// 16x2 HD44780 based LCD Module functions for SDCC / P89V51RD2

/* Original Code by:
 * Author   : sci-3d@hotmail.com
 * Date		: 2006-08-01 (yyyy-mm-dd)
 */
 
/* Modified for ucmicrosys UNI-51-SDK (www.ucmicrosys.com) by
 * Author(s)	: Anurag Chugh (anurag@ucmicrosys.com) and Ranjit Puri (ranjit.puri@gmail.com)
 * Date		: 2006-12-15 (yyyy-mm-dd)
 */

//NOTES:
//1: This code may be distributed and modified freely .
//2: External Crystal of 11.0592 MHz is assumed.
//3. 16x2 LCD Modules is being operated in Nibble Mode.
//4: Connections to the LCD are assumed as followed:
//		RS		-> P0.0
//		RW		-> P0.1	
//		E		-> P0.2
//		D4,D5,D6,D7	-> P0.4,P0.5,P0.6,P0.7

#ifndef __p89v51rd2_h__
	#include <p89v51rd2.h>
	#define __p89v51rd2_h__
#endif


#define LCD_DATA P0
#define LCD_en P0_2
#define LCD_rs P0_0 
#define LCD_rw P0_1  			//Must Always be low to allow data to be sent to LCD
#define LCD_DELAY 100 			//Delay for allowing the LCD to execute the Command Sent to it
#define LCD_clear() LCD_command(0x1)	//Clear display LCD
#define LCD_origin() LCD_command(0x2)	//Set to origin LCD
#define LCD_row1() LCD_command(0x80)	//Begin at Line 1
#define LCD_row2() LCD_command(0xC0)   //Begin at Line 2
 

void LCD_gotoxy(char position, char line);
void LCD_delay(unsigned char ms);
void LCD_enable();
void LCD_command(unsigned char command);
void LCD_putc(unsigned char ascii);
void LCD_puts(unsigned char *lcd_string);	//Function to put a string on LCD
void LCD_init();				//Function to initialize the LCD module

void LCD_delay(unsigned char ms)
{
	unsigned char n;
	unsigned int i;
	for (n=0; n<ms; n++)
	{
		for (i=0; i<LCD_DELAY; i++);
	}
    
}

void LCD_enable()
{
	LCD_en = 0;		//High to low transition
	LCD_delay(1);
	LCD_en = 1;		//Back to default state
}

void LCD_command(unsigned char command)
{
    LCD_rs = 0;			//Command Mode
    LCD_DATA = ((command & 0xF0)|0x04);
    LCD_enable();
    LCD_DATA = (((command<<4) & 0xF0)|0x04);
    LCD_enable();
    LCD_delay(1);
}

void LCD_putc(unsigned char ascii)
{
    LCD_rs = 1;			//Data Mode
    LCD_DATA = ((ascii & 0xF0)|0x05);
    LCD_enable();
    LCD_DATA = (((ascii<<4) & 0xF0)|0x05);
    LCD_enable();
    LCD_delay(1);
}

void LCD_puts(unsigned char *lcd_string)
{
	while (*lcd_string) 
	{
		LCD_putc(*lcd_string++);
	}
}

void LCD_init()
{
	LCD_delay(20);		//Let LCD Driver stabilize
	P0=0x00;
	LCD_en = 1;
	LCD_rs = 0;
	LCD_rw = 0; 
	LCD_command(0x33);	//8 bit mode, 8 bit mode
	LCD_command(0x33);	//8 bit mode, 8 bit mode
	LCD_command(0x32);	//8 bit mode, 4 bit mode
	LCD_command(0x28);	//4 bit mode, 2 line mode
	LCD_command(0x0F);	//Display Cursor (Underline and Blink)
	LCD_command(0x03);	//Display and Cursor Home
	LCD_delay(20);		//Display and Cursor Home requres more time
	LCD_command(0x01);	//Clear Display
	LCD_delay(20);		//Clear Display requires more time
}

void LCD_gotoxy(char position, char line)
{
	if(line == 0)
	{
		LCD_command(0x80 + position);
	}
	else if(line == 1)
	{
		LCD_command(0x80 + 0x40 + position);
	}
}