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

// Define pins for the sensors
#define DHTPIN 4    // DHT22 data pin
#define TRIG_PIN 5  // HC-SR04 trigger pin
#define ECHO_PIN 18 // HC-SR04 echo pin

// Define analog pins for the simulated NPK sensor
#define N_PIN 34 // Analog pin for Nitrogen
#define P_PIN 35 // Analog pin for Phosphorus
#define K_PIN 36 // Analog pin for Potassium

// Uncomment the type of sensor in use:
//#define DHTTYPE DHT11   // DHT 11
#define DHTTYPE DHT22 // DHT 22 (AM2302)

// Initialize DHT sensor.
DHT dht(DHTPIN, DHTTYPE);

// Speed of sound in cm/us
#define SOUND_SPEED 0.034

// Initialize LCD displays (change I2C addresses if different)
LiquidCrystal_I2C lcdDHT(0x27, 16, 2);       // Address 0x27 for DHT22 display
LiquidCrystal_I2C lcdUltrasonic(0x3F, 16, 2); // Address 0x3F for Ultrasonic display
LiquidCrystal_I2C lcdNPK(0x3E, 16, 2);       // Address 0x3E for NPK display

void setup() {
  // Start the Serial Monitor
  Serial.begin(115200);
  Serial.println(F("DHT22, Ultrasonic, and NPK sensor test!"));

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

  // Initialize the ultrasonic sensor pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  // Initialize each LCD display
  lcdDHT.init();
  lcdDHT.backlight();

  lcdUltrasonic.init();
  lcdUltrasonic.backlight();

  lcdNPK.init();
  lcdNPK.backlight();

  // Print initial messages on LCDs
  lcdDHT.setCursor(0, 0);
  lcdDHT.print("DHT22: ");
  
  lcdUltrasonic.setCursor(0, 0);
  lcdUltrasonic.print("Ultrasonic: ");
  
  lcdNPK.setCursor(0, 0);
  lcdNPK.print("NPK: ");

  Serial.println("Setup completed");
  delay(1000); // Allow some time for the sensors to initialize
}

void loop() {
  // Wait a few seconds between measurements.
  delay(2000);

  // Reading temperature and humidity from DHT22
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Check if any reads failed
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println(F("Failed to read from DHT sensor!"));
    lcdDHT.setCursor(7, 1);
    lcdDHT.print("Error");
  } else {
    // Print DHT sensor results
    Serial.print(F("Humidity: "));
    Serial.print(humidity);
    Serial.print(F("%  Temperature: "));
    Serial.print(temperature);
    Serial.println(F("°C"));

    // Display on LCD
    lcdDHT.setCursor(7, 1);
    lcdDHT.print(temperature, 1);
    lcdDHT.print(" C");
    
    // Check conditions
    if (temperature > 38) {
      Serial.println(F("High temperature! Highly drought."));
    } else {
      Serial.println(F("Normal weather."));
    }

    if (humidity < 35) {
      Serial.println(F("Alert: Watering is required!"));
    }
  }

  // Send a short pulse to trigger the ultrasonic sensor measurement
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Read the echo duration
  long duration = pulseIn(ECHO_PIN, HIGH, 60000); // Timeout in 60ms

  // Calculate distance in cm
  float distance = (duration * SOUND_SPEED) / 2;

  // Print distance
  if (duration == 0) {
    Serial.println(F("No echo received or out of range"));
    lcdUltrasonic.setCursor(11, 1);
    lcdUltrasonic.print("Error");
  } else {
    if (distance > 400 || distance < 2) { // Assuming sensor range 2cm to 400cm
      Serial.println("Distance out of range");
      lcdUltrasonic.setCursor(11, 1);
      lcdUltrasonic.print("Out of Range");
    } else {
      Serial.print(F("Distance: "));
      Serial.print(distance);
      Serial.println(F(" cm"));

      // Display on LCD
      lcdUltrasonic.setCursor(11, 1);
      lcdUltrasonic.print(distance);
      lcdUltrasonic.print(" cm");
    }
  }

  // Read simulated NPK values
  int nitrogen = analogRead(N_PIN);
  int phosphorus = analogRead(P_PIN);
  int potassium = analogRead(K_PIN);

  // Print NPK sensor results
  Serial.print(F("Nitrogen (N): "));
  Serial.println(nitrogen);

  Serial.print(F("Phosphorus (P): "));
  Serial.println(phosphorus);

  Serial.print(F("Potassium (K): "));
  Serial.println(potassium);

  // Display on LCD
  lcdNPK.setCursor(8, 0);
  lcdNPK.print(nitrogen);
  lcdNPK.setCursor(8, 1);
  lcdNPK.print(phosphorus);
  lcdNPK.setCursor(8, 2);
  lcdNPK.print(potassium);

  delay(1000); // Wait for a second before the next measurement
}