The soil moisture sensor consists of two probes which are used to measure the volumetric content of water. The two probes allow the current to pass through the soil and then it gets the resistance value to measure the moisture value.
Wiring Connection:
VCC: 3.3V-5V
GND: GND
DO: Digital output interface(0 and 1)
AO: Analog output interface
Features :
1. Dual output mode, analog output more accurate
2. A fixed bolt hole for easy installation
3. With power indicator (red) and digital switching output indicator (green)
4. Having LM393 comparator chip, stable.