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

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Replace 0x27 with the actual LCD address if needed

const int TRIGGER = 23;  // GPIO pin for ultrasonic sensor trigger
const int ECHO = 22;     // GPIO pin for ultrasonic sensor echo
const int buzzerPin = 21;  // GPIO pin for buzzer
const int ledPin = 19;    // GPIO pin for LED (both temperature and ultrasonic)

const float temperatureThreshold = 36.0;  // Threshold for temperature alerts

const int REF_VIN = 3.3;
const int lm35Pin = 34;  // GPIO pin for LM35 sensor

float getTemperature() {
  float voltage = analogRead(lm35Pin);
  float tmpVal = (voltage / 1023.0) * REF_VIN * 100;
  return tmpVal;
}

float getDistance() {
  digitalWrite(TRIGGER, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER, LOW);

  long duration = pulseIn(ECHO, HIGH);
  float distance = (duration / 2) / 29.1;
  return distance;
}

void setup() {
  Serial.begin(115200);

  // Initialize I2C with non-standard pins
  Wire.begin(18, 5);  // Use GPIO 18 for SDA and GPIO 5 for SCL

  // Pin mode setup
  pinMode(TRIGGER, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);

  lcd.begin(16, 2);  // Initialize LCD with 16 columns and 2 rows
}

void loop() {
  float temperature = getTemperature();
  float distance = getDistance();

  // Print to serial monitor
  Serial.print("Temp: ");
  Serial.print(temperature);
  Serial.println("C");

  // Display on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print("C");

  // Handle temperature alerts
  if (temperature > temperatureThreshold) {
    // Temperature above threshold
    Serial.println("Red Alert!");
    lcd.setCursor(0, 1);
    lcd.print("Red Alert!");
    digitalWrite(ledPin, HIGH);  // Blink LED
   
  } 
  if (temperature < temperatureThreshold) {
    // Temperature below or equal to threshold
    Serial.println("Door Open");
    lcd.setCursor(0, 1);
    lcd.print("Door Open");
    digitalWrite(ledPin, LOW);  // Turn off LED
     tone(buzzerPin, 1000, 500);  // Ring buzzer
  }

  // Handle ultrasonic LED
  if (distance <= 30) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }

  delay(2000);  // Adjust the delay based on your needs
}