking service additionaly. That needed a 1GB Internet bundel (will probably last at least a year) and a GPS-server subscription of € 15 a year. Don’t forget to remove the PIN and enable roaming for use abroad!

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