Soil Moisture Sensor Module YL-69 – Hygrometer Detection for Arduino & Smart Irrigation in Pakistan

Overview

The Soil Moisture Sensor (Hygrometer) is a simple breakout board designed to measure the moisture level in soil and similar materials. The module consists of two parts: the soil probe (the forks) and the electronic control module. It uses the principle of electrical resistance to determine moisture—more water in the soil means better conductivity and a lower resistance. This sensor is the heart of any Smart Agriculture or Automated Irrigation project.

Key Features

• Dual Output Mode:

  • Analog (A0): Provides a precise real-time reading of moisture levels—perfect for tracking soil drying patterns.

  • Digital (D0): Provides a simple HIGH/LOW trigger once the soil reaches a certain dryness (adjustable via potentiometer).

  • Anti-Corrosion Coating: The probe is designed to withstand the harsh environment of damp soil.

  • Plug-and-Play: Includes the probe, the control module, and the jumper wires for an easy out-of-the-box experience.

  • Adjustable Threshold: The onboard blue potentiometer allows you to set the exact “Dry” point to trigger an external pump or buzzer.

Technical Specifications

Feature	Specification
Operating Voltage	3.3V to 5V DC
Output Signal	Analog (Voltage) & Digital (Switch)
Comparator Chip	LM393
Probe Dimensions	60mm x 30mm
Control Board Size	30mm x 16mm
Power Indicator	Red LED
Switch Indicator	Green/Digital Output LED