Wristband RFID Unlocks Car Door And Starts Engine

[João Ribeiro] is an electronics engineer by day, but in his free time he likes to ply his trade on everyday items. Recently he’s been integrating his own microcontroller network to unlock and start his car via RFID. In addition to the joy of pulling apart the car’s interior, he spent time designing his own uC breakout board and developing an RFID reader from a single chip.

He’s working with a 1988 Mercedes that has very little in the way of electronics. It sounds like the stock vehicle didn’t even include a CAN bus so the prelude to the RFID hack had him installing a CAN bus network made up of two microcontrollers. One reads the velocity and RPM while the other displays it on the tachometer. When he began the tag-based entry system he used an RFID reader module for prototyping, but eventually built his own reader around the TRF7960 chip. This included etching his own receiver coil which was mounted in the side-view mirror bracket. To unlock the doors he holds the bracelet up to the mirror and the vehicle lets him in. The video after the break starts with a demonstration of the completed project and moves on to some build videos.

We certainly like the idea of using a bracelet rather than implanting the tag in the meaty part of your hand.

19 thoughts on “Wristband RFID Unlocks Car Door And Starts Engine

  1. Looks like a Mercedes 190 Series also known as “Baby Benz” in germany because it was the smallest model available at it’s time. Definetly no CAN bus. This (and the w124) are the last real Mercs. BTW: Either it’s got over 1 million kilometers (no problem at all) or the odometer has been messed with (judging by the look of the drivers seat).

    1. Yes the odometer had a hack also. Actually it was one of the first hacks on the car as it came with the odometer stuck at 313000 km. So at least it has that, but I am sure that the previous owner broke it while trying to take back some km. My thought was to put it back to zero and start from there. That’s like a reborn for the car I guess.

  2. CAN bus wasn’t in cars until circa 2003~2004. Until 1996 every manufacturer used their own proprietary diagnostic interfaces and codes.

    1995 is a unique year for many vehicles, often termed OBD 1.5. Codes and most interfaces still proprietary. Some vehicles used the OBD 2 connector but not OBD 2 codes and communication protocol. On GM vehicles for 1995, the “paper clip trick” does not work to blink codes on the check engine light.

    There are a few diagnostic devices that will read codes and other data from most 1982 to current vehicles. Innova makes two models and Acctron makes at least one.

    SnapOn recently discontinued their modular system (the big red and black box with plug in modules and PCB “keys” for various vehicles), so only pick up a used one if it comes with everything you need for any 2005 or older vehicle you’ll be working on.

    1. Awesome commercial, I have never seen it! That’s one of the reasons that I have to increase the range of the antenna, because it is less than 3 or 4 cm when inside the side mirror. So unless it is a chihuahua, I am afraid that I would be rubbing the poor dog against the car with no result.

  3. If you want to do this with any OEM remote system ever made(tip):MICRF007

    Good luck dumping code generator algo from BCM or ECM though. Making a custom system is easier than this though..

    1. Yap… The engine sound is by far not the best engine sound ever made, but it is working and most of the times working on reused vegetable oil (one of the reasons that my father and I bought the old Benz). I hope one day I could mount this system on a proper V8, but until then, this will work

  4. Implanting the RFID in your hand makes it a lot harder to hand the key to a valet if you’re somewhere that only has valet parking. But it does mean you can’t forget your keys or lock them in the car.

    I’d prefer a combination-lock car door opener for convenience, but unfortunately the last time I bought a car, that option was only available on the package with the really expensive trim and the bigger engine that gets lower gas mileage, so no luck. But at least it’s new enough I can try all the OBD tools that didn’t exist on the mid-80s van it replaced.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.