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

// LCD Initialization: Adjust the address if needed
LiquidCrystal_I2C lcd(0x27, 16, 2);

const int sensorPin = A0;       // Potentiometer simulating radiation sensor
const int greenLEDPin = 3;      // Green LED for safe condition
const int redLEDPin = 4;        // Red LED for alert condition
const int buzzerPin = 5;        // Passive buzzer pin
int threshold = 700;            // Radiation alert threshold

void setup() {
  // Initialize LEDs and buzzer as outputs
  pinMode(greenLEDPin, OUTPUT);
  pinMode(redLEDPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

  // Initialize the LCD
  lcd.begin(16, 2);
  lcd.backlight();
  lcd.print("Radiation Monitor");
  delay(2000);

  // Initialize Serial Monitor for SMS display
  Serial.begin(9600);
  Serial.println("System Initialized.");
}

void loop() {
  int radiationLevel = analogRead(sensorPin); // Read the sensor value

  // Clear LCD rows before updating
  lcd.setCursor(0, 0);
  lcd.print("                "); // Clear the first row
  lcd.setCursor(0, 0);
  lcd.print("Radiation: ");
  lcd.print(radiationLevel);

  lcd.setCursor(0, 1);
  lcd.print("                "); // Clear the second row
  lcd.setCursor(0, 1);

  if (radiationLevel < threshold) {
    // Safe condition
    digitalWrite(greenLEDPin, HIGH);
    digitalWrite(redLEDPin, LOW);
    noTone(buzzerPin); // Turn off buzzer
    lcd.print("Status: Normal");

    // Print SMS-like message to Serial Monitor
    Serial.println("Status: Normal. Radiation levels are safe.");
  } else {
    // Alert condition
    digitalWrite(greenLEDPin, LOW);
    digitalWrite(redLEDPin, HIGH);

    // Continuous buzzer sound
    tone(buzzerPin, 1000); // 1 kHz tone for passive buzzer

    lcd.print("HIGH Radiation!");

    // Print SMS-like message to Serial Monitor
    Serial.println("ALERT: HIGH Radiation detected! Immediate action required.");
  }

  delay(1000); // Update every second
}