// LCD module connections
sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;
sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections
// Global date/time variables
char seconds, minutes, hours, day, month, year; 
//----- Reads time and date information from RTC (DS1307)
void Read_Time() {
  I2C1_Start();                // Issue start signal
  I2C1_Wr(0xD0);             // Address DS1307, see DS1307 datasheet
  I2C1_Wr(0);                // Start from address 0>> SEC
  
  I2C1_Repeated_Start();      // issue I2C signal repeated start
  I2C1_Wr(0xD1);             // Address DS1307 for reading R/W=1
  seconds = I2C1_Rd(1);      // Read seconds byte
  minutes = I2C1_Rd(1);      // Read minutes byte
  hours = I2C1_Rd(1);        // Read hours byte
  day = I2C1_Rd(1);          // Read year/day byte
  month = I2C1_Rd(0);        // Read weekday/month byte
  I2C1_Stop();                 // Issue stop signal
 }
//-------------------- Formats date and time
void Transform_Time() {
  seconds  =  ((seconds & 0xF0) >> 4)*10 + (seconds & 0x0F);  // Transform seconds
  minutes  =  ((minutes & 0xF0) >> 4)*10 + (minutes & 0x0F);  // Transform months
  hours    =  ((hours & 0xF0)  >> 4)*10  + (hours & 0x0F);    // Transform hours
  year     =   (day & 0xC0) >> 6;                             // Transform year
  day      =  ((day & 0x30) >> 4)*10    + (day & 0x0F);       // Transform day
  month    =  ((month & 0x10)  >> 4)*10 + (month & 0x0F);     // Transform month
}
//-------------------- Output values to LCD
void Display_Time() {
   Lcd_Chr(1, 6, (day / 10)   + 48);    // Print tens digit of day variable
   Lcd_Chr(1, 7, (day % 10)   + 48);    // Print oness digit of day variable
   Lcd_Chr(1, 9, (month / 10) + 48);
   Lcd_Chr(1,10, (month % 10) + 48);
   Lcd_Chr(1,15,  year        + 48);    // Print year variable  (start from year 2010)
   Lcd_Chr(2, 6, (hours / 10)   + 48);
   Lcd_Chr(2, 7, (hours % 10)   + 48);
   Lcd_Chr(2, 9, (minutes / 10) + 48);
   Lcd_Chr(2,10, (minutes % 10) + 48);
   Lcd_Chr(2,12, (seconds / 10) + 48);
   Lcd_Chr(2,13, (seconds % 10) + 48);
}
//------------------ Performs project-wide init
void Init_Main() {
  TRISB = 0;
  PORTB = 0xFF;
  TRISB = 0xff;
  //ANSEL  = 0;                // Configure AN pins as digital I/O
  //ANSELH = 0;
  //C1ON_bit = 0;              // Disable comparators
  //C2ON_bit = 0;
  I2C1_Init(100000);         // initialize I2C communication
  Lcd_Init();                // Initialize LCD
  Lcd_Cmd(_LCD_CLEAR);       // Clear LCD display
  Lcd_Cmd(_LCD_CURSOR_OFF);  // Turn cursor off
  Lcd_Out(1,1,"Date:");      // Prepare and output static text on LCD
  Lcd_Chr(1,8,'.');
  Lcd_Chr(1,11,'.');
  Lcd_Chr(1,16,'.');
  Lcd_Out(2,1,"Time:");
  Lcd_Chr(2,8,':');
  Lcd_Chr(2,11,':');
  Lcd_Out(1,12,"201");       // start from year 2010
}
//----------------- Main procedure
void main() {
  Delay_ms(500);
  Init_Main();               // Perform initialization
  while (1) {                // Endless loop
    Read_Time();             // Read time from RTC(PCF8583)
    Transform_Time();        // Format date and time
    Display_Time();          // Prepare and display on LCD
  }
}