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Rain Sensor (FC-37 + LM393)

Sensor

Detects rain as water drops on its conductive-track plate lower the resistance; the board gives the rain intensity as an analog value and as a digital output with an adjustable threshold.

Specifications

Supply voltage

3.3 - 5V DC

Output

Analog (AO) + digital (DO)

Digital output

LOW when wet

Comparator

LM393

Threshold adjustment

Trimmer

Plate size

54 x 40 mm

Pins

VCC, GND, DO, AO

Shop prices

• Robo90In stock29.76 ₺
• Modül ElektronikIn stock32.80 ₺
• HatfonIn stock36.75 ₺
• RobocomboIn stock39.00 ₺
• Robolink MarketIn stock40.50 ₺
• Direnc.netIn stock41.84 ₺
• SAMM MarketIn stock44.65 ₺
• MotorobitIn stock45.45 ₺
• HobiDevreIn stock46.08 ₺
• ElektrovadiIn stock60.12 ₺
• KomponentciIn stock63.92 ₺
• F1 DepoOut of stock24.00 ₺
• RobotistanOut of stock40.80 ₺
• RobotzadeOut of stock53.40 ₺

Prices read from the shops' pages on 22 October 2026. Prices and stock may have changed since; check at the shop before you buy.

Projects with this part

• Rain Alert and Automatic WindowBeginner40 minA setup that sounds an alert and closes the window by itself when it starts to rain: when water drops land on the rain sensor's plate, the buzzer plays a ding-dong three times, then a servo slowly closes the window. Some time after the plate dries, the window opens again. The sensor board is powered from one of the Arduino's pins and switched on only while measuring, so the plate does not corrode by electrolysis. It teaches turning an analog reading into a percentage, using two separate thresholds for rain and dry, timing a period (that starts over if the plate gets wet again) and turning a servo slowly, one step at a time. The Servo library comes with the Arduino IDE; there is nothing to install.Open project