Solution for proximity kill switch

Hello everyone. I'm working on a simple kill switch for my motorcycle which will close the circuit when I'm within a 3-5 meter range. I've been looking into different active rfid solutions, but I haven't pinpointed exactly what I need. First off, before I get ahead of myself, is an active rfid tag the way to go (discretely mounted on my helmet), or should I be looking into something else—bluetooth for example?

I suspect that no RF based approaches are going to give consistent triggering distances, especially in the electrically noisy environment around a typical motorbike. Bluetooth will typically work over a distance of a few meters, but it might be significantly more or less than this in some circumstances. Would it be a problem if it triggered prematurely, or failed to trigger over a long distance?

sXule:
I'm working on a simple kill switch for my motorcycle which will close the circuit when I'm within a 3-5 meter range.

Is this intended to be an active decision or passive. If active is OK then perhaps you could get the user to press a key-fob device to cause the switch to trigger. It's not a whole lot different from expecting them to carry a radio device that they don't need to touch.

...R

Can you say what the use is please?
Im baffled.

Let me be more specific. All I'm trying to do is verify that the owner is present before the bike will start, and if the owner is no longer within range of the device it will start a timer to kill the bike. I want there to be a fob-like device to be carried by the driver, just as long as it doesn't require a swipe. Doesn't matter how accurate the triggering distance is by the way.

I'm struggling to imagine the use cases where this makes sense. You're planning to walk away from your bike leaving the key in the ignition?

I think all the solutions you're looking at would require an active transponder of some sort. What sort of battery size/life would you be aiming for? Maybe something based on an nRF24L01+ transceiver would work - they're very low power consumption, and if you only power them up e.g. once a minute they would only need a few mW. You'd need a microcontroller to drive it though, so you'd probably want to look at standalone low power consumption Arduinos for that - they're still going to need big batteries or regular recharging though - the last thing you want with something like this would be the transponder dying on you.

Is there not a risk here of the engine suddenly dying when travelling at speed.

PeterH:
I'm struggling to imagine the use cases where this makes sense. You're planning to walk away from your bike leaving the key in the ignition?

I think the OP meant that if the owner (or carrier of the tag) isn't close to the bike, the engine won't start.... so someone attempting a hot-wire would be unsuccessful.

JimboZA has it right. The device would prevent a hot wire, and in the case someone knocks you off your bike and rides away, the engine would kill within 30 seconds to a minute. The device will be powered by the motorcycle battery, but only when the ignition is on, so the battery won't drain. It's an anti-theft device essentially.

My initial idea was to simply have a passive rfid tag with a reader to start the bike, but this wouldn't allow for the automatic kill function in the case you get jacked. That's why I thought an active rfid tag might work. The tag/fob doesn't have to be super small, but I'd like it to at least fit on my other key chain or on the back of my helmet.

What about the sort of kill-switch they have on outboard motors. A little plastic gadget forces a connection in the ignition circuit when it is inserted. It is tied to a wrist cord and if you fall out of the boat the plastic gadget gets pulled out and the engine stops.

In your case the potential thief would need to have the correct "gadget" to get the bike going. If you choose an uncommon connector that's very unlikely.

You need to beware of the thief that demands you hand over the gadget (whether it's an RFID system or anything else). I heard a story (may not be true) that thieves took the owner's finger so they could start an expensive car with a finger print anti-theft device.

...R

Something like this would be quite easy to install and probably cheaper than any DIY solution based on Arduino and wireless transponders:

Autowatch 68Hi AntiHijack System

Having been the subject of an attempted hijacking of my motorbike last week ... the (not) nice chap wanted to swap his knife for my pride and joy i know exactly what the OP ( sXule) is thinking of ... and its a shame i couldnt come up with a ready made solution either ...
i as thinking along the same lines as a proximity device too .. tag sewed in my jacket perhaps

did you come up with anything ?

i dont like the kill switch idea and i dont want to hijacker to get too far before the engine cuts but i would like a horn or sounder and the hazzards to come on within say 10 seconds

im glad i didnt let him intimidate me i took 4 wounds in my back .. but id rather there was a better option than just give up the bike (£3000) or get stabbed

Joanne

joanne1234:
Having been the subject of an attempted hijacking of my motorbike last week ... the (not) nice chap wanted to swap his knife for my pride and joy i know exactly what the OP ( sXule) is thinking of ... and its a shame i couldnt come up with a ready made solution either ...
i as thinking along the same lines as a proximity device too .. tag sewed in my jacket perhaps

did you come up with anything ?

i dont like the kill switch idea and i dont want to hijacker to get too far before the engine cuts but i would like a horn or sounder and the hazzards to come on within say 10 seconds

im glad i didnt let him intimidate me i took 4 wounds in my back .. but id rather there was a better option than just give up the bike (£3000) or get stabbed

Joanne

Joanne , this is an old thread.
Not being a biker myself can you explain what you are trying to achieve. ?
I have been mugged and injured at knife point as a pedestrian before.

Take out bike insurance???

I know its an old thread Boardburner2 the requirement is the same ans i was wondering if the OP found a solution ready made or otherwise

bluejets unhelpful thanks yes i am fully comp but id rather not try and claim when dead its hard enough when alive

An RFID in a back pocket with a hidden reader in the seat might work. Allows 'run' immediately it's detected , but shuts down after a TBA delay when detection fails.

Not suitable for trials bike riders.....

Allan.

Get off the bike, and pull out some heat. Aim for the center of mass, and claim self defense.

joanne1234:
...i took 4 wounds in my back...

CrossRoads:
...and claim self defense...

Not a huge leap to make that claim. Especially given the fact that a single knife wound can be fatal.

joanne1234:
i dont like the kill switch idea and i dont want to hijacker to get too far before the engine cuts

Were I in your shoes I would try for a system that...

Has successively degraded performance (engine keeps running worse and worse until finally won't run). I suspect interrupting the ignition spark would work very nicely. That way, if the system accidentally triggers, you have time to move to the side of the road where you can bypass / remove the system until the problem can be fixed.

Provides tracking data...
https://www.google.com/search?q=arduino+gps+sms+tracker
Many people have successfully built such things. I believe you can even still purchase ready-made hardware (I did but that was more than a year ago). Armed with such a device, were your bike to be stolen, you could simply command the system to send tracking data to your favourite police officer's phone.

FWIW i used to fit COBRA systems to upmarket cars which used a motorised valve in the fuel line but if you use a delay to shut off there is a risk of causing an accidentt for which you could be liable.

One of the reasons for the fuel valve is that it requires considerable work to get around it , sometimes we used two , hidden away. There was one type that was actually inside the fuel tank.

sorry i seem to have c****d up my thread somehow.Deleted some stuff.

Try to repeat.

The police have trap cars that gradually slow a car rather than stopping it.
The risk of a sudden stop could cause an accident for which you could be liable.
However they are generally on hand to apprehend.

These are somewhat difficult to fit to motorcycles however and they are more likely to have an uncontrollable crash than a motor car.

I like crossroads idea but unfortunateley am in the UK.

One of the problems with a delayed stop is the the thief has been known to return to 'punish' the owner.