#include <EEPROM.h>
#include <LiquidCrystal.h>
#include <DHT.h>

// Initialize the LCD with the appropriate pins
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

// Define the DHT22 sensor pin and type
#define DHTPIN 13
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

long duration, inches;
int set_val, percentage;
bool state, pump;

void setup() {
  // Initialize the LCD with 16 columns and 2 rows
  lcd.begin(16, 2);
  lcd.print("WATER LEVEL:");
  lcd.setCursor(0, 1);
  lcd.print("PUMP:OFF MANUAL");

  // Configure pin modes
  pinMode(8, OUTPUT);       // Ultrasonic trigger pin
  pinMode(9, INPUT);        // Ultrasonic echo pin
  pinMode(10, INPUT_PULLUP);// Set button pin
  pinMode(11, INPUT_PULLUP);// Mode switch pin
  pinMode(12, OUTPUT);      // Pump control pin

  // Initialize the DHT sensor
  dht.begin();

  // Read the set value from EEPROM, max it to 150 if it exceeds
  set_val = EEPROM.read(0);
  if (set_val > 150) set_val = 150;
}

void loop() {
  // Trigger the ultrasonic sensor
  digitalWrite(8, LOW);
  delayMicroseconds(2);
  digitalWrite(8, HIGH);
  delayMicroseconds(10);
  digitalWrite(8, LOW);
  duration = pulseIn(9, HIGH);

  // Convert the duration to inches
  inches = microsecondsToInches(duration);

  // Calculate the percentage of water level
  percentage = (set_val - inches) * 100 / set_val;
  if (percentage < 0) percentage = 0;

  // Update the LCD with the water level percentage
  lcd.setCursor(12, 0);
  lcd.print(percentage);
  lcd.print("%   ");

  // Control the pump based on water level and mode
  if (percentage < 30 && digitalRead(11)) pump = 1;
  if (percentage > 99) pump = 0;
  digitalWrite(12, !pump);

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

  // Update the LCD with the mode status
  lcd.setCursor(9, 1);
  if (!digitalRead(11)) lcd.print("MANUAL");
  else lcd.print("AUTO   ");

  // Set the water level value when button is pressed in auto mode
  if (!digitalRead(10) && !state && digitalRead(11)) {
    state = 1;
    set_val = inches;
    EEPROM.write(0, set_val);
  }

  // Toggle the pump when button is pressed in manual mode
  if (!digitalRead(10) && !state && !digitalRead(11)) {
    state = 1;
    pump = !pump;
  }

  // Reset the state when the button is released
  if (digitalRead(10)) state = 0;

  // Read temperature and humidity from DHT22
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t)) {
    lcd.setCursor(0, 0);
    lcd.print("DHT22 ERROR   ");
    return;
  }

  // Display temperature and humidity on the LCD
  lcd.setCursor(0, 0);
  lcd.print("Temp:");
  lcd.print(t);
  lcd.print("C");

  lcd.setCursor(0, 1);
  lcd.print("Hum:");
  lcd.print(h);
  lcd.print("%");

  delay(500); // Wait for 500 milliseconds before next loop iteration
}

// Convert microseconds to inches
long microsecondsToInches(long microseconds) {
  return microseconds / 74 / 2;
}