Adafruit Simple Water Detection Sensor with Digital Output

Keep wet things wet and dry things dry by detecting when the dry things get wet by accident! This palm-sized cherry-red water sensor is simple and easy to implement in your wet-dry-sensing project.

Usage is very simple: connect the minus pin to ground, connect the plus pin to 3 to 5V DC and then the output signal pin goes to your microcontroller.

The sensor has a very lightly biased transistor connected to two long sets of interlocking traces. When even a tiny bit of water lands on the PCB and touches two of the traces, the transistor turns on, setting the output pin high.

The output voltage varies slightly based on the amount of water detected, but it is recommended to use it as an "on or off" type sensor. Avatar water-bending skills not included!