#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);

#include "RTClib.h"
RTC_DS1307 rtc;
char daysOfTheWeek[7][12] = {"Minggu", "Senin", "Selasa", "Rabu", "Kamis", "Jumat", "Sabtu"};

#define buttondatetime 4
#define buttonstopwatch 2
#define buttonstart 15
#define led 5

int stopwatch;
int datetime;
int statusonoff;
int statusreset;
//int statusreset;
String swState = "OFF";
//int dataValue=0;
//int presState=0;
int miliSecond=0;
int second=0;
int minute=0;
int hour=0;

void setup() {
  pinMode(led, OUTPUT);
  pinMode(buttondatetime, INPUT_PULLUP);
  pinMode(buttonstopwatch, INPUT_PULLUP);
  pinMode(buttonstart, INPUT_PULLUP);

  Wire.begin();
  rtc.begin();
  //DateTime dt(2020, 10, 17, 20, 03, 0, 7); // set tanggal dan waktu (format): tahun, bulan,tanggal, jam, menit, detik, hari (1=minggu, 7=sabtu)
  //rtc.setDateTime(dt);
   
  Wire.beginTransmission(0x3F);
  if (Wire.endTransmission())
  {
    lcd = LiquidCrystal_I2C(0x27, 16, 2);
  }
  lcd.init();    
  lcd.backlight();
  
  Serial.begin(9600);
  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    Serial.flush();
    abort();
  }

  if (! rtc.isrunning()) {
    Serial.println("RTC is NOT running, let's set the time!");
    // When time needs to be set on a new device, or after a power loss, the
    // following line sets the RTC to the date & time this sketch was compiled
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
    // This line sets the RTC with an explicit date & time, for example to set
    // January 21, 2014 at 3am you would call:
    // rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
  }
  //lcddatetime();
  //stopwatchOff();
}

void loop() {
  //lcddatetime();
  //delay(1000);
  datetime = digitalRead(buttondatetime);
  stopwatch = digitalRead(buttonstopwatch);
  statusonoff = digitalRead(buttonstart);
  //statusreset = digitalRead(buttonstopwatch);

  if(datetime==LOW){
    lcd.clear();
    lcddatetime();
    delay(1000);
    
  }

    if(stopwatch==LOW){
    lcd.clear();
    stopwatchOff();
    reset();
    digitalWrite(led, LOW);
    }
    if(statusonoff==LOW ){
      if (swState=="OFF"){
          swState="ON ";
          digitalWrite(led, HIGH);
      } else if (swState=="ON "){
          swState="OFF";
          digitalWrite(led, LOW);
      }
      
      lcd.setCursor(13,0);
      lcd.println(swState);
      delay(200);
    } 

    if(swState=="ON "){
      lcdstopwatch();
    }

    if(swState=="OFF"){
      reset();
    }
  
}

void lcddatetime() {
  DateTime now = rtc.now();

    lcd.setCursor(9, 0);
    lcd.println(daysOfTheWeek[now.dayOfTheWeek()]); //tampilan hari
    lcd.setCursor(0, 1);
    if(now.day()<10){
      lcd.print("0");
    }
    lcd.print(now.day(), DEC); // tanggal
    lcd.print("/");
    if(now.month()<10){
      lcd.print("0");
    }
    lcd.print(now.month(), DEC);//bulan 
    lcd.print("/");
    lcd.print(now.year(), DEC); //tahun

  lcd.setCursor(0, 0);
    if(now.hour()<10){
      lcd.print("0");
    }
    lcd.print(String(now.hour()));
    lcd.print(":");
    if(now.minute()<10){
      lcd.print("0");
    }
    lcd.print(String(now.minute()));
    lcd.print(":");
    if(now.second()<10){
      lcd.print("0");
    }
    lcd.print(String(now.second()));
}

void lcdstopwatch() {
  miliSecond++;
  if(miliSecond>5){
    miliSecond=0;
    second++;
  }
  lcd.setCursor(11,1);
  if(miliSecond<10){
    lcd.print("0");
  }
  lcd.print(miliSecond);
  if(second>11){
    second=0;
    minute++;
  }
  lcd.setCursor(8,1);
  if(second<10){
    lcd.print("0");
  }
  lcd.print(second);
  if(minute>5){
    minute=0;
    hour++;
  }
  lcd.setCursor(5,1);
  if(minute<10){
    lcd.print("0");
  }
  lcd.print(minute);
  if(hour>11){
    hour=0;
  }
  lcd.setCursor(2,1);
  if(hour<10){
    lcd.print("0");
  }
  lcd.print(hour);
}

void stopwatchOff() {
  lcd.setCursor(0,0);
  lcd.println("STOP WATCH : OFF");
  lcd.setCursor(2,1);
  lcd.println("00:00:00:00");
}

void reset(){
  swState="OFF";
  int miliSecond=0;
  int second=0;
  int minute=0;
  int hour=0;
}