temp_controller.cpp

// Stage durations in milliseconds
const unsigned long stageDurations[] = {
  4UL * 60UL * 60UL * 1000UL, // Stage 1
  6UL * 60UL * 60UL * 1000UL, // Stage 2
  8UL * 60UL * 60UL * 1000UL, // Stage 3
  3UL * 60UL * 60UL * 1000UL, // Stage 4
  1UL * 60UL * 60UL * 1000UL, // Stage 5
  4UL * 60UL * 60UL * 1000UL  // Stage 6
};

// Stage target temperatures
const float stageTemps[] = {
  20.0, // Stage 1
  25.0, // Stage 2
  30.0, // Stage 3
  40.0, // Stage 4
  50.0, // Stage 5
  60.0  // Stage 6
};

// -------------------- Includes --------------------
#include "LiquidCrystal.h"
#include "OneWire.h"
#include "DallasTemperature.h"

// -------------------- LCD Setup --------------------
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

// -------------------- Temperature Sensors --------------------
#define ONE_WIRE_BUS 7
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

// -------------------- Heater Relay Pins --------------------
#define HEATER_PIN_1 8
#define HEATER_PIN_2 9

// -------------------- Timing --------------------
unsigned long startTime;
unsigned long lastLcdInit = 0;

const int numStages = sizeof(stageDurations) / sizeof(stageDurations[0]);

// -------------------- Global Variables --------------------
float targetTemp = 0.0;
bool finished = false;

// -------------------- Setup --------------------
void setup() {
  lcd.begin(16, 2);
  sensors.begin();

  pinMode(HEATER_PIN_1, OUTPUT);
  pinMode(HEATER_PIN_2, OUTPUT);

  digitalWrite(HEATER_PIN_1, HIGH); // OFF at start
  digitalWrite(HEATER_PIN_2, HIGH);

  startTime = millis();
  lastLcdInit = millis();  // initialize tracking
}

// -------------------- Loop --------------------
void loop() {
  unsigned long elapsed = millis() - startTime;

  // Re-init LCD every 3 minutes
  if (millis() - lastLcdInit >= 180000UL) {  // 3 minutes
    lcd.begin(16, 2);
    lastLcdInit = millis();
  }

  // Determine current stage
  unsigned long accumulated = 0;
  int currentStage = -1;
  for (int i = 0; i < numStages; i++) {
    accumulated += stageDurations[i];
    if (elapsed < accumulated) {
      currentStage = i;
      break;
    }
  }

  if (currentStage != -1) {
    targetTemp = stageTemps[currentStage];
    finished = false;
  } else {
    // All stages complete - stop heating
    targetTemp = 0.0;
    finished = true;
    digitalWrite(HEATER_PIN_1, HIGH);
    digitalWrite(HEATER_PIN_2, HIGH);
  }

  // Read temperatures
  sensors.requestTemperatures();
  float temp1 = sensors.getTempCByIndex(0);
  float temp2 = sensors.getTempCByIndex(1);

  // Control heaters independently
  controlHeater(HEATER_PIN_1, temp1);
  controlHeater(HEATER_PIN_2, temp2);

  // Display temperatures
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("T1:");
  lcd.print(temp1, 1);
  lcd.print(" T2:");
  lcd.print(temp2, 1);

  // Second line: either show MT:XXC or "Gatavs"
  lcd.setCursor(0, 1);
  if (!finished) {
    lcd.print("MT:");
    lcd.print(targetTemp, 0);
    lcd.print("C  ");
  } else {
    lcd.print("Gatavs! "); // pad a bit so old text doesn't stay
  }

  // Elapsed time in HH:MM:SS
  unsigned long elapsedSeconds = elapsed / 1000UL;
  unsigned int hours   = elapsedSeconds / 3600UL;
  unsigned int minutes = (elapsedSeconds % 3600UL) / 60UL;
  unsigned int seconds = elapsedSeconds % 60UL;

  if (hours < 10) lcd.print("0");
  lcd.print(hours);
  lcd.print(":");
  if (minutes < 10) lcd.print("0");
  lcd.print(minutes);
  lcd.print(":");
  if (seconds < 10) lcd.print("0");
  lcd.print(seconds);

  delay(250); // Update
}

// -------------------- Heater Control Function --------------------
void controlHeater(int heaterPin, float currentTemp) {
  if (targetTemp > 0) { // Only if in heating phase
    if (currentTemp < targetTemp - 0.5) {
      digitalWrite(heaterPin, LOW);  // Turn heater ON (active LOW)
    } else if (currentTemp > targetTemp + 0.5) {
      digitalWrite(heaterPin, HIGH); // Turn heater OFF
    }
  } else {
    digitalWrite(heaterPin, HIGH); // Force OFF when not heating
  }
}