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key-less entry / key-less ignition (arduino based) Answered

Hey guys, I want to make a key-less ignition and a key-less entry on my car. I have no doubt that arduino can be the core for this system. as of now, I am thinking of using arduino UNO to control everything and an RFID unit for the key-less entry. I know that there are many types of RFID, some for sensing close like tags or cards, and some for larger distance like 10 to 20 ft. the one I need will have to be able to read a module from around ten feet of the vehicle. I am debating whether to automatically unlock the vehicle when the module is within range or put a button on the door handle and trunk so that they will unlock if the key is in range. I decided that the push button ignition will include a toggle for ignition and a push button for start. The ignition switch will be wired through a relay so that the arduino can "enable" ignition when the key is present. I want all redundant systems so I will wire the ignition in parallel so the stock key will still start and run the car. I post this for advice, comments, and any improvements you guys can think of. My budget is $200 maximum. My goal is to make it for under $150. Any help would much appreciated.

- Jordan



6 years ago

Some upper end cars unlock as you and your key bob approach, already do this feature.  It may not be for sale to you.  
I would ID the car that has such a feature, then go see a dealer to
have it demonstrated. 


Thank you for the advice. I am already aware that this exists, and found some after market kits that adds these features to a car. The price on these kits are ugly and I firmly believe that the same outcome can be achieved for much less money and some mental grease.

Lets think how this function works ?

The car needs to send out a query signal at regular intervals until a fob responds
with the exchange key passwords.

The fob would not be a query candidate because of battery usage.
This relegates the car to query for a fob response and the fob must detect
a car and respond with the proper key.

Actually regular query intervals aren't required. if you have a button on the car to unlock it then only make the system send ping your card when the button is pressed. If it detects the correct device is present then it will unlock, if not, then pressing the button would do nothing more than send that single query signal. No need to waste battery by leaving it constantly on.

I agree. There are many RF-ID fobs in the market that have excellent range. It would be a matter of pairing a RF-ID fob with the controller RF-ID module. Most use a serial such as UART to output a signal when activated. Each time it reads an RF-ID, it will output a signal containing the information. The arduino program will decide if it is the correct code and if so, execute the rest of the code, being enable the unlock button on the door. Again some RF-ID are designed to read cards or key chains and are only effective within inches of the device, while others are battery powered and have extended range like say, ten feet.

Oh, and I think that I will have a membrane button on the handle or by it that unlocks the car if the key fob is in range. I don't want my car to unlock if I just walk by it.

YAJABPI You Are Just A Button Pressing Impresario.

The car simply Locks again if you walk back out of range or if you take too long
to touch the car.

Otherwise it is a standard key fob entry that all new cars come with.