// LCD1602 to Arduino Uno connection example

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 10, 9, 8, 7);
unsigned long mulai, selesai, dataStopWatch;
int i=0;
int fPaus=0;
long lastButton=0;
long delayAntiBouncing=50;
long dataPaus =0;

void setup() {
pinMode(A0, INPUT);
pinMode(A1, INPUT);
digitalWrite(A0, 1);
digitalWrite(A1, 1);
lcd.begin(16, 2);

lcd.setCursor(0, 0);
lcd.print(" ARDUINO");
lcd.setCursor(0, 1);
lcd.print(" StopWatch");
delay(2000);
lcd.clear();
lcd.print(" tekan tombol ");
lcd.setCursor(0, 1);
lcd.print("star / stop");
}

void loop() {
  // ...
  if (digitalRead(A0)==0){
  if ((millis() - lastButton) > delayAntiBouncing){
   if(i==0){
     lcd.clear();
     lcd.setCursor(0, 0);
     lcd.print("Start Timer");
     mulai = millis();
     fPaus = 0;
   }
   else if (i==1){
     lcd.setCursor(0, 0);
     lcd.print("Stop Timer");
     dataPaus = dataStopWatch;
     fPaus=1;
   }
  i=!i;
  }
  lastButton = millis();
}
else if (digitalRead(A1)==0 && fPaus == 1){
  dataStopWatch = 0;
  dataPaus=0;
  lcd.clear();
  lcd.print("Reset Stopwatch");
  lcd.setCursor(0, 1);
  lcd.print("0:0:0:0");
  delay(2000);
  lcd.clear();
  lcd.print("Tekan Tombol");
  lcd.setCursor(0, 1);
  lcd.print("Start / Stop");
}

if (i == 1){
  selesai = millis();
  float jam, menit, detik, miliDetik;
  unsigned long over;

  dataStopWatch = selesai - mulai;
  dataStopWatch = dataPaus + dataStopWatch;

  jam = int(dataStopWatch / 3600000);
  jam = dataStopWatch % 3600000;
  menit = int(over / 60000);
  detik = int(over / 1000);
  miliDetik = over % 1000;

  lcd.setCursor(0, 1);
  lcd.print(jam, 0);
  lcd.print(":");
  lcd.print(menit, 0);
  lcd.print(":");
  lcd.print(detik, 0);
  lcd.print(".");
  if(jam < 10){
    lcd.print(miliDetik, 0);
    lcd.print(" ");
  }
}}