DIY GPS

December 17, 2007 6:38 PM

Is a DIY lojack plausible?

I recently had my baby stolen. I am understandably paranoid and pissed. My insurance is buying me a new bike, and i plan on protecting it like it's plated in gold. Since i can't afford a dog or a stormtrooper to chain to the bike, i am exploring less obvious methods of theft recovery.

With the abundance of such technology, GPS tracking, cell phone tracking, etc., it seems that it would be relatively easy to cobble together something that would be able to track down a stolen bike. Several people have suggested finding a cheap cell phone compatible with a tracking program to hide in the bike. Is this plausible? how reliable are the different methods...is GPS tracking more stable than cell phone tracking?

I searched for a primer on tracking technologies, but everything seems rather convoluted. I can't really make heads nor tails of the information i'm getting.

Is this kind of what i'm looking for? or this perhaps? (though it seems rather expensive...but can you really put a price on knocking on the door of the guy who stole your bike with a sizable posse?)

help hivemind!

posted by furnace.heart to Technology (12 answers total)

The problem with anything you're going to stick on a bicycle is that even if you can find somewhere to hide it that it won't be removed immediately, it still needs power. Lojack is feasible for a car because a car makes electricity. GPSs can only do a couple days on a set of AA's, and if you're broadcasting also it will be a lot less.

Maybe you could do something like stick a whole bunch of NiMH's in the tube and charge it every night?

That Mologogo thing seems like a reasonable prospect, if you can get the power and hiding issues worked out. How much are you willing to spend? There's a GPRS/GPS module available for true DIY solution that can be smaller and you have control over power, but it will be more 'xpensive than a GPS phone.
posted by aubilenon at 7:02 PM on December 17, 2007

Oh, to answer the question about GPS tracking vs cell phone tracking:

GPS-enabled cellphones do something called Assisted GPS (AGPS). GPS is basically an antenna and a processor; AGPS works by offloading a lot of the processing to a computer at the cell tower. It also can get a fix faster by having a rough notion of where it is (somewhere near the tower).

Usually when people say "cell phone tracking" that's referring to AGPS. You can get a really rough idea of where someone is by what towers the cellphone is visible to but I wouldn't expect that to give you better than neighborhood-level resolution.

Here is an example of a GPS/GPRS module if you wanted to go the DIY way. That gives you more control over power sources and general shape than using a commercial cell-phone. It's also more work and more awesome.
posted by aubilenon at 7:10 PM on December 17, 2007

I'm almost positive I've seen a DIY lojack done with:
Bluetooth GPS unit + Bluetooth enabled phone + phone app to read GPS and send SMSs or emails

The phone app was even written in Java (j2me) I recall. My internetfu is failing me though and I can't find it. But if you're handy with Java you could recreate it.
posted by todbot at 7:25 PM on December 17, 2007

If you want to look into used commercial systems, you should look for truck tracking systems: they're realtime, and (I believe) use cell phone/sim-card technology to send GPS data to you.
posted by suedehead at 7:28 PM on December 17, 2007

I think the main benefit of LoJack is not really that it can GPS-locate your car. OnStar and other services can do that as well. Instead, the main benefit is that LoJack will contact the police for you, tell the police where your car is, the police actually pay attention to what LoJack tells them, and they will go get your car back for you.

Otherwise, you're either stuck going after a possibly armed car-thief by yourself, and/or trying to explain to the police how your car has GPS tracking and why they should come help you.
posted by falconred at 7:44 PM on December 17, 2007

All I'm going to say about Mologogo is that it came in very handy playing Assasins. It gave us pretty good accuracy - we could track people to specific buildings throughout the city.
posted by niles at 8:28 PM on December 17, 2007

Seconding falconred's point, another is that insurance won't give you a disount for DIY lo-jack like they do for the corporate sponsored one.

Really cool idea though...
posted by oblio_one at 8:32 PM on December 17, 2007

Just FWIW, Lojack doesn't actually use GPS at all. It is merely a beacon that can be picked up by a receiver that the police have.
posted by wierdo at 8:37 PM on December 17, 2007

I see it's a Vespa so power is already there, and hiding it is a bit more easy than with a bicycle. I'd join your local ham radio club and rig a radio beacon up to go off if you don't hit the off button every x hours/days. One of the activities hams do is "fox hunting" - tracking the location of a radio source like your beacon. They'd probably have it located within a day or two.

Just be sure that beacon doesn't kill the battery entirely or it'll get noticed too quickly. A lot of hams are capable electronics people and would have fun with this project. The insurance company wouldn't got for it though. It does look like lojack used to support Vespas (4th result) but the text isn't there anymore. It might be worth a phone call to a dealer who supports motorcycles.
posted by jwells at 6:06 AM on December 18, 2007

Response by poster: The biggest problem with lojack is that they want to install the transmitter or whatever on your bike, without you knowing where it is, or how exactly it is hooked up. I do all my own wiring, and work on the bikes, so i'm going to stumble across it. i'd rather have a solution i could fit and maintain myself. *shrugs* just a preference.
posted by furnace.heart at 8:39 AM on December 18, 2007

AGPS is terrible. You wont find your bike in a city.

GPS is doable but youre going to have to hang off power, logic, etc. Ive seen packages for this for cars but its a few hundred dollars. Whats your bike worth? Also GPS doesnt work indoors, so once the thief stores it in his basement it will not give a signal and the battery will drain. Also what happens when you know the bike is somewhere? Are you and 10 of your toughest friends going to commit breakign and entering and assault to get it back? I'd first find out if your local PD can use this information and if they can if they will even bother to act on it. Ive heard many stories of people who say they know where their stuff is the but the police dont care or cant get the proper warrant off 'word of mouth' or 'what my gps told me.'

I imagine good insurance is the best bet here.
posted by damn dirty ape at 8:39 AM on December 18, 2007

The problem is that Lojack is successful not because of what it does but because of the infrastructure and marketing & communication. As falconred says, they do all those things and the cops know what it is.

Say "my car was stolen and it's got lojack" and they know what you mean and have a history with the concept as well as experience.

Say "my scooter was stolen and it's got this tracking system I built myself and we can track it" and you've got a much higher bar to overcome.

If you're willing to deal with this potential issue, you might look at this instructible here. The network s/he is discussing is Boost, so it's pay-as-you-go (far more practical) and the phone under discussion seems capable of running java apps, which someone can presumably write for you to read the NMEA output from a serial GPS unit.

In thinking about it I think I'd go for a solution that used a cellphone that could be set to auto-answer. Connect a device to it that reads the results from a GPS receiver and speaks it into a headphone cable connection. Audio playback chips are crazy cheap and all you need are 0-9 and the word "dot."
posted by phearlez at 1:06 PM on December 18, 2007