his is a simple water sensor that can be used to detect soil moisture when the soil moisture deficit module plant waterer device, so that the plants in your garden without people to manage. It gives a digital output of 5V when the moisture level is high and 0V when the moisture level is low in the soil.

Test Procedure:

First, we use 5v voltage to the  Soil moisture sensor on pin VCC and GND，the green Power Indicator will be turned on, then we plug it into a small cup, which already filled with dry soil, and then we pour some water into it，you will find the red led light is on now, if it changes back to dry, it will off. Meanwhile,   and if you test the voltage on the pin of DO,  it will change from 4.5v to about 0.15volt, so it is working now, even you can use it to make automatic equipment to water your flower.