The Capacitive Soil Moisture Sensor is a corrosion-resistant sensor designed to measure soil moisture content based on capacitance variation. Unlike resistive sensors, it does not expose metal probes to the soil, resulting in longer life and stable performance. It is ideal for smart irrigation systems, agriculture automation, and IoT-based plant monitoring projects.
Core Sensor Specifications
• Sensor Type: Capacitive soil moisture sensor
• Measurement Principle: Capacitance-based moisture detection
• Output Type: Analog voltage
• Corrosion Resistance: Yes (no exposed electrodes)
Electrical & Interface
• Operating Voltage: 3.3 V – 5 V
• Output Signal: Analog
• Interface Pins: VCC, GND, AO
• Logic Compatibility: 3.3 V / 5 V ADC compatible
Performance Characteristics
• Stable readings over long-term use
• Less affected by soil salinity compared to resistive sensors
• Suitable for continuous monitoring
• Requires calibration based on soil type
Physical Characteristics
• Sensor Body: PCB-based probe
• Coating: Moisture-resistant protective layer
• Form Factor: Slim probe for easy soil insertion
• Lightweight and compact design
Compatibility
• Arduino Uno / Nano / Mega
• ESP8266 / ESP32
• STM32, AVR, PIC microcontrollers
• Raspberry Pi (with external ADC)
Key Advantages
• Long lifespan due to non-corrosive design
• Accurate relative moisture measurement
• Low power consumption
• Easy integration with microcontrollers
Technical Insights
• Measures relative moisture, not absolute water content
• Output voltage varies with soil dielectric constant
• Calibration improves accuracy for specific soil types
• Should not be fully submerged in water
Applications
• Smart irrigation systems
• Automatic plant watering
• Agricultural monitoring
• Greenhouse automation
• IoT-based soil analysis projects
Pro Tip
• Calibrate dry and fully wet soil levels in software
• Insert the probe vertically for consistent readings
• Avoid bending the PCB during installation
Package Includes
• 1 × Capacitive Soil Moisture Sensor Module