Distance Activated Keyless Ignition

Hi! I want to build a keyless ignition "relay" for an old Jeep, so as to not need to carry around keys and somewhat as an anti theft device, as it has no doors. The plan is for it to enable a start button whenever a previously paired phone is detected and at a close distance, say 5 meters, or simply actively connected. Pressing this start button would enable the ignition and turn the starter while being held, and that button or maybe a smaller one would stop the engine. Losing the conection with the phone should not stop the engine, for security reasons! (though I might add an SMS enabled kill switch). A well hidden button would allow the engine to be started without the need for a cell phone, in case its battery dies, and the 12v power outlet would be always on so that phones can be charged if in need. How do you think I should implement the wireless part of this? I was thinking about BLE, so as to be able to use my cell phone and not need to carry around any extra hardware (hence, keyless) though I've never worked with any wireless technology plugged into the arduino before... Is it possible to make the BLE device to ask for a password or pin number when connecting to a new device? (not the default 0000!) I'm no expert but I've been using arduino for a while, mainly working on a solar mppt charger now and learning about three phase dds, so the main focus of my question is on how to implement the wireless part and what technologies to use. Bluetooth? Bluetooth Low Energy? RFID? NFC? WiFi? Thank you very much :) Best regards, Willy / Wiky5

This can be done with bluetooth, RFID, wifi or whatever you prefer. There are some things to consider when choosing: Power consumption must be as low as possible so the system can work for several weeks if the car is not in use and placed in a garage. If you want to use your phone, it's best to write an app for locking/unlocking. That way you can add as much security and login credentials as you want in the app directly.

Depends on your car system...

many modern car security systems require the ignition key to be in close proximity to the key socket since they have a short range passive RFID device to identify that key - and no other.

bypassing all that would be tricky.



Thank you for your answers. It is an old and completely "analog" vehicle and I want it not to have a normal keyed ignition as hardwiring it is very easy. No disassembling required. I'll keep on investigating about BLE then, and I hope writing an app for the phone is not that difficult. Regards, Willy

Does they key also unlock the steering column? Or is it older that even, with the key on the dash?

I hope writing an app for the phone is not that difficult.

Which phone? Writing an app for an iPhone is not that difficult. Getting it TO the phone requires that you pay Apple $99 per year for the privilege of loading the app you wrote to the phone you bought. AND the app will expire after a 90 day period of time, and no longer work.

The only way to create a non-expiring app is to make it available in the app store, and that requires a long process of Apple reviewing your code (and you re-writing it, and Apple reviewing it again...), before they agree to host your app in the store.

I suggest you to use a rfid module, that would be easy, you'll also need a relay module,with more then 1 relay if your car needs multiple turns of the key to start the engine

And about the internal cip (if you have one like I have) it is right your key and you can remove it and place it, hidden(inside), after the reader.

You can also go fancy and use a pir sensor to detect if there is someone in your car witch doesn't use the rfid after a period of time or another alarm system using arduino

If you're still thinking about the mobile method , if you have an android phone it would be super easy to write an app and use it, but you always need to keep the bluethooth on and the app turned on too, somehow you'll need to keep that app in memory of you don't want to pull the phone out of your pocket every time.

I also think that your phone have a unique bl id that you can scan with your module and do the trick

Hi, Thank you all for your answers!

The vehicle is a 1946 Jeep, so no fancy locks and stuff.

I also thought about RFID, but I'm not really sure about using that... Bluetooth can be hidden inside the engine compartment in a secure box, while RFID requires close proximity. I also don't want to hinder the original looks of the vehicle, apart from replacing the key with a "Start/Stop" button.

I have 110A mosfets and some dislike towards relays, so everything will be solid state, apart from the huge starter motor relay which would be excessively difficult to replace with mosfets.

My phone is a Lumia (Windows). I guess they won't ask me to pay anything to load the app, and maybe I don't even need to put it on the App Store, as (i believe) they can be loaded directly onto the SD card or internal memory with a computer.

Basically, I want the arduino to be a master electrical switch and control the release of the hood latches, all activated via bluetooth (low power, larger range) or possibly RFID (higher power, very close range) and have it control the logic of a few things, such as "if the engine is off, holding the start button cranks it, if on, pressing it kills the engine", though that's easy. Having a "Start/Stop" button on the bluetooth would also be nice, though I first need to learn to interface Arduino with BLE and write apps for my phone.

My original idea was to activate the start/stop button whenever the phone is close enough, though that might be difficult to implement...

Thank you all very much.

Best regards, Willy

RF sealed in a metal box could be tricky. One other alternative for the platform might be a wifi based web server - and using your phones browser to lock/unlock the car.

It's going to be tricky protecting a 1946 'anything' from hot wiring...! All the ignition circuits are exposed under the hood, accompanied by a hill start.

Just a thought.

lastchancename: It's going to be tricky protecting a 1946 'anything' from hot wiring...! All the ignition circuits are exposed under the hood, accompanied by a hill start.

A remote car control may turn out as a theft aid, without making hands dirty :-]

lastchancename & DrDiettrich, that’s why I want to use something that can be hidden under the hood ;). No one here would have either enough knowledge or the will to hack a wireless system, having to guess the commands being sent and all.
I guess enough signal might be able to pass through the vent holes above the hood next to the windshield, or under the vehicle, to enable a satisfactory connection…