That’s right, these parking sensors are powered by an Arduino board, and the only extra components that were used in the project are a HC SR04 ultrasonic sensor, an active buzzer, and jumper wires.

Arduino Parking Lot Attendant. 25 Comments . by: Mike Szczys. October 15, 2012. Title: ... You could use a magnetic sensor as the cars are all metal and you could detect the eddy currents.