#include <LiquidCrystal_I2C.h>
#include <EEPROM.h>
#include <Wire.h>

// Initialize LCD object with address 0x3F, 16 columns, and 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Variables for ultrasonic sensor, water level, set value, and pump state
long duration, inches;
int set_val, percentage;
bool state, pump;

void setup() {
  // Begin serial communication at 9600 bps
  Serial.begin(9600);
  
  // Initialize and turn on the LCD
  lcd.init();
  lcd.backlight();
  
  // Display initial messages on the LCD
  lcd.print("WATER LEVEL:");
  lcd.setCursor(0, 1);
  lcd.print("PUMP:OFF MANUAL");
  
  // Set pin modes for sensors and actuators
  pinMode(2, OUTPUT);           // Trigger pin for ultrasonic sensor
  pinMode(3, INPUT);            // Echo pin for ultrasonic sensor
  pinMode(10, INPUT_PULLUP);    // Button for setting water level manually
  pinMode(11, INPUT_PULLUP);    // Button for manual control of the pump
  pinMode(6, OUTPUT);           // Piezo buzzer control
  pinMode(12, OUTPUT);          // Pump control
  pinMode(7, OUTPUT);           // LED indicator for pump status
  
  // Initialize the set value for water level
  set_val = 25;
}

void loop() {
  // Trigger ultrasonic sensor to measure distance
  digitalWrite(2, HIGH);
  delayMicroseconds(10);
  digitalWrite(2, LOW);
  duration = pulseIn(3, HIGH);
  inches = microsecondsToInches(duration);
  
  // Calculate the water level percentage
  percentage = (set_val - inches) * 110 / set_val;
  
  // Display water level percentage on the LCD
  lcd.setCursor(12, 0);
  if (percentage < 0)
    percentage = 0;
  lcd.print(percentage);
  lcd.print("%   ");

  // Check water level and manual control button for pump activation
  if (percentage < 30 && digitalRead(11)) {
    pump = 1;
    digitalWrite(7, HIGH);  // Turn on pump indicator LED
  }

  // Check water level for pump deactivation
  if (percentage > 85) {
    pump = 0;
    digitalWrite(7, LOW);   // Turn off pump indicator LED
  }

  // Activate buzzer for low water level and manual mode
  if (percentage < 30 && digitalRead(11)) {
    tone(6, 262, 1000);
    delay(3000);
  }

  // Display pump status on the LCD
  lcd.setCursor(5, 1);
  if (pump == 1)
    lcd.print("ON ");
  else if (pump == 0)
    lcd.print("OFF");

  // Display manual or auto mode on the LCD
  lcd.setCursor(9, 1);
  if (!digitalRead(11))
    lcd.print("MANUAL ");
  lcd.print("AUTO   ");

  // Check button states for setting water level manually or toggling pump state
  if (!digitalRead(10) && !state && digitalRead(11)) {
    state = 1;
    set_val = inches;
    EEPROM.write(0, set_val);
  }

  if (!digitalRead(10) && !state && !digitalRead(11)) {
    state = 1;
    pump = !pump;
  }

  if (digitalRead(10))
    state = 0;

  // Delay for stability and update the pump control
  delay(500);
  if (pump == 1 || percentage < 30) {
    digitalWrite(12, HIGH);  // Turn on the pump
  } else {
    digitalWrite(12, LOW);   // Turn off the pump
  }

  // Print the state to Serial for debugging
  Serial.println(state);
}

// Function to convert microseconds to inches
long microsecondsToInches(long microseconds) {
  return microseconds / 29 / 2;
}