/*------------------------------------------------------------------------------
upsd3200_lcd.c

Version:
September 2004 Version 2.0 -
Updated the include file names and modified comments.  Added support for 
the Raisonance compiler.  Corrected the printfLCD() for the "w" format.  Removed
functions not typically used with the basic demos.


Dependencies:
upsd3200_timer.c - needed for delays used in functions that write data to the LCD.

Description:
The uPSD3200 LCD device driver is intended to provide a standard programmed 
I/O set of functions for driving a 16 x 2 line dot matrix LCD module that
is part of the DK3200 boards.  See the functions below for their description.


Copyright (c) 2004 STMicroelectronics Inc.

This example demo code is provided as is and has no warranty,
implied or otherwise.  You are free to use/modify any of the provided
code at your own risk in your applications with the expressed limitation
of liability (see below) so long as your product using the code contains
at least one uPSD product (device).

LIMITATION OF LIABILITY:   NEITHER STMicroelectronics NOR ITS VENDORS OR 
AGENTS SHALL BE LIABLE FOR ANY LOSS OF PROFITS, LOSS OF USE, LOSS OF DATA,
INTERRUPTION OF BUSINESS, NOR FOR INDIRECT, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES OF ANY KIND WHETHER UNDER THIS AGREEMENT OR
OTHERWISE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
------------------------------------------------------------------------------*/

#include "upsd3200.h"
#include "upsd3200_hardware.h"
#include "upsd3200_lcd.h"
#include "upsd3200_timer.h"

#ifdef __RC51__	     // If Raisonance compiler, need this include file for the 
                       //  printfLCD() function.
#include "stdarg.h"
#endif


typedef struct LCD_display_st {
	unsigned char LCD_CMD_WR;        // LCD_BASE+0x00
	unsigned char LCD_CMD_RD;        //         +0x01
   	unsigned char LCD_RAM_WR;     //         +0x02
   	unsigned char LCD_RAM_RD;     //         +0x03  
}  LCD_DISPLAY;

// XDATA address for display 
xdata LCD_DISPLAY LCD_reg _at_ LCD_BASE_ADDR;

static unsigned char Cursor_LCD;
static char orig_buscon;


/*------------------------------------------------------------------------------
lcd_init()

This function is used to initialize the LCD module per the specs.
------------------------------------------------------------------------------*/
void lcd_init(void)
{
   delay_10ms();
   LCD_reg.LCD_CMD_WR = 0x30;
   delay_10ms();		
   LCD_reg.LCD_CMD_WR = 0x30;
   delay_10ms();		
   LCD_reg.LCD_CMD_WR = 0x30;
   delay_10ms();		

   LCD_reg.LCD_CMD_WR = 0x38;	// 8 bits, 2 lines, 5 x 7 font   
   delay_10ms();              // delay 10 ms   
   BusyCheck();
   LCD_reg.LCD_CMD_WR = 0x0C;	//Display on, Cursor off, Non-Blink
   BusyCheck();
   LCD_reg.LCD_CMD_WR = 0x01;	//Clear display
   BusyCheck();
   LCD_reg.LCD_CMD_WR = 0x02;	//Cursor home
   BusyCheck();
   LCD_reg.LCD_CMD_WR = 0x06;	//Cursor inc, no shift/cursor move
 		
   Cursor_LCD = DD_ADDR;		//Display from 1st row, 1st column
   BusyCheck();
   LCD_reg.LCD_CMD_WR = Cursor_LCD;
   BusyCheck();
}

/*------------------------------------------------------------------------------
BusyCheck()

This function is used to wait until the LCD module's busy flag (BF) is cleared.
------------------------------------------------------------------------------*/
void BusyCheck(void)
	{
  	  unsigned char i;
	  while (LCD_reg.LCD_CMD_RD & BF_BIT);  // Loop while busy
	}


/*------------------------------------------------------------------------------
printfLCD(chr_ptr) 

This function is used to display a string of characters on the LCD display.

chr_ptr - unsigned char*
		- pointer to string to display on LCD.
------------------------------------------------------------------------------*/
void printfLCD(unsigned char *chr_ptr, ...) {

	unsigned char var;
    #ifdef __RC51__	// If Raisonance compiler, use ANSI stdarg
          va_list var_ptr;
	    va_start(var_ptr,0);
    #else	
        unsigned char *var_ptr=&chr_ptr+1;
    #endif

	while (*chr_ptr != NULL) {
		
 		BusyCheck();
		
 		if (*chr_ptr == '\r') {
 			chr_ptr++;
  			Cursor_LCD &= 0xC0;    				//return to position 0 at current line
			LCD_reg.LCD_CMD_WR = Cursor_LCD;
		}
		else
		if (*chr_ptr == '\n') {
 			chr_ptr++;
  			Cursor_LCD ^= 0x40;     			//goto next line
  			Cursor_LCD &= 0xC0;     			//return to position 0
			LCD_reg.LCD_CMD_WR = Cursor_LCD;
		}
 		else
		if (*chr_ptr == '%') {
 			chr_ptr++;
 			if (*chr_ptr == 'd') {			// display 1 digit decimal 0-9
				chr_ptr++;

  					var = *var_ptr++;
					LCD_reg.LCD_RAM_WR = (var & 0x0F)+'0';
  	   		}
  	    		else
  	    		if (*chr_ptr == 'x') {           	// display 1 byte hex 00-FF
				chr_ptr++;

  	    			var = *var_ptr++;
  	    			LCD_reg.LCD_RAM_WR = htoa_hi(var);
               BusyCheck();
  	    			LCD_reg.LCD_RAM_WR = htoa_lo(var);
			}
  			else
  	 		if (*chr_ptr == 'w') {  	  	// display 1 word hex 0000-FFFF
               chr_ptr++;
               var = *var_ptr--;       // back up 1 char				
  	    			var = *var_ptr++;       // get integer
  	    			LCD_reg.LCD_RAM_WR = htoa_hi(var);
               BusyCheck();
  	    			LCD_reg.LCD_RAM_WR = htoa_lo(var);
               BusyCheck();
               var = *var_ptr++;      // get low byte
               LCD_reg.LCD_RAM_WR = htoa_hi(var);
               BusyCheck();
               LCD_reg.LCD_RAM_WR = htoa_lo(var);
  	  		}
			else {
  				LCD_reg.LCD_RAM_WR = *chr_ptr++;	//write character to LCD Display RAM
  	     	}
		}
 		else
		{
  			LCD_reg.LCD_RAM_WR = *chr_ptr++;		//write character to LCD Display RAM
		}
	}
}

/*------------------------------------------------------------------------------
lcd_clear()

This function is used to clear the LCD.
------------------------------------------------------------------------------*/
void lcd_clear(void)  
	{
	BusyCheck();
	LCD_reg.LCD_CMD_WR = 0x01;
	Cursor_LCD = DD_ADDR;
	}

/*------------------------------------------------------------------------------
MoveCursor(m_direction, m_step)

This function is used to move the cursor on the LCD.

m_direction - char
			- the direction to move the cursor from the current location. 
m_step		- unsigned char 
			- the number of character positions to the move the cursor in the
         		direction specified by m_direction.
------------------------------------------------------------------------------*/

void MoveCursor(char m_direction, unsigned char m_step)
{
	unsigned char i;

	BusyCheck();
	LCD_reg.LCD_CMD_WR = 0x0C;				//Close cursor
	BusyCheck();
	LCD_reg.LCD_CMD_WR = 0x02;				//Cursor home
	
	if(m_step>=16)
	{	
		m_step=m_step-16;
		printfLCD("\n");
	}
	for(i=0;i<m_step;i++)
	{
		BusyCheck();
		if(m_direction==1)LCD_reg.LCD_CMD_WR = 0x10;//Left shift
		else LCD_reg.LCD_CMD_WR = 0x14;				//Right shift
	}
	BusyCheck();
	LCD_reg.LCD_CMD_WR = 0x0E;						//Open Cursor
}


	
/* The following conversion functions are used in conjunction with the
 displaying data on the LCD. */

/*------------------------------------------------------------------------------
htoa_lo(byte)

This function is used to convert the low nibble of an unsigned byte (0-F hex)
to ASCII.

byte	- byte 
		- byte to convert to ASCII.

Returns:
ASCII value result of the conversion.
------------------------------------------------------------------------------*/
char htoa_lo(byte)
				
unsigned char byte;
	{
	byte = byte & 0x0F;			// keep lower nibble only   
	if (byte <= 0x09)
		return(byte + 0x30);
	else
		return (byte + 0x37);
	}

/*------------------------------------------------------------------------------
htoa_hi(byte)

This function is used to convert the hi nibble of an unsigned byte (0-F hex)
to ASCII.

byte 	- byte 
		- byte to convert to ASCII.

Returns:
ASCII value result of the conversion.
------------------------------------------------------------------------------*/
char htoa_hi(byte)	 

unsigned char byte;
	{
	byte = byte & 0xF0;			// keep upper nibble only   
	byte = byte >> 4;
	if (byte <= 0x09)
		return(byte + 0x30);
	else
		return (byte + 0x37);
	}