/**************************************************************************
 This is an example for our Monochrome OLEDs based on SSD1306 drivers

 Pick one up today in the adafruit shop!
 ------> http://www.adafruit.com/category/63_98

 This example is for a 128x64 pixel display using I2C to communicate
 3 pins are required to interface (two I2C and one reset).

 Adafruit invests time and resources providing this open
 source code, please support Adafruit and open-source
 hardware by purchasing products from Adafruit!

 Written by Limor Fried/Ladyada for Adafruit Industries,
 with contributions from the open source community.
 BSD license, check license.txt for more information
 All text above, and the splash screen below must be
 included in any redistribution.
 **************************************************************************/

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define button1    2                       // Button B1 is connected to Arduino pin 9
#define button2    15                      // Button B2 is connected to Arduino pin 8

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);


void setup(void) {
  pinMode(button1, INPUT_PULLUP);
  pinMode(button2, INPUT_PULLUP);
  delay(1000);
 
  // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  // initialize with the I2C addr 0x3D (for the 128x64)
  // init done
 
  // Clear the display buffer.
  display.clearDisplay();
  display.display();
 
  display.setTextColor(WHITE, BLACK);
}
 
char Time[]     = "  :  :  ";
char Calendar[] = "  /  /20  ";
byte i, second, minute, hour, day, date, month, year;
 
void display_day(){
  switch(day){
    case 1:  draw_text(40, 0, " SUNDAY  ", 1); break;
    case 2:  draw_text(40, 0, " MONDAY  ", 1); break;
    case 3:  draw_text(40, 0, " TUESDAY ", 1); break;
    case 4:  draw_text(40, 0, "WEDNESDAY", 1); break;
    case 5:  draw_text(40, 0, "THURSDAY ", 1); break;
    case 6:  draw_text(40, 0, " FRIDAY  ", 1); break;
    default: draw_text(40, 0, "SATURDAY ", 1);
  }
}
 
void DS1307_display(){
  // Convert BCD to decimal
  second = 20;
  minute = 10;
  hour   = 13;
  date   = 2;
  month  = 5;
  year   = 22;
  // End conversion
 
  Time[7]     = second % 10 + 48;
  Time[6]     = second / 10 + 48;
  Time[4]     = minute % 10 + 48;
  Time[3]     = minute / 10 + 48;
  Time[1]     = hour   % 10 + 48;
  Time[0]     = hour   / 10 + 48;
  Calendar[9] = year   % 10 + 48;
  Calendar[8] = year   / 10 + 48;
  Calendar[4] = month  % 10 + 48;
  Calendar[3] = month  / 10 + 48;
  Calendar[1] = date   % 10 + 48;
  Calendar[0] = date   / 10 + 48;
 
  draw_text(4,  18, Calendar, 2);
  draw_text(16, 42, Time, 2);
}
 
void blink_parameter(){
  byte j = 0;
  while(j < 10 && digitalRead(button1) && digitalRead(button2)){
    j++;
    delay(25);
  }
}
 
byte edit(byte x_pos, byte y_pos, byte parameter){
  char text[3];
  sprintf(text,"%02u", parameter);
  while(!digitalRead(button1));                      // Wait until button B1 released
  while(true){
    while(!digitalRead(button2)){                    // If button B2 is pressed
      parameter++;
      if(i == 0 && parameter > 31)                   // If date > 31 ==> date = 1
        parameter = 1;
      if(i == 1 && parameter > 12)                   // If month > 12 ==> month = 1
        parameter = 1;
      if(i == 2 && parameter > 99)                   // If year > 99 ==> year = 0
        parameter = 0;
      if(i == 3 && parameter > 23)                   // If hours > 23 ==> hours = 0
        parameter = 0;
      if(i == 4 && parameter > 59)                   // If minutes > 59 ==> minutes = 0
        parameter = 0;
      sprintf(text,"%02u", parameter);
      draw_text(x_pos, y_pos, text, 2);
      delay(200);                                    // Wait 200ms
    }
    draw_text(x_pos, y_pos, "  ", 2);
    blink_parameter();
    draw_text(x_pos, y_pos, text, 2);
    blink_parameter();
    if(!digitalRead(button1)){                       // If button B1 is pressed
      i++;                                           // Increament 'i' for the next parameter
      return parameter;                              // Return parameter value and exit
    }
  }
}
 
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();
}
 
void loop() {
 
  if(!digitalRead(button1)){                         // If button B1 is pressed
    i = 0;
    while(!digitalRead(button1));                    // Wait for button B1 release
    while(true){
      while(!digitalRead(button2)){                  // While button B2 pressed
        day++;                                       // Increment day
        if(day > 7) day = 1;
        display_day();                               // Call display_day function
        delay(200);                                  // Wait 200 ms
      }
      draw_text(40, 0, "         ", 1);
      blink_parameter();                             // Call blink_parameter function
      display_day();                                 // Call display_day function
      blink_parameter();                             // Call blink_parameter function
      if(!digitalRead(button1))                      // If button B1 is pressed
        break;
    }
 
    date   = edit(4, 18, date);                      // Edit date
    month  = edit(40, 18, month);                    // Edit month
    year   = edit(100, 18, year);                    // Edit year
    hour   = edit(16, 42, hour);                     // Edit hours
    minute = edit(52, 42, minute);                   // Edit minutes
 
    // Convert decimal to BCD
    minute = ((minute / 10) << 4) + (minute % 10);
    hour = ((hour / 10) << 4) + (hour % 10);
    date = ((date / 10) << 4) + (date % 10);
    month = ((month / 10) << 4) + (month % 10);
    year = ((year / 10) << 4) + (year % 10);
    // End conversion
 
    // Write data to DS1307 RTC
    Wire.beginTransmission(0x68);               // Start I2C protocol with DS1307 address
    Wire.write(0);                              // Send register address
    Wire.write(0);                              // Reset sesonds and start oscillator
    Wire.write(minute);                         // Write minute
    Wire.write(hour);                           // Write hour
    Wire.write(day);                            // Write day
    Wire.write(date);                           // Write date
    Wire.write(month);                          // Write month
    Wire.write(year);                           // Write year
    Wire.endTransmission();                     // Stop transmission and release the I2C bus
    delay(200);                                 // Wait 200ms
  }
 
  Wire.beginTransmission(0x68);                 // Start I2C protocol with DS1307 address
  Wire.write(0);                                // Send register address
  Wire.endTransmission(false);                  // I2C restart
  Wire.requestFrom(0x68, 7);                    // Request 7 bytes from DS1307 and release I2C bus at end of reading
  second = Wire.read();                         // Read seconds from register 0
  minute = Wire.read();                         // Read minuts from register 1
  hour   = Wire.read();                         // Read hour from register 2
  day    = Wire.read();                         // Read day from register 3
  date   = Wire.read();                         // Read date from register 4
  month  = Wire.read();                         // Read month from register 5
  year   = Wire.read();                         // Read year from register 6
 
  display_day();
  DS1307_display();                             // Diaplay time & calendar
 
  delay(50);                                    // Wait 50ms 
}
// End of code.