#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Initialize the I2C LCD (address 0x27, 16 columns, 2 rows)
LiquidCrystal_I2C lcd(0x27, 16, 2);

const int startButton = 8;
const int stopButton = 9;
const int resetButton = 10;

bool running = false;
unsigned long startTime = 0;
unsigned long elapsedTime = 0;

void setup() {
  pinMode(startButton, INPUT);
  pinMode(stopButton, INPUT);
  pinMode(resetButton, INPUT);

  lcd.init();            // Initialize the LCD
  lcd.backlight();       // Turn on the backlight
  lcd.print("Micro Timer");
  delay(2000);
  lcd.clear();
}

void loop() {
  // Check if the Start button is pressed
  if (digitalRead(startButton) == HIGH && !running) {
    running = true;
    startTime = micros();  // Record start time in microseconds
  }

  // Check if the Stop button is pressed
  if (digitalRead(stopButton) == HIGH && running) {
    running = false;
    elapsedTime += micros() - startTime;  // Add elapsed time to total
  }

  // Check if the Reset button is pressed
  if (digitalRead(resetButton) == HIGH) {
    running = false;
    elapsedTime = 0;
  }

  // Display elapsed time
  lcd.setCursor(0, 0);
  lcd.print("Elapsed:");

  if (running) {
    unsigned long currentTime = micros();
    displayTime(elapsedTime + currentTime - startTime);
  } else {
    displayTime(elapsedTime);
  }

  delay(100);  // Small delay to avoid bouncing
}

// Function to display time in seconds and microseconds
void displayTime(unsigned long time) {
  lcd.setCursor(0, 1);
  lcd.print(time / 1000000);  // Print seconds
  lcd.print(".");
  lcd.print((time / 1000) % 1000);  // Print milliseconds
  lcd.print("s   ");  // Clear extra chars
}