Disclaimer:
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 )
 
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