#include <msp430x16x.h>
#include <stdio.h>

unsigned int i = 0;
unsigned char second;
unsigned char minute;
unsigned char hour;
unsigned char day;
unsigned char date;
unsigned char month;
unsigned char year;

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                         // Stop watchdog
  P3SEL |= 0x0a;                                    // Assign I2C pins to module
  U0CTL |= I2C + SYNC;                              // Switch USART0 to I2C mode (Reccommended I2C init procedure)
  U0CTL &= ~I2CEN;                                  // Disable the I2C module (Recommended I2C init procedure)
  
  // Now configure I2C Module with I2CEN  = 0
  
  I2CTCTL |= I2CSSEL_1;                             // ACLK
  I2CSCLH = 0x00;                                   // High period of SCL
  I2CSCLL = 0x00;                                   // Low period of SCL
  I2CNDAT = 0x08;                                   // Send 8 bytes (byte = 8 bits) 
  I2CSA = 0x0068;                                   // Slave address is 0x68
  
  // Now enable I2C Module

  U0CTL |= I2CEN;                                   // Enable I2C using a 7-bit address
  
  //Now set time
  
  U0CTL |= MST;                                 // Master mode
  I2CTCTL |= I2CTRX + I2CSTT + I2CSTP;          // Transmit, ST, SP (clears MST)
  while ((I2CIFG & ARDYIFG) != ARDYIFG)         // Check if all data has been sent
  {
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x00;                            // Set register pointer to seconds
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x00;                            // Set seconds
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x19;                            // Set minutes
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x05;                            // Set hours
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x00;                            // Set day
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x20;                            // Set date
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x05;                            // Set month
        while (( I2CIFG & TXRDYIFG) != TXRDYIFG)   // Do nothing if I2C is not ready for new transmit data
    {
    }
        I2CDRB = 0x07;                            // Set year
        I2CIFG |= ARDYIFG;                        // All data has been sent
  }

  U0CTL &= ~I2CEN;                                  // Disable the I2C module (Recommended I2C init procedure)
  I2CNDAT = 0x01;                                   // Write 1 byte (byte = 8 bits)
  U0CTL |= I2CEN;                                   // Enable I2C using a 7-bit address
  
  while (1)
  {
    U0CTL |= MST;                                 // Master mode
    I2CTCTL |= I2CTRX + I2CSTT + I2CSTP;          // Transmit, ST, SP (clears MST)
    while ((I2CIFG & ARDYIFG) != ARDYIFG)         // Check if all data has been sent
    {
      while (( I2CIFG & TXRDYIFG) != TXRDYIFG)      // Do nothing if I2C is not ready to transmit data
      {
      }
      I2CDRB = 0x00;                                // Reset register pointer to read seconds first
      I2CIFG |= ARDYIFG;                            // All data has been read
      }
    while ((I2CDCTL & I2CBUSY) == I2CBUSY)          // If I2C is still busy do nothing
    {
    }
    while ( i < 7)
    {
      I2CIFG &= ~ARDYIFG;                           // Reset ARDYIFG bit
      I2CTCTL &= ~I2CTRX;                           // Reset I2CTRX bit
      U0CTL |= MST;                                 // Master mode
      I2CTCTL |= I2CSTT + I2CSTP;                   // Read, ST, SP (clears MST)
      while ((I2CIFG & ARDYIFG) != ARDYIFG)         // Check if all data has been read
      {
        while (( I2CIFG & RXRDYIFG) != RXRDYIFG)      // Do nothing if I2C is not ready to read data
        {
        }
        switch (i)
		{
		case 0:
			second = I2CDRB;
                        I2CIFG |= ARDYIFG;
			break;
		case 1:
			minute = I2CDRB;
                        I2CIFG |= ARDYIFG;
			break;
		case 2:
			hour = I2CDRB;
                        I2CIFG |= ARDYIFG;
			break;
		case 3:
			day = I2CDRB;
                        I2CIFG |= ARDYIFG;
			break;
		case 4:
			date = I2CDRB;
                        I2CIFG |= ARDYIFG;
			break;
		case 5:
			month = I2CDRB;
                        I2CIFG |= ARDYIFG;
			break;
		case 6:
			year = I2CDRB;
                        I2CIFG |= ARDYIFG;
			break;
		}
        i++;
      }
    }
    i = 0;
    printf ("%x/", day);
	printf ("%x/", date);
	printf ("200%x ", year);
	printf ("%x:", hour);
	printf ("%x:", minute);
	printf ("%x\n", second);
    I2CIFG &= ~ARDYIFG;                           // Reset ARDYIFG bit
  }
}