This Is A Simple Moisture Sensor That Can Be Used To Detect Soil Moisture. When The Soil Is Short Of Water, The Module Outputs A High Level, Otherwise It Outputs A Low Level. Use This Sensor To Create An Automatic Flower Watering Device So That Needs To Manage The Plants In Your Garden. The Sensitivity Is Adjustable (Adjusted By The Blue Digital Potentiometer In The Picture); The Comparator Uses The Lm393 Chip, Which Works Stably Equipped With Fixing Bolt Holes For Easy Installation Working Voltage 3.3V-5V; Power Indicator Light (Red) And Digital Switch Output Indicator Light (Green) Module Dual Output Mode, Simple Digital Output And More Advanced Analog Outpu<br><br>Small Board Interface Description (4-Wire System) 1. Vcc External 3.3V-5V 2. Gnd External Gnd 3. Do Small Board Digital Output Interface (0 And 1) 4. Ao Small Board Analog Output Interface Instructions For Use: 1. The Soil Moisture Module Is Sensitive To Environmental Humidity And Is Generally Used To Detect Soil Moisture. 2. When The Soil Moisture Does Not Reach The Set Threshold, The Module Outputs A High Level At The Do Port. When The Soil Moisture Exceeds The Set Threshold, The Module D0 Outputs A Low Level; 3. The Digital Output D0 Of The Small Board Can Be Directly Connected To The Microcontroller, And The High And Low Levels Are Detected Through The Microcontroller To Detect Soil Moisture; 4. The Small Digital Output Do Can Directly Drive Our Relay Module, Buzzer Module, Etc., Thus Forming A Soil Moisture Alarm Device; 5. The Small Board Analog Output Ao Can Be Connected To The Ad Module. Through Ad Conversion, The Latest Value Of Soil Moisture Can Be Obtained; Note:Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use Colour:Random Color(Color is random and cannot be specified) Material:ABS+PCB<br><br>Package Contents: 20 * Soil Detection Module 20 * Sensor Module 20 * Wiring Harness Set(Color is random and cannot be specified)<br><br>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.