Soil Moisture Sensor Module

The Soil Moisture Sensor Module (YL-69 with LM393 Comparator) is designed to measure the moisture content of soil by detecting its electrical conductivity. It includes a soil probe, an LM393 comparator control board, and connecting wires, making it ideal for Arduino, ESP32, Raspberry Pi, automatic irrigation systems, smart farming, and IoT projects.

Features

• Full Name: YL-69 Soil Moisture Sensor Module with LM393 Comparator
• Detects soil moisture level accurately
• Adjustable sensitivity using onboard potentiometer
• Provides both Analog (AO) and Digital (DO) outputs
• Low power consumption
• Easy interfacing with microcontrollers
• Onboard power and output indicator LEDs
• Corrosion-resistant probe (for intermittent use)
• Compact and lightweight design
• Ideal for smart irrigation and automation projects

Specifications

Specification	Value
Product Type	Soil Moisture Sensor Module
Sensor Model	YL-69
Comparator IC	LM393
Operating Voltage	3.3V – 5V DC
Operating Current	≤20mA
Output Type	Analog (AO) & Digital (DO)
Detection Method	Soil Conductivity
Adjustable Threshold	Yes (Onboard Potentiometer)
Interface	4-Pin Header

Applications / Uses

• Automatic plant watering systems
• Smart irrigation systems
• Arduino and ESP32 projects
• Raspberry Pi projects
• Smart agriculture
• Greenhouse monitoring
• Garden automation
• Soil moisture monitoring
• IoT farming projects
• Educational electronics
• Home gardening
• DIY automation projects

Pin Configuration

Pin	Function
VCC	3.3V–5V Power Supply
GND	Ground
AO	Analog Output
DO	Digital Output

Working Principle

1. Insert the soil probe into the soil.
2. The probe measures soil conductivity, which changes with moisture content.
3. The control module processes the signal using the LM393 comparator.
4. AO provides a variable analog voltage proportional to soil moisture.
5. DO changes its logic state when the moisture level crosses the threshold set by the potentiometer.

Size

Soil Probe

• Length: Approx. 60 mm
• Width: Approx. 20 mm

Control Module

• Length: Approx. 32 mm
• Width: Approx. 14 mm
• Height: Approx. 12 mm

Jumper Wires

• Length: Approx. 20 cm
• Weight: Approximately 20–25 g (Complete Kit)

Package Includes

• 1 × YL-69 Soil Moisture Sensor Probe
• 1 × LM393 Comparator Module
• 2 × Connecting Jumper Wires

Note: To extend the life of the sensor probe, avoid leaving it continuously powered in wet soil. For long-term installations, power the sensor only when taking readings or consider using a capacitive soil moisture sensor for improved durability.