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

// Pin Assignments
const int potentiometer_pin = A0; // Analog pin for the potentiometer (simulating pH sensor)
const int DHT_pin = 2;            // Digital pin for DHT sensor

// Ultrasonic Sensor Pin Assignments
const int trigPin = 7;            // Trigger pin for the ultrasonic sensor
const int echoPin = 8;            // Echo pin for the ultrasonic sensor

// DHT Sensor settings
#define DHTTYPE DHT11  // Use DHT11 or DHT22
DHT dht(DHT_pin, DHTTYPE);

// Initialize the LCD (RS, E, D4, D5, D6, D7)
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  Serial.begin(9600);
  lcd.begin(16, 2);   // Set up the LCD's number of columns and rows
  dht.begin();        // Initialize the DHT sensor

  // Ultrasonic sensor setup
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Display a startup message in English
  lcd.print("Water Quality");
  lcd.setCursor(0, 1);
  lcd.print("Monitoring");
  delay(2000);  // Wait for 2 seconds
  lcd.clear();  // Clear the LCD
}

void loop() {
  // Read potentiometer value (simulating pH value)
  int potentiometer_value = analogRead(potentiometer_pin);
  float pH = map(potentiometer_value, 0, 1023, 0, 14);  // Simulate pH between 0 and 14

  // Read temperature and humidity from DHT sensor
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Read ultrasonic sensor for water level measurement
  long duration, distance;
  
  // Clear the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Set the trigPin HIGH for 10 microseconds to send a pulse
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Read the echoPin and calculate the time it took for the pulse to return
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate the distance (in cm)
  distance = duration * 0.034 / 2;  // Divide by 2 because the pulse travels to the object and back
  
  // Map distance to water level percentage (adjust max distance according to your tank size)
  int waterLevelPercentage = map(distance, 0, 100, 100, 0);  // Assuming 100 cm is the max height of the water level
  
  // Ensure the value stays between 0% and 100%
  waterLevelPercentage = constrain(waterLevelPercentage, 0, 100);

  // Display values on the LCD
  lcd.setCursor(0, 0);
  lcd.print("pH: ");
  lcd.print(pH);

  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print("C ");

  lcd.setCursor(9, 1);
  lcd.print("Lvl: ");
  lcd.print(waterLevelPercentage);
  lcd.print("%");

  // Print values to Serial Monitor for debugging
  Serial.print("pH: ");
  Serial.print(pH);
  Serial.print(" | Temperature: ");
  Serial.print(temperature);
  Serial.print(" C | Humidity: ");
  Serial.print(humidity);
  Serial.print(" % | Water Level: ");
  Serial.print(waterLevelPercentage);
  Serial.println(" %");

  delay(2000);  // Delay 2 seconds before the next loop
}