The car you drive says a lot about who you are as a person. If you drive a Subaru Outback, there is a good chance you live in Colorado and own a golden retriever. If you drive a Toyota Corolla, you probably don't care about cars at all and have never changed your oil. If you drive a BMW, you treat the interstate as a race track and have never touched your turn signals. To help BMW drivers out, Marc Radinovic created a device that provides reinforcement training for turn signal usage.
It may be hard to believe, but every BMW comes from the factory with turn signals installed as standard. A BMW's manual even explains to owners exactly how to operate those turn signals. But if we are to believe the running gag in car circles, BMW drivers can't seem to figure out how to work the turn signal stalk. This device solves that problem. If the driver turns the wheel without first activating a turn signal, the device will scream at them. To stop the screaming, they must give the turn signal stalk a little nudge. To balance out the negative reinforcement, the device will also provide encouragement for turn signal usage.
This device actually consists of three individual boards: two Arduino Nano 33 BLE boards and one Arduino Uno WiFi. There is also a Raspberry Pi single-board computer, which plays the sound effects through the car's stereo. Each Arduino Nano 33 BLE has a built-in 9-axis IMU (Inertial Measurement Unit) that can detect movement. One attaches to the steering wheel and the other attaches to the turn signal stalk. Both communicate with the Arduino Uno WiFi. If steering wheel movement is detected without turn signal stalk movement, then the Arduino Uno WiFi tells the Raspberry Pi to play one of a few different angry sound effects.
The boards are all taped in place and Radinovic could have used far less hardware if he had gone through the CAN bus, but his BMW is new and he didn't want to go hacking up the car just for this silly video.