Bluetooth gadget

Hi gadgeteers :)

I know what I want and I know how I want it to work.
I have seen on here and other sites circuits and projects that almost do what I want, but the they are too complex.

Basically I want a keyless vehicle ignition using bluetooth.

What it needs to do:
When my mobile moves into range it will turn on (and stay on).
When my mobile moves out of range it will turn off.

It needs to run from vehicle power or recharge itself from it.
It specifically does not require an app on the subject device.

I normally keep my bluetooth turned off, so it would actually be when it is turned on or off.

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take a look at this.
or perhaps research the toyota key for the prius. it within a certain range will tell the car the operator can push the start button
use rfid. put reader on center console. and keep tag in your right pocket. have an arduino power a relay for ignition
Vastly simpler to do, much shorter range, and much higher security - BT is pretty easy to sniff and clone.
iphillips3 (author)  steveastrouk4 years ago
But if all you can do is pair.
The connection has no functionality, and the ignition gives no external sign that it is on.
Plus, if I am away for any length of time, the unit will be powered off.
So most of the security is situational.
I can buy the bluetooth unit for less than £50, Where do I get an RFID unit for that price?

12 quid.


9 quid.
iphillips3 (author)  steveastrouk4 years ago
The second looks viable with ariel fixed under seat and tag in my back pocket.
How would I get it to operate the relay?
Would the led or buzzer lines be up to the job?
iphillips3 (author)  iphillips34 years ago
How secure are the RFID tags against copying?
iphillips3 (author)  iphillips34 years ago
I was talking to a mate yesterday, he was saying that his wife's work has just started using RFID tags and he can copy hers with an app on his phone.
If that is normal, then anyone in the pub could copy my tag and pinch the bike before i've got my beer :(
iphillips3 (author)  iphillips34 years ago
Also found this.
18 pages......
iphillips3 (author)  steveastrouk4 years ago
And not a computer in sight.
I will only need one relay.
Yeah, that thing I pointed you at is only a reader, hence you need the computer to work out if its yours or not.

iphillips3 (author)  steveastrouk4 years ago
So bluetooth would need the password, and that keeps it secure?
The password would be long and complex, ideally using characters that some devices can't send.
Word will get round that I have a keyless ignition, plenty of people would be aware and after doing something silimar, therefore thieves would get to hear. Obviously if I'm out with the bike then I will have the 'key' on me.
How do I then stop the RFID key being copied?
You can copy a metal key, if its out of ones possession for a few seconds. Press it into a block of plasticine, and miscreant can make a key in a few minutes.

An RFID key isn't that different.

A BT system would broadcast stuff that you could sniff and ALSO clone, unless, like I said, you use a rolling code generator, like Keeloq.125K - code needed at both ends of the link. BT range can exceed 100m. RFID range though, is, without really heroic measures, around 3 foot, tops,
well, this is kind of the same point that was being made about the bluetooth idea earlier. unless you've got the system on the bike configured to use a non-default pairing password then anyone would be able to pair to the device when they see the bluetooth network available.

your response to that is that no one would know what the bluetooth network was for so even if they could pair to the bike it wouldn't matter.

the same would apply to the RFID tag. for someone to effectively steal the bike, they'd have to know you have an RFID tag on you AND know that the tag turns the ACC power on your bike on.

either option relies on security by obfuscation anyway, so why not go with the easiest one? RFID systems (even the higher range ones) use a lot less power than bluetooth (AFAIK).
I suppose you could do it by sending a second access code OVER the BT channel, and using a rolling code in that.

,....but ain't RFID simpler ;-)
plus, with the RFID option you could get an RFID chip installed in your butt cheeks and not have to worry about forgetting it somewhere
AND when you clench 'em it masks the signal. Pass wind, and you start your bike....
You still need a small computer to read the data stream -an Arduino leonardo would do that nicely.
So you want a bluetooth receiver in the car and when it connects to your specific device it needs to automatically turn the ignition on. So you'll need a small computer like a Rasberry Pi built into the car running off the battery and programmed to sync with your phones bluetooth.

You'll need the Pi to activate relays that bypass the ignition and turn the power on to the car then another relay to activate for a determined amount of time to turn the car over. All of this would make your car extremely easy to steal. Bluetooth isn't a secure means of transmission and is easily hacked. Just about any phone that finds the open port from your car could sync with it and activate your system.

Other considerations would be the amount of power being drawn from the system as it's waiting to get a signal. So you'll need to know how much power the total system draws so you don't kill your car battery.
iphillips3 (author)  mpilchfamily4 years ago
Far too complex and power hungry :)
Not a car, bike.
Only needs to turn switched live on so only one relay.
Doesn't need anything on the bike to say that it is 'live', I can tell that that from the phone since it is paired.
A search for 'bluetooth relay' finds several boards that almost do the job, but they all seem to turn off again after 5 minutes max, would prefer not to have to mess around with extra logic to keep the ignition on.
If it can't handle enuff current that isn't a problem, I'll just use an external 30A relay.
Ability to have reduced range with be a bonus, 50cm would be ideal.

PS: I'll be using a raspberry pi as engine management/media server/satnav on the trike :)
Then look into using RFID. It won't be on you phone unless you attach an RFID tag to it.
iphillips3 (author)  mpilchfamily4 years ago
That is an option, however from what I understand the range is only an inch or 2 and I would have to specifically swipe the tag.
I am specifically looking for an option that activates when I move into range, I don't want to take any action that an observer could identify as turning the ignition on.
After further thought, the ideal range would be 1-2m.
If an RFID unit could be setup with that range and set so that it keeps the relay active as long as the tag is in range, then yes, that would be a better option.
Read up on RFID. There are more options then what you think. RFID has both active and passive tags. It all depends on the frequency range in use. There are both active and passive options for 1 to 2 meters in range. There are even options that go up to 200 meters. These tags are often using for tracking shipping containers through ports.
iphillips3 (author)  mpilchfamily4 years ago
Ok, so where would I get a system with a 1m range?
The 125Khz ones could be arranged to do that, its all down the antenna design and orientation. Lots of experiment required.
iphillips3 (author)  steveastrouk4 years ago
So what is it about RFID that makes it a better option?