/* io.c
 *
 * Copyright (c) 2003-2004 Susan Cotterell.
 * Permission to copy is granted provided that this header remains
 * intact. This software is provided with no warranties.
 *
 * Version : 1.0
 *
 * 4-Bit LCD Interface
 *
 */

/*-------------------------------------------------------------------------*/

#include <pic.h>
#include "io.h"
#include "delay.h"

/*-------------------------------------------------------------------------*/

#define DATA_BUS PORTB
#define RS       RA2
#define E        RA3
#define RS_BIT   2
#define E_BIT    3

/*-------------------------------------------------------------------------*/

unsigned char tempA = 0x00;

/*-------------------------------------------------------------------------*/

void EnableLCD(void) {

    bitclr(tempA, PORTA, RS_BIT); DelayUs(1); //RS = 0
    bitset(tempA, PORTA, E_BIT); DelayUs(1);  //E = 1
    bitclr(tempA, PORTA, E_BIT); DelayUs(1);  //E = 0
}

/*-------------------------------------------------------------------------*/

void EnableLCD2(void) {

    bitset(tempA, PORTA, RS_BIT); DelayUs(1);
    bitset(tempA, PORTA, E_BIT);  DelayUs(1);
    bitclr(tempA, PORTA, E_BIT);  DelayUs(1);
}

/*-------------------------------------------------------------------------*/

void InitIO(void) {

    DATA_BUS = (DATA_BUS & 0x0F) | 0x30; EnableLCD();
    DATA_BUS = (DATA_BUS & 0x0F) | 0x30; EnableLCD();
    DelayMs(5);
               
    DATA_BUS = (DATA_BUS & 0x0F) | 0x30; EnableLCD();
    DATA_BUS = (DATA_BUS & 0x0F) | 0x20; EnableLCD();    // set 4-bit interface
    DelayUs(100);

    DATA_BUS = (DATA_BUS & 0x0F) | 0x20; EnableLCD();    // FUNCTION SET
    DATA_BUS = (DATA_BUS & 0x0F) | 0x80; EnableLCD();    // FUNCTION SET
    DelayUs(100);

    DATA_BUS = (DATA_BUS & 0x0F) | 0x00; EnableLCD();    // DISPLAY OFF
    DATA_BUS = (DATA_BUS & 0x0F) | 0x80; EnableLCD();    // DISPLAY OFF
    DelayUs(100);

    DATA_BUS = (DATA_BUS & 0x0F) | 0x00; EnableLCD();    // CLEAR SCREEN
    DATA_BUS = (DATA_BUS & 0x0F) | 0x10; EnableLCD();    // CLEAR SCREEN
    DelayMs(2);
    
    DATA_BUS = (DATA_BUS & 0x0F) | 0x00; EnableLCD();    // ENTRY MODE SET
    DATA_BUS = (DATA_BUS & 0x0F) | 0x60; EnableLCD();    // ENTRY MODE SET
    DelayUs(40);

    DATA_BUS = (DATA_BUS & 0x0F) | 0x00; EnableLCD();    // DISPLAY ON
    DATA_BUS = (DATA_BUS & 0x0F) | 0xD0; EnableLCD();    // DISPLAY ON
    DelayUs(40);
}

/*-------------------------------------------------------------------------*/

void ClearScreen(void) {

    DATA_BUS= (DATA_BUS & 0x0F) | 0x00; EnableLCD();    // CLEAR SCREEN
    DATA_BUS= (DATA_BUS & 0x0F) | 0x10; EnableLCD();    // CLEAR SCREEN
    DelayMs(2);
}

/*-------------------------------------------------------------------------*/

void GotoXY(unsigned char r, unsigned char c) {

    DATA_BUS= (DATA_BUS & 0x0F) | 0x00; EnableLCD(); 
    DATA_BUS= (DATA_BUS & 0x0F) | 0x20; EnableLCD();            
    DelayMs(2);    

    for(r=r*40+c, c=0; c<r; c++){
		DATA_BUS= (DATA_BUS & 0x0F) | 0x10; EnableLCD();  
        DATA_BUS= (DATA_BUS & 0x0F) | 0x40; EnableLCD();       
	   	DelayUs(40);    
    }
}

/*-------------------------------------------------------------------------*/

void PutChar(char c) {

   DATA_BUS= (DATA_BUS & 0x0F) | (c & 0xF0); EnableLCD2();   
   DATA_BUS= (DATA_BUS & 0x0F) | ((c & 0X0F) << 4); EnableLCD2();
   DelayUs(40);    
}

/*-------------------------------------------------------------------------*/

void PrintString(const char* s) {

   while( *s )PutChar(*(s++));  
}