GPS Anti-theft device - A Nerd's Approach

[rasjad]

We bought our AS a few months ago. Given it wasn’t a cheap investment and I’m a bit of a technology nerd I started investigating a way to “track” my AS if it was ever stolen. There are systems out there to do this but they tend to be pretty pricey (eg; LoJack). I wanted something I could “hide” in my trailer and it would let me know if something was going on – all for as little $s as I could get away with.

Well here’s my solution:

Be warned – this is not for the technical/electronic/computer phobic. If you want to try it, having some tech/computer background would be good. But I’ll try to give as much detail as I can.

1) Geogram ONE:
I purchased the Arduino based Geogram ONE – from DSSCircuits.

See “Geogram ONE.jpg” below

I also purchased from DSSCircuits:
Lithium Ion Polymer Battery (1500mAh)
Quad Band Cellular Antenna
U.fl to SMA Adapter Cable
FTDI Cable (3.3v IO)
Total cost $161.50

Here’s their website:
Geogram ONE

DSSCircuits has a “forum” where you can get advice and post questions (which I did a lot of). Also there’s great advice there as well. Some of the things added/changed were based upon other people’s experience on the Forum.

2) SIM Card:
You will need a SIM card to use the Geogram ONE. So I purchased one at H2O Wireless using their “Pay-as-you-go” option for $10. The $10 should be good for 200 text messages, but does need to be “renewed” every 3 months. So I figure it will cost me $40/year to “monitor” my AS. That seems like a reasonable cost.

You have to get a “Starter Kit” for $9.99 and Shipping for $10.00 – so initial cost is $29.99. It took about a week to get the SIM card.

See “H2O SIM Card.jpg” below

Note you have to “activate” the SIM card once you get it!

Here’s H2O Wireless website. Note they use AT&T as their wireless carrier.
https://www.h2owirelessnow.com/mainC...p?page=planMin


3) Getting the Geogram ONE working:
The DSSCircuits site has pretty good installation instructions. However, a few hiccups I ran into:
- The SIM card holder “folds back” – it’s not obvious from the instructions.
See “Sim Card Holder.jpg” below

- Snapping on the u.fl connection is a bit tricky.
See “u.fl connector.jpg” below

- Note that the connector for the Lithium battery is keyed.
See “JST Lithium Battery conector.jpg” below

Once I got everything put together, I tested the unit and it seemed to work fine. On an amusing note, I took it with me in my car and it kept sending me messages that I was speeding ;-)

One note of caution – I sent it a command to “sleep” and apparently did it wrong. It went “dead” and the only way I could fix it was to download and re-install the software. I won’t use the sleep command again!

4) Useful Geogram ONE commands:
After some of the difficulties I had with sending the sleep command – I’ve limited my “commands” to a basic few;

Option 0 – Geogram ONE will text your cell phone it’s current GPS coordinates. Assuming you have a smart phone, selecting the coordinates will take you straight to a display of the location on Google Maps.

See “Google maps example.jpg” below

Option 1 – Motion detection.
This option sets the Geogram ONE to notify you if motion is detected. This mode apparently draws very little power so is a great way to “arm” the unit to let you know if someone has moved the trailer.

It’s not very sensitive. I put the unit in my car and drove away. About a mile from home I ran over a manhole cover, which set off the unit. Although I’d like it to be a bit more sensitive – on the other hand I don’t want it to be set off by strong winds. So I think it will be OK. Net time I take the trailer on the road I’ll see how quickly it notifies me of movement.

Option 2 – Geofence.
You can set a “Geofence”. This means that if the unit moves out of a user defined circle, the unit will notify you. Typically a Geofence is at least 100 feet in diameter. This mode draws more power than the Motion detection mode so I won’t be using it. I suspect that if you plug the unit into your trailer batteries (see below), the draw is not significant – but I haven’t done the calculations.

Option 4 – Send coordinates every XXX seconds.
IF the trailer were to get stolen, you can send this command and it will continuously send you it’s GPS coordinates. I’d probably set this to 5 mins to start with. Remember that if you bought the $10 H2O Pay-as-you-go option, you only have 200 text messages – so that last thing you want to do is to run out of messages before the police find your trailer!

Option 6 – EEPROM configuration settings.
There are several things you will need to tell the Geogram ONE. At a minimum, you need to enter text messages that you want it to send you if motion is detected, and the message for if the Geofence is breached. If you don’t define any text for these – nothing is sent (the first time I tried the “Motion detection” option I thought it was broken, until I realized I hadn’t defined the text message to send me)

5) Eliminating the Lithium battery:
Once I knew it worked I wanted to set it up so it was always plugged in and not dependent on a lithium battery. I wanted to do this for 2 reasons; a) I don’t trust Lithium batteries – although very uncommon they have been know to catch fire. I didn’t want to take the very small chance that I would “burn up” my AS!, And b) it would be very inconvenient to have to regularly use a USB cord to “re-charge” the battery.

On the Geogram ONE forum site, someone posted a way to eliminate the lithium battery. Here’s the thread – see the 5th posting down by Neptune:

12v car battery power source and low voltage disconnect

This small voltage supply cost me $10.80 from oddwires.

Neptune goes on to say that he replaced the potentiometer with a fixed resistor. I think it’s unlikely that this is necessary, but I did it any way. PLEASE NOTE – if you want to do this, the unit I got from oddwires was slightly different then the one Neptune had – I used a different size resistor (see photo below). If you want to do this you should do some careful testing – that last thing you want to do is fry your Geogram ONE!

See “Modified power supply.jpg” below

6) Final Setup:
Here’s the final setup ready to be installed. I’ll add an in-line fuse, wire it directly to my batteries (before the On/Off Power switch) and “hide it” in a non-obvious place. I’ll post more information once I have it installed and try it on the road.

See “Completed unit.jpg” and “Unit in case.jpg” below

My total cost was a little over $200 and will require about $40/year to maintain. This seems like a reasonable cost for some “insurance”.

For those brave souls that may want to try this – good luck. I make NO claims that this will work for you.

Some sources of electronic “stuff”:

Adafruit.com
(JST connector - JST 2-pin cable ID: 261 - $0.75 : Adafruit Industries, Unique & fun DIY electronics and kits )
(DC Power cords/connectors - 2.1mm DC Barrel Plug to Alligator Clips ID: 1329 - $1.95 : Adafruit Industries, Unique & fun DIY electronics and kits )

Sparkfun.com

Makershed.com

Then the old standby – Radio Shack (both local store and on-line)

Rasjad

PS – my next “nerd project” is to create a GPS tracker so I can automatically download all of our trips onto Google Maps. Although I suspect the the Geogram ONE could do this, it would require me to modify the Arduino C+ code – something I really don’t want to tackle…

[Shacksman]

I found it was much simpler to buy a second trailer. If one goes missing I can use the other.

[RickDavis]

You just call the insurance company and say "remember that trailer I used to have?"

[Arcticfox]

I'm with Rick on this....lol
But I must say the parts of this post I actually understood - it sounds GREAT!

[Wolfe]

I got a SPOT TRACE THEFT ALERT & TRACKER DEVICE AT West Marine for $99.99 and 100.00 a year.
It uses Sat's so cell's arn't needed. Inside the A.C. cover is ideal clear shot to the birds. Add a small solar panel,charge controler and gell cell bat. if they bring a lader to git on the roof, (i think not.) it could be defeated.
A small price to protect a hi $$$ trailer Don't you think.

[Ag&Au]

Rasjad,


First of all, I complement you on your inventiveness and perseverance. I appreciate the time it took for you to make this device and document it for the rest of us. I can tell you enjoyed doing it also.


I doubt that even with the excellent guidance you provided that I will reproduce it. However, I will read it carefully and see what I can learn from it.


Ken


P.S. If you had an amateur radio license you could interface a GPS with a ham transmitter and periodically have it broadcast your position. This data would be saved to the internet. you could latter retrieved this data. If interfaced correctly, it could turn on if your trailer was stolen.


Search the internet for APRS.

[masseyfarm]

If you have a BlackBerry, or probably any other smart phone, you can, with one touch, send an email of any location you are at.
Most car cams also will record your GPS locations.

Dave

[Siegmann]

Buy the cheapest smartphone you can find. Load a cheap or free location tracking app on it. Put the phone in a cabinet with a 12v outlet and connect to 12v charger. If you're not plugged in, and are gone for long periods (in storage?) you could add a solar battery tender.

[65CV]

Rasjad,

Thanks for taking the time to document the project so well. The Ardunino tools look like fun -- I plan to try a project or two when I get the chance.

You may also be interested in another well-documented Ardunino project -- Zep's Tank and Battery Monitor.

John

[RickDavis]

Originally Posted by Ag&Au

Rasjad,




P.S. If you had an amateur radio license you could interface a GPS with a ham transmitter and periodically have it broadcast your position. This data would be saved to the internet. you could latter retrieved this data. If interfaced correctly, it could turn on if your trailer was stolen.


Search the internet for APRS.

Here is an example, although this is in my truck

K8DOC-14 Location

Doesn't work everywhere, but I can still retrieve info on where I was years ago

[RhinoWW]

Love the post. Learned a ton, which is one of the reasons I like this forum so much and read lots of threads as I continually get beat by a few minutes to buy the barn fresh AS of my dreams.


I am, however, with those who say that this is where insurance comes into play. Many insurers will allow you to have an "agreed value", as you are basically paying a percentage of that as your premium. If there is a total loss, you know what you are getting. Worked well for me when my wife's ten year old minivan was totaled when she was rear ended.


Now the tracking component has all sorts of other features say if you have teenage kids who don't like to answer their phones . . . but there are apps for their phones that will do that as well.

[hhendrix]

Fascinating. Nice work

[Skatiero]

Fascinating! What a clever solution, thanks for posting.

[rasjad]

Ken's correct - I did this because it was fun. I retired 3 weeks ago and had nothing else to do.

And yes I have insurance. But I like what Doug said - get a second trailer!

I'll look into the CB option - hadn't even thought of that! Also I like the idea of a tank monitor.

Rasjad

[JimAspinwall]

To be technically correct. The satellite aspect is only receiving from the GPS sats. No consumer devices send TO the satellites. The device data is sent via old-world 2G GPRS packets - relatively unused cellular function now that everything else is 3G/4G. A LOT of tracking and pay-as-you go insurance and driver mileage schemes use the same thing.

p.s. - the amateur radio APRS solution is 'free' for the 'service', one time cost of getting the license and about $200 worth of gear/antenna to setup. Once you have the license it's also a great way to have more on-road communications for local help.

p.p.s. - to another note, it is not legal or practical to try to send data over AM or SSB CB.