Description: Can be used to detect the moisture of the soil, when the soil is dry , the module outputs a high level , whereas the output low. Using this sensor make an automatic watering system , so that your garden plants NOT need people to manage . Adjustable sensitivity ( shown in blue digital potentiometer adjustment ) Operating Voltage 3.3V-5V Module Dual Output mode, a simple digital output, analog output more accurate. Specification: With Solid Bolt Hole for Easy Installation Small Circuit Board Size: 3x1.6cm/1.18x0.63in Power indicator: Red Digital switch output indicator: Green With LM393 comparator chip, stable. VCC External: 3.3v-5v GND External DO small board digital output interfaces (0 and 1) AO small board analog output interface Package Includes: 1X Soil Moisture Sensor Note: Instructions for use: 1.A soil moisture and moisture modulus most sensitive to the environment, usually used to detect soil moisture. 2.Modules in the soil moisture reach the set threshold, TUN port output high, when soil moisture reaches a set threshold, the module D0 output low; 3.Digital outputs D0 small plates can be directly connected to the microcontroller through the microcontroller detect high and low, reducing soil moisture; 4.Small plates digital output DO OUR relay module can directly drive the buzzer module, which can get out of a soil moisture alarm equipment; 5.Small plates AO analog output modules can be connected and AD through the AD converter, you can get a more accurate value of soil moisture.