The Maker Soil Moisture Sensor measures soil moisture using capacitive sensing, where the presence of water in the soil will increase the probe’s capacitance. The output of the sensor is analog – higher moisture levels will produce a lower output voltage. Being part of the Maker Series, the sensor is equipped with many features to further simplify digital making for beginners and experts alike.

The Maker Soil Moisture Sensor is easy to use. In the minimal setup, it only requires a power supply (if the LED indicators alone are enough for your application). Make sure that the voltage level of the power supply is within the sensor’s specifications (2.5-7VDC). The LED indicators only indicate approximate moisture levels and might fluctuate depending on the power supply, since the sensor does not have a voltage regulator on board.

The Maker Soil Moisture Sensor can also be used with microcontrollers (such as the Maker Pi RP2040) to build more complex projects like smart gardens and self-watering systems. The analog output voltage of the sensor is used for these applications. Furthermore, the sensor also has a disable pin for power saving applications. Sending HIGH signal to the disable pin will disable the sensor.

It is important to note that this sensor can only qualitatively test the humidity of the soil and cannot measure quantitatively. This means when the humidity of the soil rises, the value of the output decreases; conversely, when the humidity decreases, the output value becomes higher.

Got a 3D printer? Check out the printable enclosure on Thingiverse for mounting a 3xAAA battery holder directly to the sensor (this will look great with our Stone Effect PLA filament!).

Features

• Operating Voltage: 2.5V – 7.0V
• Output: Analog Voltage (Higher moisture = lower voltage)
• Grove port
• LED indicators for dry/moist/wet soil moisture levels.
• Soil Limit marker (Maximum depth of the probe)
• Double-sided probe (More sensitive to moisture changes)
• Capacitive sensing probe (Corrosion-resistant)
• Disable pin (Power-saving application)

Example Applications

• Soil moisture detection
• Automatic Plant Watering System
• Smart/IoT Gardens

Package Contents

• 1x Maker Soil Moisture Sensor
• 1x 50cm Grove to Grove cable

3D printed parts, battery holder and Maker Pi RP2040 not included

Resources

• Datasheet
• 3D CAD
• Self-watering pot project (uses 3D printed parts)