/*
 *	lcd.c
 *  
 *	Uses routines from delay.c
 *
 *	This code will interface to a standard LCD controller
 *	like the Hitachi HD44780. It uses it in 4 bit mode, with
 *	the hardware connected as follows (the standard 14 pin 
 *	LCD connector is used):
 *	
 *	PORTB bits 0-3 are connected to the LCD data bits 4-7 (high nibble)
 *	PORTB bit 4 is connected to the LCD RS input (register select)
 *	PORTB bit 5 is connected to the R/!W 
 *
 *	PORTA bit 4 is connected to the LCD EN bit (enable)
 *  PORTA bit 5 is connected to the LCD backlight
 *	
 *	To use these routines, set up the port I/O (TRISA, TRISB) then
 *	call lcd_init(), then other routines as required.
 *
 *	Modified from the HITEC C sample programs to work with
 *  the Northmicro NM110 LCD board.	
 */

#include	<pic.h>
#include	"lcd.h"
#include	"delay.h"
 
#define LCD_RS RB4	//control/data mode
#define LCD_RW RB5	//read/!write 
#define LCD_EN RA4	//enable 
#define LCD_BL RA5	//backlight

#define nop asm("nop")
#define	LCD_STROBE	LCD_EN = 1; nop; 	LCD_EN = 0
#define LCD_PORTEN	TRISB = 0;	nop;	LCD_RW = 0	//LCD Port fix as LCD shares with keypad

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

void lcd_write(unsigned char c)
{
	PORTB = (PORTB & 0xF0) |  (c >> 4);		// send MSNibble
	LCD_STROBE;
	PORTB = (PORTB & 0xF0) |  (c & 0x0F);		// send LSNibble
	LCD_STROBE;
	DelayUs(80);
}


/* 	Clear and home the LCD */

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



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

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



/* write one character to the LCD */

void lcd_putch(char c)
{
	LCD_PORTEN;
	LCD_RS = 1;	// write characters
	PORTB = (PORTB & 0xF0) |  (c >> 4);		// send MSNibble
	LCD_STROBE;
	PORTB = (PORTB & 0xF0) |  (c & 0x0F);		// send LSNibble
	LCD_STROBE;
	DelayUs(80);
}



/* Go to the specified position */

void lcd_goto(unsigned char pos)
{
	LCD_PORTEN;
	LCD_RS = 0;
	lcd_write(0x80+pos);		//80 is goto command
}
	


/* control backlight */

void lcd_bl(char status)
{
	if(status)
		LCD_BL = 1; //turn backlight on
	else
		LCD_BL = 0;	//turn backlight off
}



/* initialise the LCD - put into 4 bit mode */

void lcd_init(void)
{
	LCD_EN = 0;		// setup lcd enable for strobe
	LCD_PORTEN;		// enable port and write mode
	LCD_RS = 0;		// clr to write control bytes
	DelayMs(30);	// power on delay

	lcd_write(0x30);
	DelayMs(5);

	lcd_write(0x30);
	DelayMs(5);

	lcd_write(0x30);
	DelayMs(5);

	lcd_write(0x20);
	DelayMs(5);

	lcd_write(0x28);	// 4 bit mode, 1/16 duty, 5x8 font
	lcd_write(0x0c);	// display on cursor off blink off
	lcd_clear();		
	lcd_write(0x06);	// entry mode set increment mode/ entire shift off

}