Circuit Documentation

Summary

The circuit in question is designed to monitor soil moisture using a Humidity YL-69 sensor and control a 5V mini water pump based on the moisture level. An Arduino UNO serves as the central microcontroller, interfacing with the sensor and an LCD I2C display to provide real-time feedback on the system status and soil moisture level. A relay module is used to control the power to the water pump, and a 12V battery provides the power supply for the system.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Used for reading sensor data, controlling the relay, and updating the display

Humidity YL-69

• Soil moisture sensor
• Provides analog output corresponding to the moisture level in the soil

LCD I2C Display

• Alphanumeric liquid crystal display with I2C communication interface
• Displays system status and soil moisture readings

Battery 12V

• Power source for the circuit
• Provides 12V to power the Arduino UNO through its Vin pin

Relay Module 5V-30V

• Electromechanical switch controlled by the Arduino
• Used to turn the water pump on and off

5V Mini Water Pump

• Small pump for water circulation
• Activated by the relay when the soil moisture is below a certain threshold

Wiring Details

Arduino UNO

• 5V connected to Humidity YL-69 VCC, Relay Module V+, and LCD I2C Display VCC
• GND connected to Humidity YL-69 GND, Relay Module V-, and LCD I2C Display GND
• Vin connected to the positive terminal of the 12V battery
• A0 connected to Humidity YL-69 A0 for analog moisture readings
• A4 (SDA) connected to LCD I2C Display SDA for I2C data
• A5 (SCL) connected to LCD I2C Display SCL for I2C clock
• D2 connected to Relay Module trigger for controlling the relay

Humidity YL-69

• VCC connected to Arduino UNO 5V
• GND connected to Arduino UNO GND
• A0 connected to Arduino UNO A0

LCD I2C Display

• VCC connected to Arduino UNO 5V
• GND connected to Arduino UNO GND
• SDA connected to Arduino UNO A4 (SDA)
• SCL connected to Arduino UNO A5 (SCL)

Battery 12V

• + connected to Arduino UNO Vin
• - connected to Arduino UNO GND

Relay Module 5V-30V

• V+ connected to Arduino UNO 5V
• V- connected to Arduino UNO GND
• common contact connected to the positive terminal of the 12V battery
• normally open connected to the positive pin of the 5V mini water pump
• trigger connected to Arduino UNO D2

5V Mini Water Pump

• positive pin connected to Relay Module normally open
• negative pin connected to the negative terminal of the 12V battery

Documented Code

Arduino UNO Code

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.clear();
  pinMode(2, OUTPUT);
  digitalWrite(2, HIGH);
  delay(1000);
  lcd.setCursor(0, 0);
  lcd.print("Rithunand's");
  lcd.setCursor(0, 1);
  lcd.print("SYSTEM IS ON ");
  lcd.print("");
  delay(3000);
  lcd.clear();
}

void loop() {
  int value = analogRead(A0);
  Serial.println(value);
  if (value > 950) {
    digitalWrite(2, LOW);
    lcd.setCursor(0, 0);
    lcd.print("Water Pump is ON ");
  } else {
    digitalWrite(2, HIGH);
    lcd.setCursor(0, 0);
    lcd.print("Water Pump is OFF");
  }

  if (value < 300) {
    lcd.setCursor(0, 1);
    lcd.print("Moisture : HIGH");
  } else if (value > 300 && value < 950) {
    lcd.setCursor(0, 1);
    lcd.print("Moisture : MID ");
  } else if (value > 950) {
    lcd.setCursor(0, 1);
    lcd.print("Moisture : LOW ");
  }
}

This code initializes the LCD display and sets up the Arduino to read the moisture level from the Humidity YL-69 sensor. Depending on the moisture level, it controls the relay to turn the water pump on or off and updates the display with the system status and moisture level.