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

#define LDR_DIGITAL_PIN 12  // LDR digital pin
#define TRIG_PIN 10 // HC-SR04 TRIG pin
#define ECHO_PIN 11 // HC-SR04 ECHO pin
#define DHTPIN 8 // DHT22 sensor pin
#define PIR_PIN 13 // PIR motion sensor pin

LiquidCrystal lcd(7, 6, 5, 4, 3, 2); // RS, E, D4, D5, D6, D7
DHT dht(DHTPIN, DHT22);

void setup() {
  pinMode(LDR_DIGITAL_PIN, INPUT); // Set LDR digital pin as input
  pinMode(TRIG_PIN, OUTPUT); // Set TRIG pin as output
  pinMode(ECHO_PIN, INPUT);  // Set ECHO pin as input
  pinMode(PIR_PIN, INPUT);   // Set PIR pin as input

  dht.begin();
  
  lcd.begin(16, 2);
  lcd.print("Sensor Test"); // Display initializing message
  delay(2000); // Wait for 2 seconds before clearing the display
  lcd.clear();
}

void loop() {
  displayLDRReading();
  delay(2000); // Display LDR reading for 2 seconds

  displayDistanceReading();
  delay(2000); // Display distance reading for 2 seconds

  displayDHTReading();
  delay(2000); // Display DHT22 reading for 2 seconds

  displayPIRStatus();
  delay(2000); // Display PIR status for 2 seconds
}

void displayLDRReading() {
  int ldrValue = digitalRead(LDR_DIGITAL_PIN); // Read LDR digital value
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("LDR: ");
  if (ldrValue == LOW) {
    lcd.print("Bright");
  } else {
    lcd.print("Dark");
  }
}

void displayDistanceReading() {
  float distance = getDistance(); // Get distance from ultrasonic sensor
  
  lcd.clear();
  lcd.setCursor(0, 1);
  lcd.print("Distance: ");
  lcd.print(distance);
  lcd.print(" cm");
}

void displayDHTReading() {
  float humidity = dht.readHumidity(); // Read humidity from DHT22 sensor
  float temperature = dht.readTemperature(); // Read temperature from DHT22 sensor in Celsius
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print(" C");

  lcd.setCursor(0, 1);
  lcd.print("Humidity: ");
  lcd.print(humidity);
  lcd.print(" %");
}

void displayPIRStatus() {
  int pirState = digitalRead(PIR_PIN); // Read PIR sensor state
  
  lcd.clear();
  lcd.setCursor(0, 0);
  if (pirState == HIGH) {
    lcd.print("PIR Active");
  } else {
    lcd.print("No Motion");
  }
}

float getDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  float duration = pulseIn(ECHO_PIN, HIGH);
  return (duration * 0.0343) / 2.0; // Calculate distance in cm
}