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/*********************************************************************

*

*       LCD Access Routines

*

*********************************************************************

* FileName:        LCDBlocking.c

* Dependencies:    Compiler.h

* Processor:       PIC24F

* Complier:        MCC30 v2.01 or higher

* Company:         Microchip Technology, Inc.

*

* Software License Agreement

*

 * This software is owned by Microchip Technology Inc. ("Microchip")

 * and is supplied to you for use exclusively as described in the

 * associated software agreement.  This software is protected by

 * software and other intellectual property laws.  Any use in

 * violation of the software license may subject the user to criminal

 * sanctions as well as civil liability.  Copyright 2006 Microchip

 * Technology Inc.  All rights reserved.

 *

 * This software is provided "AS IS."  MICROCHIP DISCLAIMS ALL

 * WARRANTIES, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, NOT LIMITED

 * TO MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND

 * INFRINGEMENT.  Microchip shall in no event be liable for special,

 * incidental, or consequential damages.

*

*

* Author               Date         Comment

*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Howard Schlunder     4/03/06      Original

* Howard Schlunder     4/12/06      Changed from using PMP to LCDWrite()

* Howard Schlunder     8/10/06      Fixed a delay being too short

*                                   when CLOCK_FREQ was a smaller

*                                   value, added FOUR_BIT_MODE

********************************************************************/

#include "..\Include\StackTsk.h"

#include "..\Include\Compiler.h"

#include "..\Include\Delay.h"

// Do not include this source file if there is no LCD on the 

// target board

#ifdef USE_LCD

#if defined(PICDEMNET)

#define FOUR_BIT_MODE

#endif

// LCDText is a 32 byte shadow of the LCD text.  Write to it and 

// then call LCDUpdate() to copy the string into the LCD module.

BYTE LCDText[16*2+1];

/******************************************************************************

 * Function:        static void LCDWrite(BYTE RS, BYTE Data)

 *

 * PreCondition:    None

 *

 * Input:           RS - Register Select - 1:RAM, 0:Config registers

 *                  Data - 8 bits of data to write

 *

 * Output:          None

 *

 * Side Effects:    None

 *

 * Overview:        Controls the Port I/O pins to cause an LCD write

 *

 * Note:            None

 *****************************************************************************/

static void LCDWrite(BYTE RS, BYTE Data)

{

    LCD_DATA_TRIS = 0x00;

    LCD_RS_TRIS = 0;

    LCD_RD_WR_TRIS = 0;

    LCD_RD_WR_IO = 0;

    LCD_RS_IO = RS;

#if defined(FOUR_BIT_MODE)

    LCD_DATA_IO = Data>>4;

    Nop();                  // Wait Data setup time (min 40ns)

    Nop();

    LCD_E_IO = 1;

    Nop();                  // Wait E Pulse width time (min 230ns)

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    LCD_E_IO = 0;

#endif

    LCD_DATA_IO = Data;

    Nop();                  // Wait Data setup time (min 40ns)

    Nop();

    LCD_E_IO = 1;

    Nop();                  // Wait E Pulse width time (min 230ns)

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    Nop();

    LCD_E_IO = 0;

    LCD_DATA_TRIS = 0xFF;

    LCD_RS_TRIS = 1;

    LCD_RD_WR_TRIS = 1;

}

/******************************************************************************

 * Function:        void LCDInit(void)

 *

 * PreCondition:    None

 *

 * Input:           None

 *

 * Output:          None

 *

 * Side Effects:    None

 *

 * Overview:        LCDText[] is blanked, port I/O pin TRIS registers are

 *                  configured, and the LCD is placed in the default state

 *

 * Note:            None

 *****************************************************************************/

void LCDInit(void)

{

    BYTE i;

    for(i = 0; i < sizeof(LCDText)-1; i++)

    {

        LCDText[i] = ' ';

    }

    LCDText[sizeof(LCDText)-1] = 0;

    // Setup the I/O pins

    LCD_E_IO = 0;

    LCD_RD_WR_IO = 0;

    LCD_DATA_TRIS = 0x00;

    LCD_RD_WR_TRIS = 0;

    LCD_RS_TRIS = 0;

    LCD_E_TRIS = 0;

    // Wait the required time for the LCD to reset

    DelayMs(30);

    // Set the default function

#if defined(FOUR_BIT_MODE)

    LCDWrite(0, 0b00101000);

#else

    LCDWrite(0, 0b00111000);

#endif

    Delay10us(5);

    // Set the display control

    LCDWrite(0, 0b00001100);

    Delay10us(5);

    // Clear the display

    LCDWrite(0, 0b00000001);

    Delay10us(153);

    // Set the entry mode

    LCDWrite(0, 0b00000110);

    Delay10us(5);

}

/******************************************************************************

 * Function:        void LCDUpdate(void)

 *

 * PreCondition:    LCDInit() must have been called once

 *

 * Input:           LCDText[]

 *

 * Output:          None

 *

 * Side Effects:    None

 *

 * Overview:        Copies the contents of the local LCDText[] array into the

 *                  LCD's internal display buffer.  Null terminators in

 *                  LCDText[] terminate the current line, so strings may be

 *                  printed directly to LCDText[].

 *

 * Note:            None

 *****************************************************************************/

void LCDUpdate(void)

{

    BYTE i, j;

    // Go home

    LCDWrite(0, 0b00000010);

    DelayMs(1);

    Delay10us(53);

    // Output first line

    for(i = 0; i < 16; i++)

    {

        // Erase the rest of the line if a null char is 

        // encountered (good for printing strings directly)

        if(LCDText[i] == 0)

        {

            for(j=i; j < 16; j++)

            {

                LCDText[j] = ' ';

            }

        }

        LCDWrite(1, LCDText[i]);

        Delay10us(5);

    }

    // Set the address to the second line

    LCDWrite(0, 0xC0);

    Delay10us(5);

    // Output second line

    for(i = 16; i < 32; i++)

    {

        // Erase the rest of the line if a null char is 

        // encountered (good for printing strings directly)

        if(LCDText[i] == 0)

        {

            for(j=i; j < 32; j++)

            {

                LCDText[j] = ' ';

            }

        }

        LCDWrite(1, LCDText[i]);

        Delay10us(5);

    }

}

/******************************************************************************

 * Function:        void LCDErase(void)

 *

 * PreCondition:    LCDInit() must have been called once

 *

 * Input:           None

 *

 * Output:          None

 *

 * Side Effects:    None

 *

 * Overview:        Clears LCDText[] and the LCD's internal display buffer

 *

 * Note:            None

 *****************************************************************************/

void LCDErase(void)

{

    // Clear display

    LCDWrite(0, 0b00000001);

    Delay10us(153);

    // Clear local copy

    memset(LCDText, ' ', 32);

}

#endif  //#ifdef USE_LCD