A resistive soil moisture sensor that reads the water content of surrounding soil by measuring electrical resistance between its two probes. Wetter soil conducts more easily (lower resistance), while dry soil conducts poorly (higher resistance) — giving you an analogue voltage output proportional to moisture level.

Part of the DFRobot Gravity sensor range, this module features a plug-and-play 3-pin analogue interface and works at both 3.3V and 5V, making it compatible with Arduino, Raspberry Pi, and other microcontrollers. The probes feature an Immersion Gold (ENIG) surface finish for improved oxidation resistance and longer life compared to standard HASL plating.

Key Features

• Gravity Interface – 3-pin analogue connector for plug-and-play wiring
• 3.3V and 5V Compatible – Works with Arduino, Raspberry Pi, and other boards
• Analogue Output – 0–4.2V output proportional to soil moisture level
• Immersion Gold (ENIG) Finish – Superior oxidation resistance for longer probe life
• Low Current Draw – Just 35mA

Ideal For

• Automated plant watering systems
• Garden and agriculture monitoring
• IoT smart garden projects
• STEM education and environmental sensing

Specifications

• Power Supply – 3.3V or 5V
• Output Voltage – 0–4.2V (analogue)
• Current – 35mA
• Pin Definition – Analogue output (blue), GND (black), Power (red)
• Surface Finish – Immersion Gold (ENIG)
• Dimensions – 60 × 20 × 5mm

Package Contents

• 1× Soil Moisture Sensor
• 1× Analogue Sensor Cable

Resources

• Product Wiki
• Schematic (PDF)
• Sample Code