DollaTek 12V Digital Soil Humidity Sensor Controller (XH-M214) Instruction Manual

Introduction

This DollaTek 12V Digital Soil Humidity Sensor Controller, model XH-M214, is designed for automatic irrigation systems in home gardening, agriculture monitoring, and other control applications. The soil probe directly measures soil moisture, displaying the value on a digital screen. The system automatically initiates irrigation when soil humidity drops below a user-defined threshold and ceases when it reaches the desired level. This module provides a reliable solution for digital irrigation control.

Image: The DollaTek 12V Digital Soil Humidity Sensor Controller module connected to its soil moisture probe.

Setup

1. Connect the Soil Humidity Sensor: Connect the provided soil humidity sensor probe to the 2-pin connector on the controller module. Ensure a secure connection.
2. Connect Power Supply: Connect a 12V DC power supply to the '12V+' and 'GND' screw terminals on the module. Observe correct polarity.
3. Connect Irrigation Device: Connect your irrigation device (e.g., water pump, solenoid valve) to the relay output terminals. The relay is a normally open (NO) type, meaning the circuit is open when inactive. When activated, the relay closes, completing the circuit to power your irrigation device.
4. Probe Placement: Insert the soil humidity sensor probe directly into the soil at the desired monitoring location.

Image: Connection diagram illustrating how to connect the 12V DC power supply, soil sensor, and a 12V solenoid valve to the controller module.

Operating Instructions

The controller features a 2-digit LED display and three buttons: 'SET', '+', and '-'. The display shows the current soil humidity percentage.

Setting Parameters:

1. F0: Set Start Humidity (Irrigation Activation Threshold)
   • Short press the "SET" button. The display will show "F0".
   • Short press "SET" again. The display will show the current F0 humidity value.
   • Use the "+" or "-" buttons to adjust the desired humidity percentage at which irrigation should begin (relay closes).
2. F1: Set Stop Humidity (Irrigation Deactivation Threshold)
   • Short press the "SET" button to display "F0".
   • Use the "+" or "-" buttons to navigate to "F1".
   • Short press "SET" to display the current F1 humidity value.
   • Use the "+" or "-" buttons to adjust the desired humidity percentage at which irrigation should stop (relay opens).
3. F2: Humidity Correction (Offset)
   • Short press the "SET" button to display "F0".
   • Use the "+" or "-" buttons to navigate to "F2".
   • Short press "SET" to display the current F2 offset value.
   • Use the "+" or "-" buttons to adjust the offset value (range: -15 to +15). This can be used to calibrate the sensor readings.

Important Note:

By default, the values are set to F0: 30% and F1: 70%. Please be aware that settings (F0, F1) may revert to these default values if the power supply to the module is interrupted. If this occurs, you will need to reconfigure your desired settings.

The relay is a normally open type. In the absence of power, the relay circuit is open, and any connected irrigation device will not operate.

Maintenance

• Sensor Probe Inspection: Regularly inspect the soil humidity sensor probe for signs of oxidation or corrosion. Over time, the metal electrodes can degrade, leading to inaccurate readings.
• Cleaning: If oxidation is observed, gently clean the sensor probe electrodes with a fine abrasive or a soft cloth to restore conductivity.
• Replacement: If the sensor probe consistently provides false or unstable readings despite cleaning, consider replacing it to ensure accurate soil moisture monitoring.

Troubleshooting

• Inaccurate or Unstable Readings:
  • Check the soil humidity sensor probe for oxidation or dirt. Clean or replace the probe if necessary.
  • Ensure the probe is fully inserted into the soil and making good contact.
  • Verify the F2 (Humidity Correction) setting is appropriate.
• Settings Not Saving After Power Cycle:
  • This module may not retain settings without continuous power. Re-enter your F0 and F1 values after any power interruption.
• Irrigation Device Not Activating/Deactivating:
  • Verify all power connections (12V DC) to the module are secure and correctly polarized.
  • Check the wiring of your irrigation device to the relay terminals. Ensure it is correctly connected to the normally open (NO) contacts.
  • Confirm that the F0 and F1 humidity thresholds are set correctly and that the current soil humidity is within the activation/deactivation range.
  • Ensure the irrigation device itself is functional.

Specifications

Image: Detailed dimensions of the controller board and the soil humidity sensor probe.

Support

For any questions or further assistance regarding your DollaTek 12V Digital Soil Humidity Sensor Controller, please contact DollaTek customer support via email.