Maker Soil Moisture Sensor measures soil moisture by capacitive sensing, where the presence of water in the soil will increase the probe capacitance. The output of the sensor is analog output; higher moisture levels will produce 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. It only needs 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 specifications. Note that 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.
Full Tutorial: Battery Powered Maker Soil Moisture Sensor
Maker Soil Moisture Sensor can also be used with microcontrollers 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.
Full Tutorial: Self Watering Pot Featuring Maker Soil Moisture Sensor
It is important to note that this sensor can only qualitatively test the humidity of the soil and cannot measure quantitatively. Which means when the humidity of the soil rises, the value of the output decreases; conversely, when the humidity decreases, the output value becomes higher.
Operating Voltage: 2.5V - 7.0V.
Output: Analog Voltage (Higher moisture = lower voltage)
LED indicators for dry/moist/wet soil moisture levels.
Soil Limit (Maximum depth of the probe)
Double-sided probe (More sensitive to moisture changes)
Capacitive sensing probe (Corrosion resistant)
Disable pin (Power-saving application)
Soil moisture detection
Automatic Plant Watering System