#include "RTClib.h"
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4

LiquidCrystal_I2C lcd(0x27, 20, 4);
Adafruit_SSD1306 display(128, 64, &Wire, 4);
RTC_DS1307 rtc;

String dow[7] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};

void setup() {
  Serial.begin(115200);
  rtc.begin();
  lcd.begin(16, 2);
  lcd.backlight();

  display.begin(SSD1306_SWITCHCAPVCC, 0x3c);
  display.setTextSize(1);
  display.setTextColor(WHITE);
}

void loop() {
  DateTime now = rtc.now();
  int dd = now.day();
  int mm = now.month();
  int yy = now.year();
  int hr = now.hour();
  int mn = now.minute();
  int sc = now.second();
  String dw = dow[now.dayOfTheWeek()];
  char buff[11];
  String d, t;
  sprintf(buff, "%02d/%02d/%d", dd, mm, yy);
  d  = String(buff);
  sprintf(buff, "%02d:%02d:%02d", hr, mn, sc);
  t = String(buff);
//  String d = String(dd) + "/" + String(mm) + "/" + String(yy);
//  String t = "";
//  if (hr < 10) {
//    t += "0";
//  }
//  t = t + String(hr) + ":";
//  if ( mn < 10) {
//    t += "0";
//  }
//  t = t + String(mn) + ":";
//  if (sc < 10) {
//    t += "0";
//  }
//  t = t + String(sc);
  //string t = string(hr) + ":" + string(mn) + ":" + string(sc);
  Serial.println(d + " " + t);
  lcd.setCursor(0, 1); lcd.print(d);
  lcd.setCursor(0, 1); lcd.print(t);

  display.clearDisplay();
  display.setCursor(0, 0); display.println(d);
  display.setCursor(0, 10); display.println(t);
  display.display();
  delay(1000);
}