lcd.c

Go to the documentation of this file.

#include <stdint.h>              // typedef uint8_t
#include <string.h>              // memset(), strlen()
#include <stdlib.h>              // utoa()
#include <avr/io.h>              // DDRC, PORTC, DDRD, PORTD
#include <avr/pgmspace.h>        // pgm_read_byte()
#include <compat/deprecated.h>   // cbi(), inp(), outb(), sbi()

#include "sysdef.h" // #define BOARD_LOCO_DEV, BOARD_PROTO_48, BOARD_PROTO_128
#include "lcd.h"

/* [BA040321] added ifdef for different PCB. Value defined in sysdef.h */
#if defined BOARD_LOCO_DEV //EmbeddedLocoNet
#define LCD_DATA_PORT    PORTC     
#define LCD_DATA_DDR     DDRC      
#define LCD_DATA_D4_PIN  1
#define LCD_DATA_D5_PIN  0
#define LCD_DATA_D6_PIN  3
#define LCD_DATA_D7_PIN  2

#define LCD_RS_PORT      PORTD     
#define LCD_RS_DDR       DDRD      
#define LCD_RS_PIN       5

#define LCD_E_PORT       PORTD     
#define LCD_E_DDR        DDRD      
#define LCD_E_PIN        4

#elif defined BOARD_PROTO_128 //ProtoBoardMega128
#define LCD_DATA_PORT    PORTC     
#define LCD_DATA_DDR     DDRC      
#define LCD_DATA_D4_PIN  0
#define LCD_DATA_D5_PIN  1
#define LCD_DATA_D6_PIN  2
#define LCD_DATA_D7_PIN  3

#define LCD_RS_PORT      PORTC     
#define LCD_RS_DDR       DDRC      
#define LCD_RS_PIN       5

#define LCD_E_PORT       PORTC     
#define LCD_E_DDR        DDRC      
#define LCD_E_PIN        4

#elif defined BOARD_PROTO_48 //ProtoBoardMega48
#define LCD_DATA_PORT    PORTD     
#define LCD_DATA_DDR     DDRD      
#define LCD_DATA_D4_PIN  4
#define LCD_DATA_D5_PIN  5
#define LCD_DATA_D6_PIN  6
#define LCD_DATA_D7_PIN  7

#define LCD_RS_PORT      PORTD     
#define LCD_RS_DDR       DDRD      
#define LCD_RS_PIN       2

#define LCD_E_PORT       PORTD     
#define LCD_E_DDR        DDRD      
#define LCD_E_PIN        3


#else //No Board defined (Error)
#    warning "Board not defined"
#endif //Boardtype

/* instruction register bit positions */
#define LCD_CLR             0      
#define LCD_HOME            1      
#define LCD_ENTRY_MODE      2      
#define LCD_ENTRY_INC       1      
#define LCD_ENTRY_SHIFT     2      
#define LCD_ON              3      
#define LCD_ON_DISPLAY      2      
#define LCD_ON_CURSOR       1      
#define LCD_ON_BLINK        0      
#define LCD_MOVE            4      
#define LCD_MOVE_DISP       3      
#define LCD_MOVE_RIGHT      2      
#define LCD_FUNCTION        5      
#define LCD_FUNCTION_8BIT   4      
#define LCD_FUNCTION_2LINES 3      
#define LCD_FUNCTION_10DOTS 2      
#define LCD_CGRAM           6      
#define LCD_DDRAM           7      
#define LCD_BUSY            7      
/* set entry mode: display shift on/off, dec/inc cursor move direction */
#define LCD_ENTRY_DEC            0x04   
#define LCD_ENTRY_DEC_SHIFT      0x05   
#define LCD_ENTRY_INC_           0x06   
#define LCD_ENTRY_INC_SHIFT      0x07   
/* move cursor/shift display */
#define LCD_MOVE_CURSOR_LEFT     0x10   
#define LCD_MOVE_CURSOR_RIGHT    0x14   
#define LCD_MOVE_DISP_LEFT       0x18   
#define LCD_MOVE_DISP_RIGHT      0x1C   
/* function set: set interface data length and number of display lines */
#define LCD_FUNCTION_4BIT_1LINE  0x20   
#define LCD_FUNCTION_4BIT_2LINES 0x28   
#define LCD_FUNCTION_8BIT_1LINE  0x30   
#define LCD_FUNCTION_8BIT_2LINES 0x38   
#define LCD_START_LINE1  0x00     
#define LCD_START_LINE2  0x40     
#define LCD_START_LINE3  0x10     
#define LCD_START_LINE4  0x50     
#define LCD_MODE_DEFAULT     ((1<<LCD_ENTRY_MODE) | (1<<LCD_ENTRY_INC) )

#define LCD_STROBE()  (sbi(LCD_E_PORT, LCD_E_PIN), cbi(LCD_E_PORT, LCD_E_PIN))
#define LCD_DATA_BITS (_BV(LCD_DATA_D7_PIN) | _BV(LCD_DATA_D6_PIN) | _BV(LCD_DATA_D5_PIN) | _BV(LCD_DATA_D4_PIN))

#define TIME_S1_MS    ( 1*(F_CPU/4000) ) 
#define delay_us(us)  delay_short( ((TIME_S1_MS*(us))/1000) )

static void delay_short(uint16_t number_of_loops)
{
    /* 4 cpu cycles per loop + 12 cycles overhead when a constant is passed. */
    __asm__ volatile ( "cp  %A0,__zero_reg__ \n\t"  \
                       "cpc %B0,__zero_reg__ \n\t"  \
                       "breq L_EXIT_%=       \n\t"  \
                       "L_%=:                \n\t"  \
                       "sbiw r24,1           \n\t"  \
                       "brne L_%=            \n\t"  \
                       "L_EXIT_%=:           \n\t"  \
                       : /* NO OUTPUT */            \
                       : "w" (number_of_loops)      \
                     );
}

static void lcd_write(uint8_t c)
{
    uint8_t dataBits;

    dataBits = LCD_DATA_PORT & ~LCD_DATA_BITS;
    if (c & 0x80) dataBits |= _BV(LCD_DATA_D7_PIN);
    if (c & 0x40) dataBits |= _BV(LCD_DATA_D6_PIN);
    if (c & 0x20) dataBits |= _BV(LCD_DATA_D5_PIN);
    if (c & 0x10) dataBits |= _BV(LCD_DATA_D4_PIN);
    LCD_DATA_PORT = dataBits;
    LCD_STROBE();

    dataBits &= ~LCD_DATA_BITS;
    if (c & 0x08) dataBits |= _BV(LCD_DATA_D7_PIN);
    if (c & 0x04) dataBits |= _BV(LCD_DATA_D6_PIN);
    if (c & 0x02) dataBits |= _BV(LCD_DATA_D5_PIN);
    if (c & 0x01) dataBits |= _BV(LCD_DATA_D4_PIN);
    LCD_DATA_PORT = dataBits;
    LCD_STROBE();
    delay_us(160);
}

void lcd_clear(void)
{
    cbi(LCD_RS_PORT, LCD_RS_PIN);
    lcd_write(0x1);
    delay_us(4100);
}

void lcd_puts(const char * s)
{
    sbi(LCD_RS_PORT, LCD_RS_PIN);
    while (*s) lcd_write( (uint8_t)(*s++) );
}

void lcd_puts_P(const char * s)
{
    char c;
    sbi(LCD_RS_PORT, LCD_RS_PIN);

    for (c = pgm_read_byte(s); c; ++s, c = pgm_read_byte(s))
    {
        lcd_write( (uint8_t)c );
    }
    //while(*s) lcd_write(*s++);
}

void lcd_putc(char c)
{
    sbi(LCD_RS_PORT, LCD_RS_PIN);
    lcd_write( (uint8_t)c );
}

void lcd_goto(uint8_t x, uint8_t y)
{
    cbi(LCD_RS_PORT, LCD_RS_PIN);

    if (y == 0) { x += LCD_START_LINE1; }
    else if (y == 1) { x += LCD_START_LINE2; }
    else if (y == 2) { x += LCD_START_LINE3; }
    else { x += LCD_START_LINE4; }

    lcd_write(_BV(LCD_DDRAM) | x);
}

void lcd_clrxy(uint8_t x, uint8_t y, uint8_t count)
{
    lcd_goto(x, y);

    while (count--)
        lcd_putc(' ');

    lcd_goto(x, y);
}

void lcd_word(uint16_t value, uint8_t width)
{
    /*unsigned */char outstr[11];
    uint8_t len;

    memset(outstr, ' ', 11);

    len = strlen(utoa(value, outstr + 5, 10));

    lcd_puts(outstr + len + 5 - width);
}

void lcd_init(lcdDisplayMode_t dispAttr)
{
    sbi(LCD_RS_DDR, LCD_RS_PIN);
    sbi(LCD_E_DDR, LCD_E_PIN);
    LCD_DATA_DDR |= LCD_DATA_BITS ;
    cbi(LCD_RS_PORT, LCD_RS_PIN);
    cbi(LCD_E_PORT, LCD_E_PIN);

    // power on delay
    delay_us(16000);

    // Initially configure for 8 bit mode
    sbi(LCD_DATA_PORT, LCD_DATA_D4_PIN);
    sbi(LCD_DATA_PORT, LCD_DATA_D5_PIN);
    LCD_STROBE();
    delay_us(5000);

    // Repeat last command
    LCD_STROBE();
    delay_us(160);

    // Repeat last command a third time
    LCD_STROBE();
    delay_us(160);

    // Now configure for 4 bit mode
    cbi(LCD_DATA_PORT, LCD_DATA_D4_PIN);
    LCD_STROBE();
    delay_us(160);

    lcd_write(LCD_FUNCTION_4BIT_2LINES);
    lcd_write(LCD_DISP_OFF);
    lcd_clear();
    lcd_write(LCD_MODE_DEFAULT);

    // entry mode advance cursor
    lcd_write(LCD_ENTRY_INC_);

    // set passed display attributes
    lcd_write(dispAttr);
}