#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "RTClib.h"
RTC_DS3231 rtc;
char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 32 // OLED display height, in pixels
#define OLED_RESET 4
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
void setup() {
  Serial.begin(9600);
  delay(3000); // wait for console opening

  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }
  if (rtc.lostPower()) {
    Serial.println("RTC lost power, lets set the time!");
    // 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));
  }
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  // initialize with the I2C addr 0x3C (for the 128x32)// Check your I2C address and enter it here, in Our case address is 0x3C
  display.clearDisplay();
  display.display(); // this command will display all the data which is in buffer
  display.setTextColor(WHITE, BLACK);
  display.drawRect(117, 25, 3, 3, WHITE);     // Put degree symbol ( ° )
  draw_text(0, 25, "TEMPERATURE =", 1);
  draw_text(122, 25, "C", 1);
}
void loop() {
  DateTime now = rtc.now();
  /*============Display Date=================*/
display.setTextSize(1);
display.setCursor(0,0);
display.print(daysOfTheWeek[now.dayOfTheWeek()]);
char currentDate [16];
uint8_t thisDay, thisMonth ;
thisDay = now.day();
thisMonth = now.month();
sprintf (currentDate, "%02d/%02d/", thisDay, thisMonth); //add leading zeros to the day and month
display.setTextSize(1);
display.setCursor(62,0);
display.print(currentDate);
display.setTextSize(1);
display.setCursor(102,0);
display.print(now.year(), DEC);
/*================Display Time================*/ 
char buffer [16];
uint8_t thisSec, thisMin, thisHour;
thisSec = now.second(); 
thisMin = now.minute(); // minutes
thisHour = now.hour();  // hours

decToBinary(thisHour, 2);
decToBinary(thisMin, 6);


sprintf (buffer, "%02d:%02d:%02d", thisHour, thisMin, thisSec);
display.setTextSize(2);
display.setCursor(15,9);
display.print(buffer);
/*=============Display Temperature=====================*/
display.setTextSize(1);
display.setCursor(82,25);
display.print(rtc.getTemperature());
display.display(); 
}
void draw_text(byte x_pos, byte y_pos, char *text, byte text_size) {
  display.setCursor(x_pos, y_pos);
  display.setTextSize(text_size);
  display.print(text);
  display.display();
}
int decToBinary(uint8_t n, int y)
{
  int x = y;
    // Size of an integer is assumed to be 8 bits
    for (int i = 7; i >= 0; i--) {
        int k = n >> i; // right shift
        if (k & 1) // helps us know the state of first bit
              digitalWrite(x, HIGH);
        else digitalWrite(x, LOW);
        x++;
    }
}