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.

The compact module helps us to test HC-SR04 modules quickly without a costly microcontroller setup (no code lines/solder smokes) and/or build an extremely portable minimalistic sonar device. I have ...

A low-cost (~$100), do-it-yourself (DIY) ultrasonic water level sensor/datalogger has been designed, constructed, and tested for use in education, citizen/community science, and research settings. The ...

Through the use of an Arduino, ultrasonic rangefinder, Ethernet shield, and twitter account, whenever the toilet is used a counter goes up. Calculate that against your gallons per flush and you ...