Water Level Sensor Module – Rain and Leak Detection

The water level sensor module detects water and gives a rough water-level reading through a set of exposed copper traces. It runs on 3.3–5 V and gives an analog output, so it connects directly to Arduino, ESP32, NodeMCU or STM32 boards.

Specifications

Wiring with Arduino Uno

• + to 5 V
• − to GND
• S to A0

Read the value with analogRead(A0). The reading rises as more of the sensing area is wet. With a 3.3 V board such as the ESP32, power the sensor from 3.3 V so the output stays within the ADC range.

Typical projects

• Water tank level indicator with LEDs
• Leak alarm under a washing machine or water purifier
• Rain detector for a window or terrace

Practical notes

The exposed traces corrode if the sensor is powered continuously while wet. Power it from a digital pin and switch it on only while taking a reading; this extends its life considerably. For accurate continuous tank-level measurement, use a float switch or an ultrasonic sensor instead.

Frequently asked questions

Does it have a digital output?

No. It gives an analog output only. To trigger at a set level, compare the reading against a threshold in your code.

Can it measure the exact water level in centimetres?

Only roughly, over the length of the sensing area. Calibrate the analog readings for your own setup.

Is it the same as a soil moisture sensor?

No. The soil moisture sensor has two probes for inserting into soil. This module is a flat board for detecting water on its surface.

What's included

• 1 × water level sensor module

Buying from Anu Electronics

Sold by Anu Electronics, Chennai, with shipping across India. For bulk orders, WhatsApp +91 93454 49314 or email info@anuelectronics.com.