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.

Bosch Mobility Ultrasonic Sensor Comparison and Cost Analysis Report - ResearchAndMarkets.com February 12, 2018 08:30 AM Eastern Standard Time ...

By simply choosing a wireless sensor gateway for one’s favorite development platform (Arduino, Raspberry Pi or BeagleBone Black) and any of over 20 different types of wireless sensors, the ...