Planning for an agricultural project - this is the product that you need. Easy to connect with Arduino Raspberry Pi

The soil moisture sensor is pretty straight forward to use. The two large exposed pads function as probes for the sensor, together acting as a variable resistor. The more water that is in the soil means the better the conductivity between the pads will be and will result in a lower resistance, and a higher SIG out

Specifications:-
Operating voltage: 3.3V~5V
Dual output mode,analog output more accurate
A fixed bolt hole for easy installation
With power indicator (red) and digital switching output indicator (green)
Having LM393 comparator chip, stable
Panel PCB Dimension: Approx.3cm x 1.5cm
Soil Probe Dimension: Approx. 6cm x 3cm
Cable Length: Approx.21cm
VCC: 3.3V-5V
GND: GND
DO: digital output interface(0 and 1)
AO: analog output interface

Connections:-
VCC  connect to 3.3V-5V
GND  connect to GND
DO   digital value output connector（0 or 1）
AO  analog value output connector