#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2); // Initialize the LCD

const int startStopButtonPin = 2; // Pin for start/stop button
const int resetButtonPin = 3;     // Pin for reset button

unsigned long startTime = 0;  // Variable to store the start time
unsigned long elapsedTime = 0;  // Variable to store the elapsed time
bool isRunning = false;  // Flag to indicate if the stopwatch is running

void setup() {
  lcd.begin(16, 2); // Set up the LCD columns and rows
  lcd.print("Press Start"); // Display initial message
  pinMode(startStopButtonPin, INPUT_PULLUP); // Set start/stop button pin as input with pull-up resistor
  pinMode(resetButtonPin, INPUT_PULLUP); // Set reset button pin as input with pull-up resistor
}

void loop() {
  if (digitalRead(startStopButtonPin) == LOW) {
    if (!isRunning) {
      startTime = millis(); // Start the stopwatch
      isRunning = true;
      lcd.clear();
    } else {
      isRunning = false; // Stop the stopwatch
    }
    delay(200); // Debounce delay
  }

  if (digitalRead(resetButtonPin) == LOW) {
    if (!isRunning) {
      elapsedTime = 0; // Reset the stopwatch
      lcd.clear();
      lcd.print("Press Start");
    }
    delay(200); // Debounce delay
  }

  if (isRunning) {
    // Calculate elapsed time
    unsigned long currentTime = millis();
    elapsedTime = currentTime - startTime;

    // Display elapsed time on the LCD
    lcd.setCursor(0, 0);
    lcd.print("Time: ");
    lcd.setCursor(6, 0);
    lcd.print(elapsedTime / 1000); // Convert milliseconds to seconds
    lcd.print(" s");
  }
}