lcd_driver.c

AVR DRAGON的仿真版配套源程序,包括定时器,LCD驱动,按键处理,AD转换等等.对AVR初学者甚为有用

//*****************************************************************************
//  File........: LCD_driver.c
//  Author(s)...: ATMEL Norway
//  Target(s)...: ATmega169
//  Compiler....: AVR GCC 20060421
//  Description.: Functions used to control the STK502 LCD
//  Revisions...: 1.1
//  YYYYMMDD - VER. - COMMENT                                       - SIGN.
//  20021015 - 1.0  - General modifications and clean up            - JLL
//	20060829 - 1.1  - Ported to AVR GCC                             - TMF, OL
//*****************************************************************************

// Include files.
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include "Main.h"
#include "LCD_driver.h"

union _LCD_status LCD_status = {0x01};    //LCD_status = {0, 0, 0, 0, 0, 0, FALSE, TRUE};
unsigned char LCD_timer = LCD_TIMER_SEED;

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)
unsigned int LCD_character_table[] PROGMEM = // Character definitions table.
{
	0x0A51,		// '*' (?)
	0x2A80,		// '+'
	0x0000,		// ',' (Not defined)
	0x0A00,		// '-'
	0x0A51,		// '.' Used in the Application Note AVR064, to write "degree" in the display
	0x0000,		// '/' (Not defined)
	0x5559,		// '0'
	0x0118,		// '1'
	0x1e11,
	0x1b11,
	0x0b50,
	0x1b41,
	0x1f41,
	0x0111,
	0x1f51,
	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,
	0x0e41,
	0x1d41,
	0x0f50,
	0x2080,
	0x1510,
	0x8648,
	0x1440,
	0x0578,
	0x8570,
	0x1551,
	0x0e51,
	0x9551,
	0x8e51,
	0x9021,
	0x2081,
	0x1550,
	0x4448,
	0xc550,
	0xc028,
	0x2028,		// 'Y' (+ 'y')
	0x5009,		// 'Z' (+ 'z')
	0x0000,		// '[' (Not defined)
	0x0000,		// '\' (Not defined)
	0x0000,		// ']' (Not defined)
	0x0000,		// '^' (Not defined)
	0x0000		// '_' (Not defined)
};


/******************************************************************************************
*
*	Function name : LCD_Init
*
*	Returns :		None
*
*	Parameters :	None
*
*	Purpose :		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
}

/******************************************************************************************
*
*	Function name : LCD_WriteDigit( unsigned char c, unsigned char digit )
*
*	Returns :		None
*
*	Parameters :	Inputs
*                    c - The symbol to be displayed in a LCD digit
*                    digit - The LCD digit that the symbol should be displayed in
*
*	Purpose :		Stores LCD control data in the LCD_displayData buffer.
*                   (The LCD_displayData is latched in the LCD_SOF interrupt).
*
******************************************************************************************/
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 = pgm_read_word( &LCD_character_table[c]);
	}

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

	i = digit-2;
	if ( i >= 6 )
		return;
	i >>= 1;
	ptr = LCD_displayData + i;		// i = {0,0,1,1,2,2}

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


/******************************************************************************************
*
*	Function name : LCD_AllSegments( unsigned char input )
*
*	Returns :		None
*
*	Parameters :	Inputs->
*                     input -  [TRUE;FALSE]=[DISPLAY;HIDE]
*
*	Purpose :		display all or hide all LCD segments on the STK502 LCD
*
******************************************************************************************/
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 Segments
	{
		*ptr++ = input;		// Set/clear the bits in all LCD registers
	} while ( --i );
}


/******************************************************************************
*
*   LCD Interrupt Routine
*
*	Returns :		None
*
*	Parameters :	None
*
*   Purpose: Latch the LCD_displayData and Set LCD_status.updateComplete
*
*******************************************************************************/
ISR(LCD_vect)
{
    unsigned char i;
    unsigned char *src, *dest;

    i = 20;
    dest = &pLCDREG;              // Destination = LCD Data Register start
    src = LCD_displayData;        // source = LCD Display located in SRAM
    do
    {
        *dest++ = *src++;         // Bulk Copy the data into LCD registers
    } while ( --i );

    LCDCRA &= ~(1<<LCDIE);        //Disable LCD_Start_frame interrupt until needed again
}