GPS Car Tracker - Cheap and Covert

I set myself a challenge this week! Build a covert Diy GPS Vehicle Tracker for less than $20!

Obviously I could buy and install a wired tracker (or battery tracker) but they are pretty expensive and where is the fun in that? I want to see if I can put together a covert Diy GPS Tracker from bits I can plug together from Ebay......and no, there's no coding!

There have been a number of robberies in my area in the last few weeks. You know how it goes... thief breaks in through the backdoor, steals the keys from the kitchen drawer and you don't have a car any more. It's common practice for the thieves to park up the car for at least 24hrs after the theft in case the vehicle is being tracked. If it is tracked then you are likely to get your car back.

We are a two car family without fixed trackers - I generally track my vehicle using the Pay as you Track App on my Smartphone. This works really, really well but my Smartphone is not going to be in the car when the car is stolen.

How do I keep a charged Smartphone in the car so it can't be found?

You'll need a 12v to 5v (micro usb) voltage dropper like the one the picture. You can get lots of different types but I selected one with simple red/black 12v in and a micro usb out.

I picked one of these up from Ebay for <$5

This is a Samsung Galaxy Y. When it first came out this phone retailed for around $100. If you've ever used one you'll know they are pretty slow. You can just about use them for making calls and for sending SMSs.

Not much fun trying to browse the web. One thing they do have going for them is a (not great) GPS chip and a data connection. You can now pick one up from Ebay for less than $20.....so I started thinking. All I need is a power source, some android software and a box and I'm pretty much there.

If you want live data then you need a SIM with data credit on it. This is optional because you could set up the wifi on the phone and only download your tracking data when the vehicle gets a wifi connection.

I wanted my tracking to be live so I found a cheap SIM. If you google M2M SIMs you can find some companies that do really cheap data sims with a small data allowance per month. You need less than 10Mb.

I found an App that does vehicle tracking using a mobile.

Head over to http://payasyoutrack.com and create yourself an account. This takes approximately 1 minute and just requires an email address. Make sure you click the link in the validation email and keep a note of your account name.

After you've created an account open Google Play on your phone and search for payasyoutrack. Install the app.

There isn't much to fiddle with in the App. The first time you start it, it will ask you for your account name and a vehicle name/registration.

After this, make sure that the phone GPS is turned on. You also might want to change the default tracking hours in the App to track all day rather than the default of 07.00am to 11pm.

That's pretty much it for the phone. You might want to take a trip in your car and check it is tracking. You can see your tracks by signing into your Pay as you Track account here.

Locate a constant 12v supply in your vehicle. You need a constant supply as the phone will go flat in about 24 hours if it isn't being charged.

I've got a Volvo XC90. I had to do a bit of research but finally found one connected to the 12v cigarette lighter socket in the cargo bay. Once I'd found it getting to it was actually very easy. These guys helped me out a lot!

I unplugged the feed to the 12v socket and tapped into the wires using a couple of T-Tap connectors. I've never used these before and I found them a little fiddly, they needed properly crimping with a pair of pliers rather than just pressing together. If I do it again I would use a different type.

Put it all back together! I actually put the phone and 12v -> 5v usb power in a box and dropped them into the space under the trim. Don't forget to plug the socket back into your cigarette lighter!

This is the part when I can relax a little, when I set out on this project I had a number of major worries.

• Would my cheap Car Tracker get a GPS lock hidden in my car?
• Would the GPS quality be good enough?
• Would I be able to find a constant 12v supply?
• Would I drain my battery?

Worry #1: Would my cheap phone get GPS lock hidden in my car?

It actually works really well. The Pay as you Track App is pretty clever. It has some neat features which mean that once you've installed the App and registered your phone you don't need to go back to it.

Firstly, the App auto restarts when the phone reboots. This means that even if your phone restarts or runs out of power as soon as it starts up again the Pay as you Track App will fire up and you'll be up and tracking again.

Secondly, it automatically detects when the vehicle moves, this means you don't have to tell it to start tracking it just does it.

Lastly, if you go out of SIM coverage the App will buffer all your positions and send them on when it next has a data connection. If you happen to not really want live data then you don't need to even put a Sim in the phone. Just set up the wireless access details and the phone will download it's positions next time it gets a wifi connection.

Worry #2: Would the GPS quality be good enough?

Ok, lets be honest, the GPS in cheaper phones can be pretty poor. However, I was actually pleasantly surprised, GPS tracking was pretty excellent. The Pay as you Track App records a position every 30 seconds unless you turn. So if you driving around a town you actually get a lot more positions logged than once every 30 seconds. Here's an image showing part of my journey at the weekend.

Worry #3: Would I be able to find a constant 12v supply?

This was definitely the hardest bit of the whole project. Locating a suitable source required some research on the internet and a bit of trial an error. However, once I had located a source fitting the tracker was pretty easy.

Worry #4: Will I drain my battery?

I need to be realistic about this. I drive a large diesel Volvo XC90 with an enormous battery. I also use my car almost every day for more than just running around the town. So in my case, I don't think I'm going to have a problem.

There is a big difference between my phone tracker and a wired or plug-in tracker. My tracker draws power from the battery all the time, a purpose built tracking device will have an ultra low power mode and draw a lot less current when the vehicle is not moving.

I hooked up my multimeter to my diy car tracker to see what the current draw was. The phone was fully charged at this point as it had been in my vehicle for a few days.

Current (mA, screen off, gps on, wifi off) ~ 80mA.

My XC90 battery is 80Ah so if there were no other drain that would be 41 days.

The tracker has been in my vehicle now for a month. Hasn't missed a journey and all is tickerty boo!