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

// Initialize 16x4 LCD (I2C address may vary)
LiquidCrystal_I2C lcd(0x27, 16, 4);  // Adjust address to 0x3F if needed

// Data wire for DS18B20
#define ONE_WIRE_BUS 2

// Setup oneWire instance
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

DeviceAddress tempSensor;

void setup() {
  Serial.begin(9600);
  
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();
  
  // Start DS18B20 sensor
  sensors.begin();
  
  // Check for temperature sensors
  if (!sensors.getDeviceCount()) {
    lcdPrintError("No sensor found!");
    while(1);
  }
  
  // Configure sensor resolution
  sensors.getAddress(tempSensor, 0);
  sensors.setResolution(tempSensor, 12);
  
  // Display header
  lcd.setCursor(0, 0);
  lcd.print("Digital Thermometer");
  lcd.setCursor(0, 1);
  lcd.print("----------------");
}

void loop() {
  sensors.requestTemperatures();
  float tempC = sensors.getTempC(tempSensor);
  
  // Check if reading is valid
  if(tempC == DEVICE_DISCONNECTED_C) {
    lcdPrintError("Sensor Error!");
    return;
  }
  
  updateDisplay(tempC);
  delay(1000);
}

void updateDisplay(float celsius) {
  float fahrenheit = (celsius * 9.0 / 5.0) + 32;
  
  // Clear previous temperature values
  lcd.setCursor(0, 2);
  lcd.print("                ");
  lcd.setCursor(0, 3);
  lcd.print("                ");
  
  // Display Celsius
  lcd.setCursor(3, 2);
  lcd.print(celsius, 1);
  lcd.write(223);  // Degree symbol
  lcd.print("C");
  
  // Display Fahrenheit
  lcd.setCursor(3, 3);
  lcd.print(fahrenheit, 1);
  lcd.write(223);
  lcd.print("F");

  // Serial monitor output
  Serial.print("Temperature: ");
  Serial.print(celsius, 1);
  Serial.print("°C / ");
  Serial.print(fahrenheit, 1);
  Serial.println("°F");
}

void lcdPrintError(const char *msg) {
  lcd.clear();
  lcd.setCursor(0, 1);
  lcd.print(msg);
}