IO extender feature - immobiliser

If you have ideas for a new board, for new features for existing boards, or want to suggest new applications for the I/O Extender, this is the place to post.

IO extender feature - immobiliser

Postby Rod S » Tue Sep 14, 2010 6:10 am

Aftermarket alarms/immobilisers use hard wired relays to interupt two or more key circuits. Lots of additional wiring, hidden relays, all things to go wrong.

Modern cars (in the European market at least) use CanBus to verify immobiliser status and often other key digital devices before allowing the ECU to run. Obviously that is the other extreme.

Instead, would it be possible to have an aftermarket alarm/immobiliser output, instead of operating a relay, just go into a low level input circuit on the IO-x creating an instruction to either enable/disable the MS2 (through a CanBus instruction) or enable/disable any key output the IO-x was being used for.

Did that make sense ???

Rod.
Rod S
 
Posts: 310
Joined: Mon Sep 06, 2010 4:03 am
Location: Rural Suffolk, England, UK

Re: IO extender feature - immobiliser

Postby jbelanger » Tue Sep 14, 2010 6:34 am

This has been suggested and I have thought of implementing something like this with an RFID tag. The IOx would read the RFID and send an ok signal to the MS. If the MS doesn't receive the ok signal within a certain time interval it would simply shut the engine. Or it could be required to have the ok signal to start the engine.

Jean
Image
jbelanger
 
Posts: 3620
Joined: Sat Oct 03, 2009 12:24 pm
Location: Quebec, Canada

Re: IO extender feature - immobiliser

Postby Rod S » Tue Sep 14, 2010 8:59 am

RFID tag sounds like a good idea for someone starting with nothing, I was thinking along the lines of just an external logic input from an aftermarket alarm/immobiliser - it just gives 12V to operate a relay if dis-armed and 0V if armed or immobiliser operated.

The one I intend to use is insurance company approved (Thatcham Category 1 over here) but would normally operate relay(s).

Rod.
Rod S
 
Posts: 310
Joined: Mon Sep 06, 2010 4:03 am
Location: Rural Suffolk, England, UK

Re: IO extender feature - immobiliser

Postby jbelanger » Tue Sep 14, 2010 12:26 pm

What I had in mind would also work in this case. The way I wanted to implement this was to have a logic input on either the MS or the IOx with the option of having an RFID in the IOx.

The issue I see with the logic input is that you can simply cut a wire and ground it to defeit the immobiliser. The advantage of the RFID would be that cutting a wire and grounding it would not work since there is a need to have some communication between the IOx and the MS and between the IOx and the RFID reader.

Jean
Image
jbelanger
 
Posts: 3620
Joined: Sat Oct 03, 2009 12:24 pm
Location: Quebec, Canada

Re: IO extender feature - immobiliser

Postby aarc240 » Sat Feb 19, 2011 8:10 pm

You are on the right track with the RFID tag as the primary enabling device.
The idea Rod has is also necessary in Australia as there is no way I could get my insurer to give a discount based on the RFID enable alone.
Accept an input from an existing approved alarm also and you've got it covered.

Interestingly, a 25yo Holden Commodore we have has exactly that. although with an equivalent of the RFID tag. It won't even crank over with the valet key even though that will unlock the steering and operate the ignition switch [the accessory circuits do work!]. When the alarm activates, everything but the alarm and flashing lights are dead. What amazes me is that this was fitted by General Motors Holden prior to delivery in 1986!!!
aarc240
 
Posts: 95
Joined: Sat Feb 19, 2011 5:01 pm


Return to Wish List & Requests

Who is online

Users browsing this forum: No registered users and 1 guest

cron