Make a Soil Moisture Detection Device Using Arduino

Illustration

First, we will declare the following four variables: two for Red and Green, the third is for the analog pin and the last one is for the value that we received from the soil moisture. In the Setup() block, we just declared the OUTPUT pins. I know, we have used two LEDs, so two pinMode() are there. Apart from that, we set the Serial Initializers. Then, in the loop() block, first, we will read the analog value from the analogRead() method. And, we know it returns a three-digit number. So, to put the soil-moisture value on the scale of 10 we divided that value by 100. After putting that value on the Serial, we will decide whether the moisture value is suitable for the plant or not. For that, we first put the probe in water and check what it returns.

Figure 4: Put the probe in water

And, in return, it will show 2 as the moisture value and that is quite low on the scale of 10 (in other words a very high moisture value). As a threshold, we use 5 as the critical value. If the moisture value gets below 5 then it suggests that the soil is moist (in other words has water). On the contrary, if the value gets above 5 then it needs to be watered (in other words a low value of water). How it will look Write the code and upload it to the Arduino. After uploading, open the Serial Monitor to see the moisture data.

Figure 5: Open Serial Monitor

In my case, the pot is too humid so I can't show you a dry soil's value. Still, I have placed that probe outside just to show how it will behave when there is less water or moisture in the pot.

Figure 6: Less water or moisture in the pot

Conclusion

This is a very basic prototype design where we used just one sensor, in other words, Soil Moisture Sensor. Additionally, we can add an LCD screen that constantly shows the moisture value or shows a notification-area that notifies you when it goes low/high.