Soil Moisture Sensor Specifications

General

• Type: Resistive soil moisture detection module
• Components: Corrosion-prone probe + comparator circuit (LM393)
• Output Type: Analog (AO) and Digital (DO)
• Use: Detects water content in soil for plant/irrigation projects

Electrical

• Operating Voltage: 3.3 V – 5 V DC
• Current Consumption: ~5–30 mA
• Analog Output: Voltage proportional to soil moisture
• Digital Output: HIGH/LOW based on threshold
• Comparator IC: LM393
• Sensitivity Adjustment: Onboard potentiometer

Performance

• Detection Range: Depends on soil type; typically 0–100% relative moisture
• Response Time: Fast (sub-second)
• Output Stability: Good for basic monitoring; not suitable for precise scientific measurement

Interface / Pins

• VCC – 3.3–5V
• GND – Ground
• AO – Analog signal output
• DO – Digital signal output (threshold controlled)

Physical

• Module Size: ~30 × 15 mm (control board), ~60 × 20 mm (probe)
• Probe Type: Two-pin conductive resistive probe
• Cable: 3-wire Dupont cable (commonly included)

Features

• Adjustable moisture threshold using potentiometer
• Onboard LED indicators for power and output status
• Simple plug-and-play design for Arduino, ESP32, and Raspberry Pi
• Works well for automatic watering and soil monitoring systems