This is a simple moisture sensor that can be used to detect soil moisture. When the soil lacks water, the sensor output value decrease, and vice increase. Use this sensor to create an automatic watering device that eliminates the need for human management of plants in your garden. The sensor has been gold-plated, which can extend its service life. Insert it into the soil and then use an AD converter to read it. With his help, the plant remind you: Hey, I'm thirsty, please give me some water. Technical specifications: Supply voltage: 3.3V or 5V Interface definition: 1-pin signal, 2-pin ground, 3-pin positive power supply Output signal type: Analog signal (0-2.3V [2.3V is the voltage value completely immersed in water], 5V power supply), the higher the humidity, the higher the output voltage. Note:Installation guide not included, Please check as much as possible to make sure the item is what you need. Color:As Shown Material:PCB Package Contents: 1 * Soil Moisture Sensor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.