Build a smartwatch remote for your car with Arduino

Maker controls his Honda CR-Z using a Pebble watch, an Android phone and an Arduino. 

The advent of high-tech, connected vehicles and wearable gadgetry has provided drivers with a new way to remotely unlock their doors, start the ignition and even find parking spots. Take for instance, Hyundai, whose Blue Link app now fully supports Android Wear devices and enables users to do everything from flash its headlights to call roadside assistance.


However, Mika Wee didn’t own the latest and smartest car. And so, he decided to take it upon himself to bring this functionality to his 2013 Honda CR-Z with the help of Arduino and 1Sheeld. Using his Pebble Steel watch, he was able control its hazard lights, flash its high beams and honk the horn, among a number of other things — though he could do it all from his Nexus 5 smartphone as well.

“The idea of this project is to be able to turn on/off lights (or any electrical component) of a car without being inside the car, or physically pressing dashboard buttons/switches,” Wee writes.

The Maker used a bunch of shield-based components to simplify the project, including a DFRduino (ATmega328), a 1Sheeld (ATmega162) as an input receiver to communicate with the phone, and a relay shield as the output to complete the circuit.  Aside from that, he created the watch’s menu with the help of PebbleTasker.


“The next step is to find out which wire in your car does what. Now this is completely dependent on the car that you have, as every car would have a different circuit,” the Maker adds. “I used a multimeter and the help of the car’s service manual to find out which wires/relays conduct electricity when a switch/button is pressed. This tells me which wire/circuit I’m looking for. Then, I tapped relay wires into that circuit to simulate a ‘button press.’ This is not intrusive as I do not go into ECU, OBDII or CAN bus hacking. I merely simulated a ‘button press.’”

Intrigued? Head over to the project’s page on where Wee shares a step-by-step breakdown along with the necessary code and schematics. Watch it in action here.

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