Soil Moisture Meter, Soil Humidity Sensor, Water Sensor, Soil Hygrometer for Arduino consists of two probes that measure the volume of water in the soil. The two probes allow the electric current to pass through the soil and, according to its resistance, measures the moisture level of the soil.
When there is more water, the soil conducts more electricity, which means that the resistance will be less. So the moisture level will be higher. Dry soil reduces conductivity. So, when there is less water, the soil conducts less electricity, which means it has more resistance. So the moisture level will be lower.
It has a detection length of 38mm and a working voltage of 2V-5V. It has a Fork-like design, which makes it easy to insert into the soil. The analog output voltage boosts along with the soil moisture level increases.
VCC: 3.3V-5V GND: GND DO: Digital output interface(0 and 1) AO: Analog output interface