////////////////////////////////////////////////////////////////////////////
////                             LCDD.C                                 ////
////                 Driver for common LCD modules                      ////
////                                                                    ////
////  lcd_init()   Must be called before any other function.            ////
////                                                                    ////
////  lcd_putc(c)  Will display c on the next position of the LCD.      ////
////                     The following have special meaning:            ////
////                      \f  Clear display                             ////
////                      \n  Go to start of second line                ////
////                      \b  Move back one position                    ////
////                                                                    ////
////  lcd_gotoxy(x,y) Set write position on LCD (upper left is 1,1)     ////
////                                                                    ////
////  lcd_getc(x,y)   Returns character at position x,y on LCD          ////
////                                                                    ////
////////////////////////////////////////////////////////////////////////////
////        (C) Copyright 1996,1997 Custom Computer Services            ////
//// This source code may only be used by licensed users of the CCS C   ////
//// compiler.  This source code may only be distributed to other       ////
//// licensed users of the CCS C compiler.  No other use, reproduction  ////
//// or distribution is permitted without written permission.           ////
//// Derivative programs created using this software in object code     ////
//// form are not restricted in any way.                                ////
////////////////////////////////////////////////////////////////////////////

// As defined in the following structure the pin connection is as follows:
//     D0  enable
//     D1  rs
//     D2  rw
//     D4  D4
//     D5  D5
//     D6  D6
//     D7  D7
//
//   LCD pins D0-D3 are not used and PIC D3 is not used.

// Un-comment the following define to use port B
// #define use_portb_lcd TRUE


struct lcd_pin_map {                 // This structure is overlayed
           boolean enable;           // on to an I/O port to gain
           boolean rs;               // access to the LCD pins.
           boolean rw;               // The bits are allocated from
           boolean unused;           // low order up.  ENABLE will
           int     data : 4;         // be pin B0.
        } lcd;



#if defined(__PCH__)
#if defined use_portb_lcd
   #byte lcd = 0xF81                   // This puts the entire structure
#else
   #byte lcd = 0xF83                   // This puts the entire structure
#endif
#else
#if defined use_portb_lcd
   #byte lcd = 6                  // on to port B (at address 6)
#else
   #byte lcd = 8                 // on to port D (at address 8)
#endif
#endif

#if defined use_portb_lcd
   #define set_tris_lcd(x) set_tris_b(x)
#else
   #define set_tris_lcd(x) set_tris_d(x)
#endif



#define lcd_type 2           // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_one 0x00    // LCD RAM address for the second line
#define lcd_line_two 0x40    // LCD RAM address for the second line
#define lcd_line_three 0x14    // LCD RAM address for the second line
#define lcd_line_four 0x54    // LCD RAM address for the second line
#define lcd_line_five 0xc0    // LCD RAM address for the second line
byte CONST LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 0xf, 6};
                             // These bytes need to be sent to the LCD
                             // to start it up.


                             // The following are used for setting
                             // the I/O port direction register.

STRUCT lcd_pin_map const LCD_WRITE = {0,0,0,0,0}; // For write mode all pins are out
STRUCT lcd_pin_map const LCD_READ = {0,0,0,0,15}; // For read mode data pins are in




byte lcd_read_byte() {
      byte low,high;
      set_tris_lcd(LCD_READ);
      lcd.rw = 1;
      delay_us(10);
      lcd.enable = 1;
      delay_us(10);
      high = lcd.data;
      lcd.enable = 0;
      delay_us(10);
      lcd.enable = 1;
      delay_us(1);
      low = lcd.data;
      lcd.enable = 0;
      set_tris_lcd(LCD_WRITE);
      return( (high<<4) | low);
}


void lcd_send_nibble( byte n ) {
      lcd.data = n;
      delay_us(10);
      lcd.enable = 1;
      delay_us(10);
      lcd.enable = 0;
}


void lcd_send_byte( byte address, byte n ) {

      lcd.rs = 0;
      while ( bit_test(lcd_read_byte(),7) ) ;
      delay_us(100);
      lcd.rs = address;
      delay_us(50);
      lcd.rw = 0;
      delay_us(50);
      lcd.enable = 0;
      lcd_send_nibble(n >> 4);
      lcd_send_nibble(n & 0xf);
}


void lcd_init() {
    byte i;
    set_tris_lcd(LCD_WRITE);
    lcd.rs = 0;
    lcd.rw = 0;
    lcd.enable = 0;
    delay_ms(15);
      for(i=1;i<=3;++i) {
       lcd_send_nibble(3);
       delay_ms(5);
    }
    lcd_send_nibble(2);
    for(i=0;i<=3;++i)
       lcd_send_byte(0,LCD_INIT_STRING[i]);
}


void lcd_gotoxy( byte x, byte y) {
   byte address;

   if(x==1)
   {
    address=lcd_line_one;
      address+=y;
        lcd_send_byte(0,0x80|address);
   }
   else if(x==2)
   {
     address=lcd_line_two;
       address+=y;
        lcd_send_byte(0,0x80|address);
   }
   else if(x==3)
   {
     address=lcd_line_three;
       address+=y;
        lcd_send_byte(0,0x80|address);
   }
   else if(x==4)
   {
     address=lcd_line_four;
       address+=y;
        lcd_send_byte(0,0x80|address);
   }
   else if(x==5)// define for lcd  1 line page2 8 to 16
   {
     address=lcd_line_five;
       address+=y;
        lcd_send_byte(0,0x80|address);
   }
   else{}
     //address=0;
   //address+=y;
   //lcd_send_byte(0,0x80|address);
}

void lcd_putc( char c) {
   switch (c) {
     case '\f'   : lcd_send_byte(0,1);
                   delay_ms(2);
                                           break;
     case '\n'   : lcd_gotoxy(1,2);        break;
     case '\b'   : lcd_send_byte(0,0x10);  break;
     default     : lcd_send_byte(1,c);     break;
   }
}

char lcd_getc( byte x, byte y) {
   char value;

    lcd_gotoxy(x,y);
    lcd.rs=1;
    value = lcd_read_byte();
    lcd.rs=0;
    return(value);
}