#include <glcd.h>
#include <OneWire.h>
#include <DallasTemperature.h>

// DS18B20 on digital pin 12
#define ONE_WIRE_BUS 12
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

// Button pins
#define BUTTON_UP  A4
#define BUTTON_DOWN A5

// Relay or output pin
#define RELAY_PIN 13

// Variables
int setTemp = 25;
unsigned long lastDebounce = 0;
const int debounceDelay = 200;

void setup() {
  GLCD.Init();
  sensors.begin();
  
  pinMode(BUTTON_UP, INPUT_PULLUP);
  pinMode(BUTTON_DOWN, INPUT_PULLUP);
  pinMode(RELAY_PIN, OUTPUT);

  GLCD.ClearScreen();
  GLCD.SelectFont(System5x7);  // Use small font to fit more text
}

void loop() {
  // Simple debounce
  if (millis() - lastDebounce > debounceDelay) {
    if (digitalRead(BUTTON_UP) == LOW) {
      setTemp++;
      lastDebounce = millis();
    }
    if (digitalRead(BUTTON_DOWN) == LOW) {
      setTemp--;
      lastDebounce = millis();
    }
  }

  // Read temperature
  sensors.requestTemperatures();
  float currentTemp = sensors.getTempCByIndex(0);

  // Control output
  if (currentTemp < setTemp) {
    digitalWrite(RELAY_PIN, HIGH);
  } else {
    digitalWrite(RELAY_PIN, LOW);
  }

  // Display on GLCD
  GLCD.ClearScreen();

  // Draw labels
  GLCD.CursorTo(0, 0);
  GLCD.print("DIGITAL THERMOSTAT");

  GLCD.CursorTo(0, 2);
  GLCD.print("Current: ");
  GLCD.print(currentTemp, 1);
  GLCD.print((char)223); // Degree symbol
  GLCD.print("C");

  GLCD.CursorTo(0, 4);
  GLCD.print("Set Temp: ");
  GLCD.print(setTemp);
  GLCD.print((char)223);
  GLCD.print("C");

  GLCD.CursorTo(0, 6);
  GLCD.print("Heater: ");
  GLCD.print((currentTemp < setTemp) ? "ON " : "OFF");

  delay(500); // Keep display readable and stable
}