#include <LiquidCrystal.h>

// Define pins for buttons
const int startButtonPin = 2;
const int stopButtonPin = 3;
const int resetButtonPin = 4;

// Define pins for LCD
const int rs = 7;
const int en = 8;
const int d4 = 9;
const int d5 = 10;
const int d6 = 11;
const int d7 = 12;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

// Define buzzer pin
const int buzzerPin = 6;

// Define activities and their corresponding timers (less than 10 seconds)
const char* activities[] = {"Activity 1", "Activity 2", "Activity 3"};
const int activityTimers[] = {5, 7, 9}; // in seconds

// Variables
int currentActivityIndex = -1;
unsigned long countdownEndTime = 0;
bool countdownActive = false;
bool stopButtonPressed = false;
bool buzzerActive = false;

void setup() {
  // Initialize LCD
  lcd.begin(16, 2);
  lcd.print("Press Start");
  
  // Initialize buttons
  pinMode(startButtonPin, INPUT_PULLUP);
  pinMode(stopButtonPin, INPUT_PULLUP);
  pinMode(resetButtonPin, INPUT_PULLUP);
  
  // Initialize buzzer
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  // Check for button presses
  if (digitalRead(startButtonPin) == LOW && !countdownActive) {
    startActivity();
  }

  if (digitalRead(stopButtonPin) == LOW) {
    if (countdownActive) {
      stopButtonPressed = true;
      stopActivity();
    } else if (buzzerActive) {
      resetActivity();
    }
  }

  if (digitalRead(resetButtonPin) == LOW) {
    if (countdownActive || buzzerActive) {
      buzzerActive = false;
      resetActivity();
    }
  }

  // Check if the stop button was released after being pressed
  if (digitalRead(stopButtonPin) == HIGH && stopButtonPressed) {
    stopButtonPressed = false;
    countdownActive = false;
  }

  // Check countdown and update display
  if (countdownActive) {
    unsigned long currentTime = millis();
    if (currentTime >= countdownEndTime) {
      // Countdown reached 0
      countdownActive = false;
      buzzerActive = true;
      lcd.clear();
      lcd.print("Press Reset/Stop");
      activateBuzzer();
    } else {
      // Display remaining time
      int remainingTime = (countdownEndTime - currentTime) / 1000; // Convert to seconds
      updateLCD(remainingTime);
    }
  }
}

void startActivity() {
  currentActivityIndex = random(0, sizeof(activities) / sizeof(activities[0]));
  int activityTimer = activityTimers[currentActivityIndex];
  countdownEndTime = millis() + (activityTimer * 1000);
  countdownActive = true;
  buzzerActive = false;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(activities[currentActivityIndex]);
  updateLCD(activityTimer);
  noTone(buzzerPin);
}

void stopActivity() {
  countdownActive = false;
  noTone(buzzerPin);
  lcd.clear();
  lcd.print("Press Start");
}

void resetActivity() {
  startActivity();
}

void updateLCD(int remainingTime) {
  lcd.setCursor(0, 1);
  lcd.print("Time: ");
  if (remainingTime < 10) {
    lcd.print("0");
  }
  lcd.print(remainingTime);
  lcd.print("s");
}

void activateBuzzer() {
  while ((buzzerActive && digitalRead(stopButtonPin) == HIGH) || (buzzerActive && digitalRead(resetButtonPin) == HIGH) ) {
    tone(buzzerPin, 1000); // Activate the buzzer at 1000 Hz
    
  }
}
test