lcd_driver.c

avr Rtos 255 Task avr Rtos 255 Task

/* This file has been prepared for Doxygen automatic documentation generation.*/
/*! \file *********************************************************************
 *
 * \brief
 *      Functions used to control the STK502 LCD
 *
 * \par Application note:
 *      AVR065: LCD Driver for the STK502
 *
 * \par Documentation:
 *      For comprehensive code documentation, supported compilers, compiler
 *      settings and supported devices see readme.html
 *
 * \author
 *      Atmel Corporation: http://www.atmel.com \n
 *      Support email: [e-mail]
 *
 * $Name: RELEASE_1_1 $
 * $Revision: 1.3 $
 * $RCSfile: LCD_driver.c,v $
 * $Date: 2006/02/16 18:14:01 $  \n
 ******************************************************************************/




// Include files.
#include "defines.h"
#include "LCD_driver.h"  
#include<mega169.h>  
#include "deinclus.h"

union _LCD_status LCD_status = {0x01};    //!< LCD_status = {0, 0, 0, 0, 0, 0, FALSE, TRUE};
unsigned char LCD_timer = LCD_TIMER_SEED;
										// colons.
unsigned char LCD_displayData[LCD_REGISTER_COUNT];		//!< LCD display buffer (for double buffering).

//! Look-up table used when converting ASCII to LCD display data	(segment control)
__flash unsigned int LCD_character_table[] = // Character definitions table.
{
	0x0A51,		// '*' (?)
	0x2A80,		// '+'
	0x0000,		// ',' (Not defined)
	0x0A00,		// '-'
	0x0000,		// '.' (Not defined)
	0x0000,		// '/' (Not defined)
	0x5559,		// '0'
	0x0118,		// '1'
	0x1e11,		// '2'
	0x1b11,		// '3'
	0x0b50,		// '4'
	0x1b41,		// '5'
	0x1f41,		// '6'
	0x0111,		// '7'
	0x1f51,		// '8'
	0x1b51,		// '9'
	0x0000,		// ':' (Not defined)
	0x0000,		// ';' (Not defined)
	0x0000,		// '<' (Not defined)
	0x0000,		// '=' (Not defined)
	0x0000,		// '>' (Not defined)
	0x0000,		// '?' (Not defined)
	0x0000,		// '@' (Not defined)
	0x0f51,		// 'A' (+ 'a')
	0x3991,		// 'B' (+ 'b')
	0x1441,		// 'C' (+ 'c')
	0x3191,		// 'D' (+ 'd')
	0x1e41,		// 'E' (+ 'e')
	0x0e41,		// 'F' (+ 'f')
	0x1d41,		// 'G' (+ 'g')
	0x0f50,		// 'H' (+ 'h')
	0x2080,		// 'I' (+ 'i')
	0x1510,		// 'J' (+ 'j')
	0x8648,		// 'K' (+ 'k')
	0x1440,		// 'L' (+ 'l')
	0x0578,		// 'M' (+ 'm')
	0x8570,		// 'N' (+ 'n')
	0x1551,		// 'O' (+ 'o')
	0x0e51,		// 'P' (+ 'p')
	0x9551,		// 'Q' (+ 'q')
	0x8e51,		// 'R' (+ 'r')
	0x9021,		// 'S' (+ 's')
	0x2081,		// 'T' (+ 't')
	0x1550,		// 'U' (+ 'u')
	0x4448,		// 'V' (+ 'v')
	0xc550,		// 'W' (+ 'w')
	0xc028,		// 'X' (+ 'x')
	0x2028,		// 'Y' (+ 'y')
	0x5009,		// 'Z' (+ 'z')
	0x0000,		// '[' (Not defined)
	0x0000,		// '\' (Not defined)
	0x0000,		// ']' (Not defined)
	0x0000,		// '^' (Not defined)
	0x0000		// '_' (Not defined)
};


/*! \brief  Initialize LCD_displayData buffer. Set up the LCD (timing, contrast, etc.)
 */
void LCD_Init (void)
{
	LCD_AllSegments( FALSE );	// Clear segment buffer.
	LCDCRA = (1<<LCDEN);		// Enable LCD.

    LCD_CONTRAST_LEVEL(LCD_INITIAL_CONTRAST);    //Set the LCD contrast level

	// Select asynchronous clock source, enable all COM pins and enable all segment pins.
	LCDCRB = (1<<LCDCS) | (1<<LCDMUX1) | (1<<LCDMUX0) | (1<<LCDPM2) | (1<<LCDPM1)| (1<<LCDPM0);
	LCDFRR = (1<<LCDPS0);                       // Set LCD prescaler to CLK(lcd)/64 = 64Hz.

	LCDCRA |= (1<<LCDIE);	                    //Enable LCD_Start_frame interrupt
}


/*! \brief  Stores LCD control data in the LCD_displayData buffer.
 *           (The LCD_displayData is latched in the LCD_SOF interrupt).
 *
 *  \param  c - The symbol to be displayed in a LCD digit.
 *  \param  digit - The LCD digit that the symbol should be displayed in.
 */
void LCD_WriteDigit( unsigned char c, unsigned char digit )
{

	unsigned int seg;
	unsigned char i;
	unsigned char mask, nibble;
	unsigned char *ptr;

	//Lookup character table for segmet data
	seg = 0x0000;
	if ( (c >= '*') && (c <= 'z') )
	{
		// c is in character_table.
		// Convert to upper if necessarry.
		if ( c >= 'a' ) c &= ~0x20;
		c -= '*';
		seg = LCD_character_table[c];
	}
	else
	{
		return;		//ASCII code out of range
	}

	// Adjust mask according to digit
	mask = 0x0F;		// (1), 3, 5, 7
	if ( digit & 0x01 )
	{
		//left empty to optimize code size
	}
	else
	{
		mask = 0xF0;		// (0), 2, 4, 6
	}

	i = digit-2;		//i used as pointer offset
	if ( i >= 6 )		//Test if LCD digit is out of range
		return;
	i >>= 1;
	ptr = LCD_displayData + i;	// Point to the first relevant LCDDR; i = {0,0,1,1,2,2}

	i = 4;			//i used as loop counter
	do
	{
		nibble = seg & 0x000F;
		seg >>= 4;
		if ( digit & 0x01 )
			nibble <<= 4;
		*ptr = (*ptr & mask) | nibble;
		ptr += 5;
	} while ( --i );
}


/*! \brief  display all or hide all LCD segments on the STK502 LCD.
 *
 *  \param  input -  [TRUE;FALSE]=[DISPLAY;HIDE].
 */
void LCD_AllSegments( unsigned char input )
{
	unsigned char i;
	unsigned char *ptr;

	if( input )				    // if input == TRUE
		input = 0xFF;			// set setgemts to 0xFF
								// (else set segments to 0x00)
	
	ptr = LCD_displayData;
	i = 20;
	do							// Set all LCD segment register to the variable ucSegments
	{
		*ptr++ = input;		// Set/clear the bits in all LCD registers
	} while ( --i );
}