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.

Posted in Arduino Hacks, green hacks Tagged arachnophobia, Arduino Pro, feature creep, rain barrel, ultrasonic distance sensor ...

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.

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 ...

By reading different values from the sensor, we can detect if is it light , dark or a value between them. Another element that we are going to use on this experiment is Piezo Buzzer. So what is it ?