Description: 1. This is a summary of the moisture sensor 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 need people to manage . 2. adjustable sensitivity ( shown in blue digital potentiometer adjustment ) 3. Operating Voltage 3.3V-5V 4. Module Dual Output mode , a simple digital output , analog output more accurate. 5. with fixed bolt hole for easy installation 6. small PCB board size :3cm * 1.6cm 7. power indicator ( red ) and the digital switch output indicator ( green ) 8. using LM393 comparator chip , stable VCC external 3.3V-5V GND GND External DO small board digital output interfaces ( 0 and 1 ) AO small board analog output interface Instructions:A soil moisture and humidity module most sensitive to the environment , usually used to detect soil moisture . Modules in the soil moisture reach the set threshold , DO port output high when soil moisture exceeds a set threshold, the module D0 output low ; Digital outputs D0 small plates can be directly connected with the microcontroller through the microcontroller to detect high and low , thereby detecting soil moisture; Small plates digital output DO OUR relay module can directly drive the buzzer module , which can be composed of a soil moisture alarm equipment ; 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 ; Package Included:1pcs x Soil Moisture Hygrometer Detection Humidity Sensor Module