LCD_driver.c

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/* This file has been prepared for Doxygen automatic documentation generation.*/
// Include files.
#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)
__flash unsigned int LCD_character_table[] = // 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)
};


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
}


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];
        }

        // 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 );
}


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 );
}


#pragma vector = LCD_SOF_vect
__interrupt void LCD_SOF_interrupt( void )
{
        unsigned char i;
        unsigned char *src, *dest;

        LCD_timer--;
        if( LCD_timer == 0 )    // if time out
        {
            if( LCD_status.updateRequired == TRUE )
                {
                        LCD_timer = LCD_TIMER_SEED;         // Reload the LCD_timer
                        LCD_status.updateComplete = TRUE;       // Set the LCD_ScrollReady to true.
                        LCD_status.blinkLCD = ~LCD_status.blinkLCD;             // Toggle LCD_Blink variable.

                        // Copy display data buffer to I/O segment registers.
                        i = 20;
                        dest = &pLCDREG;
                        src = LCD_displayData;
                        do
                        {
                                *dest++ = *src++;
                        } while ( --i );
                }
                else
                {
                  LCD_timer = 1;              //If LCD timer allows update of the LCD, but update is blocked
                                              // by LCD_status.updateRequired == FALSE the LCD_timer is preloaded
                                              // with smallest timer seed to ensure fastest LCD update.
          LCD_status.updateComplete = FALSE;  //Block for further access to the LCD_displayData until
                                              // LCD update has been performed.
                }
        }
}

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