Soil Moisture Sensor Module | Soil Humidity Sensor

The Soil Moisture Sensor Module pairs a 6cm x 3cm fork-shaped soil probe with a 3cm x 1.5cm driver board over a 20cm cable, operating from 3.3V to 5V DC with analog and digital outputs. A key feature of this soil humidity sensor’s driver board is its onboard potentiometer, which lets the digital output (DO) threshold be physically adjusted by turning a small screw — rather than relying purely on software thresholds, the sensitivity at which the moisture detection sensor triggers wet/dry can be tuned directly on the hardware.

The soil moisture detector’s analog output bypasses this threshold entirely, giving a raw continuous voltage reading proportional to soil conductivity that can be mapped in Arduino code to a moisture percentage through simple calibration — placing the probe in dry air and then in water gives the two reference points needed. As a soil sensor used in soil moisture sensor arduino projects, most makers prefer the analog pin for graduated readings and reserve the digital pin for simple standalone alarm circuits that don’t need a microcontroller at all.

the soil moisture sensor price reflects a sensor whose AO readings drift with probe corrosion over weeks of soil contact, so periodic recalibration improves long-term accuracy on this basic resistive design. This StemVolt module is well-suited for engineers building calibrated soil monitoring systems and practical plant care automation electronics projects.