#include <LiquidCrystal.h>
#include <Wire.h>
//  LiquidCrystal(RS,RW,EN,d0,d1,d2,d3,d4,d5,d6,d7)
LiquidCrystal lcd(24,23,22,37,36,35,34,33,32,31,30); // initialize the LCD as per Section2
#define RTC 0x68 // set 7-bit I2C address for RTC
char *d_o_t_w[8] = {"N/A      ","Sunday   ", "Monday   ", "Tuesday  ", "Wednesday", "Thursday ", "Friday   ", "Saturday "};
int dmyhms[6] = {31, 12, 99, 11, 59, 45};
int date = 0;


//**********************************************************************
// Some global variables declared and initialized here.
//**********************************************************************
// RTC variables
int ampm=0;
//**********************************************************************
void setup()
{
  lcd.begin(20,4); delay(2); // Initialize the LCD
  delay(500);
  lcd.setCursor(1, 0); // Start LCD at Col. 1, Line 0 (top line)
  // lcd.print("Lab 3: RTC and I2C Lab");
  // I2C setup
  Wire.begin();
  RTC_init(); // Initialize DS1307 RTC
}

//**********************************************************************
void loop()
{
  RTC_read();
  lcd.setCursor(1, 1);

  if(date == 0)
    date++;

  lcd.print(d_o_t_w[date]);
  

  lcd.setCursor(1, 2);
  
  
  if (dmyhms[3]<10)
    lcd.print('0'); // Pad hours with '0'
  
  lcd.print(dmyhms[3] & 0x3F,HEX); // Mask out top 3 bits then hours to LCD
  lcd.print(":");
  

  if (dmyhms[4]<10)
    lcd.print('0'); // Pad minutes with '0'
  
  lcd.print(dmyhms[4],HEX); // Minutes to LCD
  lcd.print(":");
  

  if (dmyhms[5]<10)
    lcd.print('0'); // Pad seconds with '0'
  
  lcd.print(dmyhms[5],HEX); // Seconds to LCD


  ampm = dmyhms[3] & 0x20; // Maskout all values but the am/pm bit
  if (ampm == 0x20)
    lcd.print("pm ");
  else
    lcd.print("am ");
  

  lcd.setCursor(1, 3);
  
  
  if(dmyhms[0] < 10)
    lcd.print('0');
    
  lcd.print(dmyhms[0] & 0x3F,HEX); // Days to LCD
  lcd.print("/");


  if(dmyhms[1] < 10)
    lcd.print('0');
    
  lcd.print(dmyhms[1] & 0x1F,HEX); // Months to LCD
  lcd.print("/");

  if(dmyhms[2] == 0xA0)
    dmyhms[2] = 0;
  if(dmyhms[2] < 10) 
    lcd.print('0');
    
  lcd.print(dmyhms[2],HEX); // Years to LCD    


}

//**********************************************************************
// My functions start right now.
//**********************************************************************
void RTC_init() 
{
  Wire.beginTransmission(RTC); // Open comm. with RTC
  Wire.write(0x00); // Set RTC address to be accessed
  // SEND 3 bytes to RTC to start clock ticking and set initial time and in the modes desired 
  // i.e. (continuous/one shot) or 12hr/24hr you will need to add more HEX bytes for calendar.
  Wire.write(0x45); // Seconds (this one is easy)
  Wire.write(0x59); // Minutes (...so is this one)
  //Wire.send(0x11); // Hours (also selects 24hr - bit6=0 (24hr) Wire.send() is no longer supported by the library
  // Wire.write(0x51); // 12hr mode in the AM (bit6=1 and bit5=0)
  Wire.write(0x71); // 12hr mode in the PM (bit6=1 and bit5=1)
  // Wire.write(0x11); // 24hr mode 11
  // Wire.write(0x23); //24 mode 23
                                                                                                                        // When in 12hr mode you must also write to bit5 => 0=am 1=pm
                                                                                                                        // Since in 12hr mode this bit is not needed for hours it is now the am/pm bit:
                                                                                                                        // Example 0x51 ==> 0 1 0 1 – 0 0 0 1
                                                                                                                        // – 12hr am 1 1 o'clock (am)
                                                                                                                        // Example 0x71 ==> 0 1 1 1 – 0 0 0 1
                                                                                                                        // – 12hr pm 1 1 o'clock (pm)
                                                                                                                        // Example 0x11 ==> 0 0 0 1 – 0 0 0 1
                                                                                                                        // – 24hr x 1 1 hundred hours
  Wire.write(0x05); //Date of the week
  Wire.write(0x31); //Day
  Wire.write(0x12); //Month
  Wire.write(0x99); //Year
  Wire.write(0x12); //Control

  Wire.endTransmission(); // Close I2C com. with RTC
}


//**********************************************************************
void RTC_read()
{
  Wire.beginTransmission(RTC); // Open comm. with RTC
  Wire.write(0x00);// SEND RTC address to be accessed
  Wire.endTransmission(); // Close I2C com. with RTC
  // Get current time from RTC by requesting 3 bytes (you will add more)
  Wire.requestFrom(RTC, 7); // Read in 3 BCD bytes from RTC
  dmyhms[5] = Wire.read() & 0x7F; // Store seconds
  dmyhms[4] = Wire.read() & 0x7F; // Store minutes
  dmyhms[3] = Wire.read() & 0x3F; // Store hours
  date = Wire.read() & 0x07;
  dmyhms[0] = Wire.read() & 0x3F; //days
  dmyhms[1] = Wire.read() & 0x1F; //months
  dmyhms[2] = Wire.read() & 0xFF; //years
}