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

const int SENSOR_PIN = 13; // Arduino pin connected to DS18B20 sensor's DQ pin
const int SERVO_PIN  = 2; // Arduino pin connected to Servo Motor's pin
const float TEMPERATURE_THRESHOLD = 20; // °C

OneWire oneWire(SENSOR_PIN);         // setup a oneWire instance
DallasTemperature sensors(&oneWire); // pass oneWire to DallasTemperature library
LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27, 16 column and 2 rows

Servo servo; // create servo object to control a servo
DallasTemperature sensor(&oneWire); // pass oneWire to DallasTemperature library
float temperature;
int angle;

float tempCelsius;    // temperature in Celsius
float tempFahrenheit; // temperature in Fahrenheit

void setup() {
    sensors.begin();    // initialize the sensor
  lcd.init();         // initialize the lcd
  lcd.backlight();    // open the backlight 

  Serial.begin(9600);      // initialize serial
  servo.attach(SERVO_PIN); // attaches the servo on pin 9 to the servo object
  servo.write(0);
  sensor.begin();          // initialize the sensor
}

void loop() {
    sensors.requestTemperatures();             // send the command to get temperatures
  tempCelsius = sensors.getTempCByIndex(0);  // read temperature in Celsius
  tempFahrenheit = tempCelsius * 9 / 5 + 32; // convert Celsius to Fahrenheit

  if (temperature > TEMPERATURE_THRESHOLD)
    angle = 90; // set angle to 90 degree
  else
    angle = 0;  // set angle to 0 degree

  servo.write(angle);  // rotate servo motor

  // print to serial
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print("°C => servo angle: ");
  Serial.println(angle);

  lcd.clear();
  lcd.setCursor(0, 0);       // start to print at the first row
  lcd.print(tempCelsius);    // print the temperature in Celsius
  lcd.print((char)223);      // print ° character
  lcd.print("C");
  lcd.setCursor(0, 1);       // start to print at the second row
  lcd.print(tempFahrenheit); // print the temperature in Fahrenheit
  lcd.print((char)223);      // print ° character
  lcd.print("F");

  delay(500);
}