User Guide: Soil Humidity Moisture Detection Sensor Module with LM393

Introduction:

The Soil Humidity Moisture Detection Sensor Module with LM393 comparator is designed to measure soil moisture levels, providing both digital and analog outputs for versatile applications. This guide offers detailed instructions for setting up and using the sensor effectively, particularly related to: Soil Humidity Moisture Detection Sensor Module and Probe – LM393 aswell relevant to: Automatic Irrigation Kit with Soil Moisture Sensor and Water Pump – DIY.

Components Included:

• Soil Moisture Sensor Probe
• Sensor Module featuring the LM393 comparator
• Connecting Jumper Wires

Specifications:

• Operating Voltage: 3.3V to 5V DC
• Output Types:
  • Digital Output (DO): 0V to 5V, with adjustable threshold via onboard potentiometer
  • Analog Output (AO): 0V to 5V proportional to soil moisture level
• Indicators: Power LED (red) and Digital Output Status LED (green)
• Dimensions: Module: 3.2cm x 1.4cm; Probe Length: approximately 6cm

Features:

• Dual output modes: digital and analog for flexible interfacing
• Adjustable sensitivity using the onboard potentiometer
• LED indicators for power status and digital output
• Compatible with microcontrollers such as Arduino and Raspberry Pi
• Ideal for automated irrigation systems and horticultural applications

Setup Instructions:

1. Connecting the Sensor:

   • Attach the two soil moisture sensor probes to the designated terminals on the sensor module. The orientation of these connections is not polarity-sensitive.
   • Use the provided jumper wires to connect the Sensor Module to your microcontroller or monitoring system as follows:
     • VCC Pin: Connect to your microcontroller’s 3.3V or 5V power supply.
     • GND Pin: Connect to the ground (GND) of your microcontroller.
     • DO (Digital Output) Pin: Connect to a digital input pin on your microcontroller if you intend to use the digital output.
     • AO (Analog Output) Pin: Connect to an analog input pin on your microcontroller if you intend to use the analog output.

2. Adjusting Sensitivity:

   • Use the blue potentiometer for sensitivity adjustment.
   • Clockwise Rotation: Increases the threshold, making the sensor less sensitive to moisture (requires drier conditions to trigger a low digital output).
   • Counterclockwise Rotation: Decreases the threshold, making the sensor more sensitive to moisture (triggers a low digital output at higher moisture levels).

3. Interpreting Outputs:

   • Digital Output (DO):
     • When soil moisture is below the set threshold (soil is dry), the DO pin outputs a high level (5V), and the status LED turns off.
     • When soil moisture exceeds the threshold (soil is wet), the DO pin outputs a low level (0V), and the status LED lights up.
   • Analog Output (AO): Provides a continuous voltage signal proportional to the soil moisture level, allowing for precise monitoring.

Application Example:

To create an automated watering system using an Arduino:

1. Wiring:
   • Connect the sensor module’s VCC and GND pins to the Arduino’s 5V and GND pins, respectively.
   • Connect the DO pin of the Sensor Module to a digital input pin (e.g., D2) on the Arduino.
   • Optionally, connect the AO pin to an analog input pin (e.g., A0) for detailed moisture readings.
2. Programming:
   • Write a program that reads the digital input from the DO pin.
   • If the input indicates dry soil (high level), activate a relay to start a water pump.
   • Once the soil moisture level is adequate (DO pin goes low), deactivate the relay to stop the pump.

Important Considerations:

• Corrosion Prevention: The sensor probes are susceptible to corrosion over time, especially with prolonged exposure to moisture. Use the sensor for intermittent measurements rather than continuous monitoring to extend its lifespan.
• Power Supply: To prevent damage, ensure the module operates within the specified voltage range (3.3V to 5V DC).
• Calibration: Adjust the potentiometer to set the desired moisture threshold based on your specific soil and plant requirements.

Following these instructions, you can effectively integrate the Soil Humidity Moisture Detection Sensor Module with LM393 into your projects. This will enable precise soil moisture monitoring and automated irrigation control.