An ultrasonic sensor is positioned outside the box to detect the presence of a hand within a four-inch range. Upon sensing an obstacle, it then sends a signal to the Arduino UNO, which ...

The hardware is consists of an Arduino microcontroller (here an Arduino Uno R3) and a pre-wired ... int GLED= 13; // Wet Indicator at Digital PIN D13 int RLED= 12; // Dry Indicator at Digital PIN D12 ...