Rain Drop Sensor

Product Description

Rain/Water Sensor Module

Operating Voltage: 3.3V to 5V.
Adjustable sensitivity.
Digital and Analog outputs.
Digital output can drive up to 100mA (Buzzer, relay, etc).
Power LED and DO status LED.
Digital output will be low when water is detected.
The Analog output acts like an variable resistor and will change in value between 100kΩ (wet) and 2MΩ (dry).

Links
http://www.instructables.com/id/Arduino-Modules-Rain-Sensor/