Gravity: Steam Sensor

DFRobot Steam (Water) Sensor is an analog moisture detection module designed to sense the presence of water droplets, steam, or surface humidity. The sensing board produces an analog voltage output that increases as moisture accumulates on the detection surface, enabling simple environmental monitoring and liquid detection projects. Direct compatibility with Arduino IO expansion shields simplifies wiring and rapid prototyping. This compact humidity-sensitive detection board provides an inexpensive solution for rain detection, condensation monitoring, and basic fluid presence sensing in electronics experiments, robotics projects, and educational demonstrations.

Note: The new version of the analog sensor port pin mapping has been updated. Refer to the comparison diagram below for the updated wiring configuration.

Figure: Pin mapping comparison for the new analog sensor connector layout

Note: The connector is not waterproof. Avoid placing the cable connector directly into water during operation.

Analog Moisture Detection Principle

This humidity sensing module measures the conductivity changes caused by water or condensed steam on the sensor surface. As moisture increases, the analog output voltage rises proportionally, allowing microcontrollers to determine relative wetness levels. Such behavior enables straightforward threshold detection for rain sensing, condensation monitoring, or surface moisture alerts. The analog signal interface supports flexible calibration for custom trigger points in embedded control systems and experimental electronics projects.

Direct Microcontroller Integration

This compact environmental sensing board connects directly to common controller platforms through an analog signal line, ground, and power supply. Operating at either 3.3V or 5V makes the module compatible with a wide range of development boards used in robotics, IoT prototypes, and interactive installations. Simple three-wire connectivity allows rapid integration into controller expansion shields and sensor interfaces without complex circuitry.

Compact and Cost‑Effective Moisture Sensor

A lightweight 30 × 20 mm sensing board offers an economical approach to liquid detection tasks where high precision humidity sensors are unnecessary. The small footprint allows easy installation inside enclosures, robotics platforms, or experimental devices. Such simplicity makes the moisture detection board suitable for classroom demonstrations, entry‑level environmental monitoring experiments, and quick prototyping of water‑triggered automation systems.

Typical uses include simple rain detectors, condensation alerts, humidity-triggered touch interfaces, and experimental liquid level indicators. The analog moisture sensing module serves as a practical component for rapid prototyping, embedded electronics experiments, and STEM Education projects requiring basic environmental interaction.