#include <PID_v1.h>
#include <U8g2lib.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <Encoder.h>

// Pin Definitions
#define HEATING_ELEMENT_PIN 6 // Example pin for the heating element
#define BUTTON_PIN 7 // Pin for the on-off button
#define DS18B20_DATA_PIN 5 // Digital pin connected to DQ of DS18B20 sensor (Arduino Nano pin D5)

// Encoder Pin Definitions
#define ENCODER_PIN1 A0 // Encoder pin 1
#define ENCODER_PIN2 A1 // Encoder pin 2

// PID Variables
double setpoint, input, output;
double Kp = 2, Ki = 5, Kd = 1; // PID Tuning Parameters
PID myPID(&input, &output, &setpoint, Kp, Ki, Kd, DIRECT);

// Encoder Setup
Encoder encoder(ENCODER_PIN1, ENCODER_PIN2);
int lastEncoderPos = -999;
int encoderPos = 0;

// Display Setup (Change according to your specific OLED display)
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0); // OLED display object

// DS18B20 sensor setup
OneWire oneWire(DS18B20_DATA_PIN); // Initialize a OneWire instance
DallasTemperature sensors(&oneWire); // Pass OneWire reference to DallasTemperature library

// Other Variables
bool heatingOn = false;

void setup() {
  // Initialize Serial communication
  Serial.begin(9600);

  // Initialize heating element pin and button pin
  pinMode(HEATING_ELEMENT_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  // Set the initial setpoint temperature
  setpoint = 200; // Default setpoint temperature

  // Initialize PID
  myPID.SetMode(AUTOMATIC);

  // Initialize Encoder pins
  // ... (Encoder pin initialization)

  // Initialize OLED display
  u8g2.begin();
  u8g2.setFont(u8g2_font_ncenB08_tr); // Choose font size and type

  // Start DS18B20 sensor communication
  sensors.begin();
  displayTemperature(); // Display initial temperature
}

void loop() {
  encoderPos = encoder.read() / 4; // Divide by 4 for finer adjustment

  if (encoderPos != lastEncoderPos) {
    setpoint = map(encoderPos, 0, 100, 190, 210);
    displayTemperature();
    lastEncoderPos = encoderPos;
  }

  input = readTemperatureSensor(); // Function to read temperature from sensor
  myPID.Compute();

  if (digitalRead(BUTTON_PIN) == LOW) {
    heatingOn = !heatingOn; // Toggle heating element state
    delay(250); // Debounce delay for the button press
  }

  if (heatingOn) {
    analogWrite(HEATING_ELEMENT_PIN, output);
  } else {
    analogWrite(HEATING_ELEMENT_PIN, 0);
  }
}

void displayTemperature() {
  // Clear display and print the setpoint temperature
  u8g2.firstPage();
  do {
    u8g2.setCursor(0, 20);
    u8g2.print("Setpoint Temp:");
    u8g2.setCursor(0, 40);
    u8g2.print(setpoint);
    u8g2.print(" C");
  } while (u8g2.nextPage());
}

double readTemperatureSensor() {
  sensors.requestTemperatures(); // Send the command to get temperature readings
  double tempC = sensors.getTempCByIndex(0); // Get temperature in Celsius
  return tempC; // Return temperature value
}