Rain Drop Sensor

A rain drop sensor is designed to sense the presence and intensity of rainfall by measuring the conductivity between traces on a specially designed sensing plate. When water droplets fall on the plate, the resistance between the conductive lines decreases, causing a change in the output signal.
The module typically consists of two parts:

1. Sensing Plate – A PCB with exposed copper traces that detect moisture.

2. Control Board – Contains a comparator and signal conditioning circuitry to provide both digital and analog outputs.

The digital output indicates the presence or absence of rain, while the analog output gives a proportional reading of moisture level. Rain drop sensors are widely used in weather stations, smart agriculture, automatic wiper systems, and IoT-based environmental monitoring due to their low cost, ease of interfacing, and reliable performance.