/*
From: "Ben Loveday" <lovedayben AT hotmail DOT com> (NOSPAM)
To: <paul@pjrc.com>
Subject: LCD code
Date: Sat, 22 Jun 2002 20:22:18 +1200

I havent had much time lately to work on my 8051 board but i have
completed some lcd routines that allow a 4x20 char lcd to run off the
ppi. I've attatched it so you can put it in the code section if you
like.

Cheers,
Ben Loveday


  Note from Paul: Ben's C code includes two files which appear to be
  the ones included in the LED Blink example, found at this page:
  http://www.pjrc.com/tech/8051/board3/blink_sdcc.html
*/





/* LCD.C - Lcd routines for the 8051 family microcontroller
 * Written by Ben Loveday
 * Thanks to Randy Rasa's parallel port lcd interface code.
 * Configured for use with Paul S 8051 development board
 * Set to use 4x20 char lcd, data lines on PA.0-PA.7
 * RS, R/W, and E on PB.5-PB.7 respectively
 */

#include "c:\sdcc\bin\delay_ms.h"
#include "c:\sdcc\bin\paulmon2.h"
#include <8051.h>

/* Function declarations */

void ppi_set_output(void);
void init_lcd(void);
void clear_lcd(void);
void write_control(unsigned char);
void write_data(unsigned char);
void lcd_cursor (char row, char column);
void lcd_displayscreen (char ptr);
void lcd_displayrow(char row, char *string);
void lcd_char(char input);

xdata at 0x4000 unsigned char lcd_data; //port_a;
xdata at 0x4001 unsigned char lcd_control; //port_b;
xdata at 0x4002 unsigned char port_c;
xdata at 0x4003 unsigned char config;

/* Configures the PPI for output */

void ppi_set_output()
{
    config = 128;	/* all ports outputs */
}

/* Writes given control to lcd */

void write_control(unsigned char contr)
{
    lcd_control = 0x00;    
    lcd_data = contr;	      	
    lcd_control = 0x80;    
    lcd_control = 0x00;    
    lcd_control = 0x40;
    delay_ms(5);   
}

/* Writes given data to lcd */

void write_lcd(unsigned char disp)
{
    lcd_control = 0x20;    
    lcd_data = disp;	      	
    lcd_control = 0xa0;  
    lcd_control = 0x20;    
    lcd_control = 0x60;
    delay_ms(5);
}

/* Initialises lcd */

void init_lcd()
{
    write_control(0x38);
    write_control(0x38);
    write_control(0x38);
    write_control(0x06);
    write_control(0x0d); 
}

/* Clears lcd */

void clear_lcd()
{
    write_control(0x01);
	delay_ms(5);
}

/* Sets current lcd cursor position */

void lcd_cursor (char row, char column)
{
  switch (row) {
    case 1: write_control(0x80 + column - 1); break;
    case 2: write_control(0xc0 + column - 1); break;
    case 3: write_control(0x94 + column - 1); break;
    case 4: write_control(0xd4 + column - 1); break;
    default: break;
  }
}

/* Displays entire screen on lcd ( takes an 80 char string )*/

void lcd_displayscreen (char ptr)
{
  lcd_displayrow(1,ptr+ 0);
  lcd_displayrow(2,ptr+20);
  lcd_displayrow(3,ptr+40);
  lcd_displayrow(4,ptr+60);
}

/* Displays a character at the current cursor position */

void lcd_char(char input)
{
	char input2;
	input2 = (int)input;
	write_lcd(input2);
}

/* Displays entire row of text from current cursor position */

void lcd_displayrow(char row, char *string)
{
  char i;
 
  lcd_cursor(row, 1);
  for (i=0; i<19; i++)
	  
    lcd_char(*string++);
}