6. Connect the infrared sensor's `GND` pin to the GND pin on the Arduino. 7. Connect the `OUT` pin of the infrared sensor to pin 8 on the Arduino. ## Working - The ultrasonic sensor measures the ...

Instead, it relies on an ultrasonic distance sensor to detect a hand (or foot) waved in front of the door. An Arduino Leonardo runs the show, sounding a buzzer when the ultrasonic sensor is triggered.

Seeing as Arduino is good for controlling motors and sensors, Randy added a PING ultrasonic sensor to the front of the vehicle too.