#include <Servo.h>

// Pin Definitions
#define ULTRASONIC_TRIG 3
#define ULTRASONIC_ECHO 4
#define GAS_SENSOR A1
#define RAIN_SENSOR A2
#define SOUND_SENSOR A3
#define RED_LED 5
#define YELLOW_LED 6
#define GREEN_LED 7
#define SERVO_PIN 9
#define BUZZER 8
#define DC_MOTOR 10

// Constants
#define SOUND_THRESHOLD 500
#define GAS_THRESHOLD 600
#define RAIN_THRESHOLD 500

// Objects
Servo myServo;

void setup() {
  // Initialize components
  pinMode(RED_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(DC_MOTOR, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  
  Serial.begin(9600);
  myServo.attach(SERVO_PIN);
}

void loop() {
  // Scenario 1: Ultrasonic Sensor - Trigger Red LED
  int distance = measureDistance();
  if (distance < 10) {
    digitalWrite(RED_LED, HIGH);
  } else {
    digitalWrite(RED_LED, LOW);
  }

  // Scenario 2: Gas Sensor - Trigger Green LED
  int gasLevel = analogRead(GAS_SENSOR);
  if (gasLevel > GAS_THRESHOLD) {
    digitalWrite(GREEN_LED, HIGH);
  } else {
    digitalWrite(GREEN_LED, LOW);
  }

  // Scenario 3: Rain Sensor - Control Servo
  int rainLevel = analogRead(RAIN_SENSOR);
  if (rainLevel > RAIN_THRESHOLD) {
    myServo.write(90); // Simulate rain action (servo moves)
    digitalWrite(YELLOW_LED, HIGH); // Turn on Yellow LED during rain
  } else {
    myServo.write(0); // No rain, keep servo closed
    digitalWrite(YELLOW_LED, LOW); // Turn off Yellow LED
  }

  // Scenario 4: Sound Sensor - Trigger Green LED
  int soundLevel = analogRead(SOUND_SENSOR);
  if (soundLevel > SOUND_THRESHOLD) {
    digitalWrite(GREEN_LED, HIGH); // Sound detected, turn on Green LED
    tone(BUZZER, 1000); // Buzzer for sound detection
  } else {
    digitalWrite(GREEN_LED, LOW); // No sound, turn off Green LED
    noTone(BUZZER); // Stop buzzer
  }

  // Scenario 5: Control DC Motor
  if (digitalRead(SOUND_SENSOR) == HIGH) {
    digitalWrite(DC_MOTOR, HIGH); // Turn on DC motor when sound detected
  } else {
    digitalWrite(DC_MOTOR, LOW); // Turn off DC motor when no sound
  }

  delay(500); // Delay to avoid rapid changes
}

// Function to measure distance using Ultrasonic Sensor
int measureDistance() {
  digitalWrite(ULTRASONIC_TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(ULTRASONIC_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(ULTRASONIC_TRIG, LOW);
  int duration = pulseIn(ULTRASONIC_ECHO, HIGH);
  return duration * 0.034 / 2; // Convert to cm
}