If you want to detect the level of moisture in the soil or to recognize when you need to water your plants easily, you will make use of the moisture sensor. The device is also helpful for carrying out experiments in environmental science, soil science, biology, horticulture, agricultural science, and botany.
The moisture sensor measures the amount of water in the soil by following the capacitance to measure the volumetric content of water. It also helps users to understand climatic conditions as they change. Also, the moisture sensor helps to protect important water resources.
A soil moisture sensor is very easy to use. All you will do is insert the sensor into the target soil, and it will show you the data in percentages. There are other ways you can check the moisture with the sensor.
To use the Arduino, insert the moisture sensor into your target soil. When you have done this, plug it to your Arduino Seeduino, connect the Arduino to a PC using your USB cable and read the soil data.
Hooking up your moisture sensor is very simple. There are just three pins which you have to connect: GND, SIG, and VCC. You have to power the GND and VCC while the SIG's analog signal that you will join an ADC pins on your choice microcontroller. It is important to note that the voltage powering the moisture sensor also affect the value which the SIG will show.
If you are going to use your sensor outside, make sure to protect the PCB so that it can last longer. You can use hot glue or cover the solder and the critical SMD parts on your PCB with conformal coating. However, hot glue and sun don't match unless the project will not expose the sensor to very high temperatures.