Introduction
In this blog, I am going to explain how to develop a soil moisture detecting device using an UNO microcontroller board and a soil moisture sensor. This device can measure real-time soil moisture levels. These devices are mostly used in fields for agriculture farms, construction, cotton spinning industries, etc.... It helps to monitor the real-time moisture level of soil, implement an auto irrigation system in agriculture areas and auto cotton moisture level during the spinning process.
The following prerequisites are required for implementation:
  1. Arduino UNO or Mega
  2. Soil moisture sensor
  3. LCD crystal display [16 X 2 ]
  4. Breadboard
  5. 10K Potentiometer
  6. 220 Ohm resistor
  7. Connecting wires

Step by step implementation of the soil moisture device

Connection diagram
How To Simply Make A Soil Moisture Device Using Arduino
Step 1
In the first step connect a soil electrode and sensor control unit using the positive and negative terminal. This control unit contains 4 terminals on the bottom side.
(+) --> Positive terminal
(-) --> Negative terminal
(AO) --> Analog signal output
(DO) --> Digital signal output
Next, make a connection between the sensor control unit and Arduino as above the connection diagram
Sensor control unit Arduino
(+) -------------------------------> 5V
(-) -------------------------------> GND
AO --------------------------------> A0
Now that the soil moisture sensor has been successfully connected to Arduino, the next step is to connect the LCD crystal to an Arduino UNO Board.
Step 2
Fix the LCD crystal display in the breadboard for easy installation setup. Before installation, refer to the below LCD crystal pin diagram
How To Simply Make A Soil Moisture Device Using Arduino
Place a 10K ohm potentiometer near LCD crystal display. It can adjust the contrast of the LCD screen and create a power connection from Arduino +5V and the GND right and left end of the potentiometer. Make a connection from the center terminal of the potentiometer to VEE (contrast control) LCD crystal display. (Refer to the connection diagram)
Place an 220-ohm resistor in the breadboard and make a connection to (LCD crystal LED +5V Pin)
Step 3
To start a connection with Arduino to LCD crystal display:
PinConfiguration
Arduino BreadBoard LCD Crystal Display
Pin 2 ---------------------------------------------------------------------------> Data pin 7
Pin 3 ---------------------------------------------------------------------------> Data pin 6
Pin 4 ---------------------------------------------------------------------------> Data pin 5
Pin 5 ----------------------------------------------------------------------------> Data pin 4
Pin 11 ----------------------------------------------------------------------------> Register select
Pin 12 ----------------------------------------------------------------------------> Enable
+ 5V -----------------> Potentiometer Center Terminal--------> VEE(Contrast Control)LCD crystal
+5V ---------------------------> 220 ohm Resistor --------------------> LED +5V pin [LCD Crystal]
GND -------------------------------------------------------------------------------> Ground pin & LED - Ground pin [Connect to both pin]
All Connections are perfectly done :)
Let's start with the code:
Step 3
In this step, write code for Arduino using the Arduino IDE.
  1. Download Arduino software using this link here.
  2. Install and open an Arduino IDE in your PC/Laptop
  3. Connect your Arduino board to your computer using a USB data cable
  4. Copy and paste below the code into the Arduino IDE
  1. #include <LiquidCrystal.h>
  2. LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
  4. int sensorPin = A0;
  5. int sensorValue = 0;
  6. int percentValue = 0;
  8. void setup() {
  9. Serial.begin(9600);
  10. lcd.begin(16, 2);
  11. }
  13. void loop() {
  14. sensorValue = analogRead(sensorPin);
  15. Serial.print("\n\nAnalog Value: ");
  16. Serial.print(sensorValue);
  17. percentValue = map(sensorValue, 1023, 200, 0, 100);
  18. Serial.print("\nPercentValue: ");
  19. Serial.print(percentValue);
  20. Serial.print("%");
  21. lcd.setCursor(0, 0);
  22. lcd.print("Soil Moisture");
  23. lcd.setCursor(0, 1);
  24. lcd.print("Percent: ");
  25. lcd.print(percentValue);
  26. lcd.print("%");
  27. delay(1000);
  28. lcd.clear();
  29. }
Save and upload this sketch to the Arduino microcontroller board.
After the sketch upload is completed, the soil moisture detecting device should start working

Output

How To Simply Make A Soil Moisture Device Using Arduino
Here is one of the soil moisture detecting devices working perfectly on farmland.