#include <htc.h>
#define _XTAL_FREQ 4000000
#include   "lcd.h"

#define   LCD_RS RE2
#define   LCD_RW RE1
#define LCD_EN RE0

#define LCD_DATA   PORTA

#define   LCD_STROBE()   ((LCD_EN = 1),(LCD_EN=0))

/* write a byte to the LCD in 4 bit mode */

void
lcd_write(unsigned char c)
{
   __delay_us(40);
   LCD_DATA = ( ( c >> 4 ) & 0x0F );
   LCD_STROBE();
   LCD_DATA = ( c & 0x0F );
   LCD_STROBE();
}

/*
 *    Clear and home the LCD
 */

void
lcd_clear(void)
{
   LCD_RS = 0;
   lcd_write(0x1);
   __delay_ms(2);
}

/* write a string of chars to the LCD */

void
lcd_puts(const char * s)
{
   LCD_RS = 1;   // write characters
   while(*s)
      lcd_write(*s++);
}

/* write one character to the LCD */

void
lcd_putch(char c)
{
   LCD_RS = 1;   // write characters
   lcd_write( c );
}


/*
 * Go to the specified position
 */

void
lcd_goto(unsigned char pos)
{
   LCD_RS = 0;
   lcd_write(0x80+pos);
}
   
/* initialise the LCD - put into 4 bit mode */
void
lcd_init()
{
   char init_value;

   ADCON1 = 0x06;   // Disable analog pins on PORTA

   init_value = 0x3;
   TRISA0=0;
   TRISA1=0;
   TRISA2=0;
   TRISA3=0;
   TRISE0=0;
   TRISE1=0;
   TRISE2=0;
   LCD_RS = 0;
   LCD_EN = 0;
   LCD_RW = 0;
   
   __delay_ms(15);   // wait 15mSec after power applied,
   LCD_DATA    = init_value;
   LCD_STROBE();
   __delay_ms(5);
   LCD_STROBE();
   __delay_us(200);
   LCD_STROBE();
   __delay_us(200);
   LCD_DATA = 2;   // Four bit mode
   LCD_STROBE();

   lcd_write(0x28); // Set interface length
   lcd_write(0xC); // Display On
   lcd_clear();   // Clear screen
   lcd_write(0x6); // Set entry Mode
}