Keyestudio KS0049 Soil Moisture Sensor Humidity Detection Module for Arduino (BLACK)

Descriptions: 
This is a simple soil humidity sensor aimed to detect the soil humidity.
If you use this sensor to make an automatic watering device, it can detect whether your botany is thirsty to prevent it from withering when you go out.
Using this sensor with Arduino controller can make your plants more comfortable and your garden smarter.

Features: 
- When the sensor is totally immersed in water, the voltage will be 2.3V
- Gold-plated surface for enhancing conductivity and corrosion resistance

Working Principle
If the current goes through the soil, the sensor will get resistance value by reading the current changes between the two probes, then convert the resistance value into moisture content

Parameter:
- Sensor type: analog output
- Power supply voltage: 3.3 - 5V
- Output voltage: 0 - 2.3V
- Working current: 20mA and less
- Service life: about 1 year
- Interface definition: pin1- signal, pin2- GND, pin3 - VCC