HIGH COMPATIBILITY: The product includes an integrated voltage regulator which gives it an operating voltage range of 3.3 to 5.5 V. It is compatible with low voltage microcontrollers (3.3 V and 5 V logic). A miniature PC like the Raspberry Pi only needs an external ADC (analog signal to digital signal) conversion module to operate.LONG LIFESPAN: The principle of capacitive sensing is used to detect soil moisture. It is made of corrosion resistant material. It avoids the problem of being easily corroded and greatly extends its service life.INTUITIVE AND PRACTICAL: It is possible to read the real-time amount of moisture present in the soil (to judge whether the soil is wet or dry) by connecting the analog output (AOUT) of the module to an analog input (A0) of the Arduino. WIDE APPLICATIONS: Thanks to simple design, can automatically water the vegetable garden, garden, control the soil humidity of the flower pot, all electronic competitions and for Arduino Raspberry pi design, etc.ATTENTION: Since this sensor monitors soil moisture according to the principle of capacitive sensing, it is reflected in different places where the soil moisture is different, the tightness is different, and the insertion depth is different. Even in the same place, the same depth is in the second. At the time of the second insertion, the humidity may be reading lower than the first time because the soil came loose during the first extraction.Technical specifications:Operating voltage: 3.3V~5.5VOutput voltage: 0-3V DCInterface: PH2.54-3PPCb interface description: VCC (external 3.3V-5V), GND (external GND), AOUT (analog output) Panel PCB dimension: 98mm x 23mm \/ 3.86\