drhess06259

only way to to a homebrew lojack is to add a gps from a phone and be able to wire it in to keep it on constant. cops can track cell phones with gps.

modifry

Personally I don't like a key/fob combination for 2 reasons -first the keys seem to be big and clunky and I prefer a keychain that's as small as possible. I don't use the "nice" key for my '08 simply because it's bigger. Secondly, too many times in years past I've closed my keys in the trunk, so for a long time I carry the fob separate from my keys. Fewer "OH SH!TS" that way.

The original keyless entry can just be bypassed with a new one - the wiring is simple enough. I think replacing the existing immobilizer will be difficult but you can always move it to a hidden location and leave a key in it, then all you have to mess with is turning the ignition lock with a different key. Or, if you can disable the steering lock go totally keyless. I've thought about that but just don't have the time, too many other projects.

Neutered Sputniks

I found the keyfob fits neatly in the coin pocket in my jeans. Thus, I carry the fob in the coin pocket and the key in my pocket - far less bulky and not that much of a hassle as I empty my pockets into the center console every time I get into the S (6pt harness + cell phone = uncomfortable)

Krenath

I'm definitely in it for the cool factor, but I also want to get to the keyless stage at some point.

If I could have things set up exactly the way I want:
* I'd have a small RFID keyfob rather than a battery-powered one. Sealed and waterproof. I should be able to keep it on me were I to go swimming.
* The doors would unlock as I approach and lock again as I get out of range.
* Steering lock would disengage as I approach, possibly with a solenoid rather than the mechanical lock
* The start button would both start and stop the engine since I would not have an actual key to turn
* A short press on the start button would toggle the 'accessory on' position. A longer press while the engine is not running would start the car.
* Walking away from the car would also toggle accessories off.
* Walking away could also stop the engine.
* A solenoid-powered latch would lock the glove box when I'm away from the car, preventing access to the trunk even if I leave the top down, since I'm not going to be carrying a key for locking the glovebox. Alternatively, the trunk button would simply not work if the RFID keyfob weren't in range.

The major issue is finding an RFID keyfob that can be detected at a range of several feet rather than placed against a sensor, and powering the RFID antenna in the car without running its battery down continuously.

Until then, I guess I wouldn't mind all of the above features with a battery-powered remote

Krenath

That's hardly the only way.

There are plenty of companies that made dedicated devices that wire to the car's power supply report the car's location.

Here are just a small handful:

http://www.brickhousesecurity.com/gps-car-...le-logging.html

s4play

I've done some research on this topic and as an EE I finally determined it's not a good idea from a reliability standpoint.

Anytime you mess with VITAL car systems such as this starter, you'd better be sure it works 100% of the time and have a backup just in case. After looking at the number of things that can fail and not having a backup plan, you'll be SOL and looking pretty dumb standing there waiting for a tow truck....

Electronically it's not hard to bypass the stock system (just look at remote start setups) and then you can use a fingerprint BioMetrics switch, RFID, touch key, entry code, etc..........

However the key fob idea requires a lot of thought - more engineering time/money than most of us have. Case in point, my Lexus IS-F has the remote key fob push button starter. Very cool and convenient but Lexus did their homework and thought of EVERYTHING. For example it is very precise on how close to each door handle you must be for it to operate. While engine is running if you walk away from the car, it begins beeping to remind you if let's say you let your girl drive the car away, once she shuts it off at her destination she will be stranded. The KEY FOB detects if it's in the driver's seat and doors won't lock. If in trunk the trunk won't lock, etc..........plus the Lexus is an automatic. For the s2000 you would also need to consider the clutch safety/bypass, etc.

No way for a single person to engineer all of these sensors in a reliable fashion


rick

Krenath

It would be easy enough to put an RFID sensor on both sides of the car so you can detect if it's in the driver or passenger seat.

How precise you have to be from each door handle is a simple function of where the receivers are located and how powerful the transmitter in the keyfob is. An unpowered RFID tag would, of course, require you to be quite close to the car, but that's a feature, not a bug. You don't want your car remaining unlocked while you're dozens of feet away.

It's easy enough to create a module based on something like an Arduino or Basic Stamp or a little Atmel like Modifry's gadgets that would check for the RFID tag and even beep if the engine's running and the tag is not present.

A little Arduino would have plenty of processing power to handle the job and connect to numerous input to keep track of RFID tags and relays connected to wires that carry voltage when the ignition is on.

Not saying that if we think something up that you'll be required to install it. If you're not comfortable with the idea, feel free to not bother.

I'm sure if Modifry had bothered to post half his ideas before he actually made them, he too would have had people telling him how it was impossible and a bad idea anyway.

strugs

I know this is an old topic but, when I found this site, I thought of this thread.

ATRD