Soil Moisture Sensor Module
🌱 Soil Moisture Sensor Module (Resistive Probe + LM393)
Overview
A straightforward and reliable soil moisture sensing module, which combines a fork-style resistive probe and a signal-processing board with LM393 comparator. It provides both analog (moisture level) and digital (threshold‑based) outputs, making it ideal for agricultural monitoring, smart irrigation, gardening projects, and more.
Key Features
Operates on 3.3 – 5 V DC
Dual outputs: AO (analog) and DO (digital)
Onboard potentiometer to adjust digital threshold
Status LEDs: red (power) and green (digital output)
Uses fork-style resistive probe, about 60 × 20 mm
Compact PCB (~32 × 14 mm) with mounting hole
Low power consumption (~15 mA)
Technical Specifications
| Parameter | Value |
|---|---|
| Supply Voltage | 3.3 – 5 V DC |
| Operating Current | ~15 mA |
| Analog Output (AO) | 0–5 V proportional to moisture |
| Digital Output (DO) | 0 or 1 based on adjustable threshold |
| Probe Size | ~60 × 20 × 5 mm |
| Board Size | ~32 × 14 × 6 mm |
| Temperature Range | –40 °C to +85 °C |
Wiring with Arduino Uno
| Module Pin | Connect To |
|---|---|
| VCC | 5 V from Arduino |
| GND | Arduino GND |
| AO | Analog input (e.g., A0) |
| DO | Digital input (e.g., D2) |
⚠️ If using DO, ensure to set up pinMode(D2, INPUT_PULLUP) and watch for LOW when moisture exceeds threshold.
Applications
Automated plant watering systems
Soil moisture data logging
Garden automation and greenhouse control
Educational electronics and IoT prototypes
Real-time monitoring in agriculture
✅ Resources
📄 Datasheet: FC‑28 Soil Moisture Sensor Module – detailed module specs and probe materials pishop.us+1makerguides.com
🎥 YouTube Tutorial: Arduino soil moisture sensor tutorial with circuit diagrams and working code makerguides.com+6circuitdigest.com+6arduinogetstarted.com+6