#include <TM1637Display.h>


#define CLK 2
#define DIO 3


#define START_BUTTON_PIN 4
#define STOP_BUTTON_PIN 5
#define RESET_BUTTON_PIN 6

TM1637Display display(CLK, DIO);


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

void setup() {
  pinMode(START_BUTTON_PIN, INPUT_PULLUP);
  pinMode(STOP_BUTTON_PIN, INPUT_PULLUP);
  pinMode(RESET_BUTTON_PIN, INPUT_PULLUP);

  display.setBrightness(0x0a); 

  display.showNumberDec(0);
}

void loop() {
  
  if (digitalRead(START_BUTTON_PIN) == LOW && !isRunning) {
    startTime = millis() - elapsedTime;
    isRunning = true;
  }

  // Check stop button
  if (digitalRead(STOP_BUTTON_PIN) == LOW && isRunning) {
    elapsedTime = millis() - startTime;
    isRunning = false;
  }

  
  if (digitalRead(RESET_BUTTON_PIN) == LOW) {
    isRunning = false;
    elapsedTime = 0;
    display.showNumberDec(0);
  }

 
  if (isRunning) {
    unsigned long currentTime = millis() - startTime;
    display.showNumberDecEx(currentTime / 1000, 0b01000000, true);
  }

  delay(10); 
}