DFRobot Gravity: Analogue Capacitive Soil Moisture Sensor- Corrosion Resistant

This product measures soil moisture levels by capacitive sensing, rather than resistive sensing like other types of moisture sensor. It is made of a corrosion-resistant material giving it long service life. Insert it into the soil and impress your friends with the real-time soil moisture data!
The product includes an on-board voltage regulator which gives it an operating voltage range of 3.3 ∼ 5.5V. It is compatible with low-voltage MCUs (both 3.3V and 5V logic). To make it compatible with a Raspberry Pi, an ADC converter is required.
This sensor is compatible with our 3-pin "Gravity" interface, which means it can be directly connected to the Gravity I/O Expansion Shield.