text: #ifndef LCD_H
  #define LCD_H
  /*************************************************************************
   Title	:   C include file for the HD44780U LCD library (lcd.c)
   Author:    Peter Fleury <pfleury@gmx.ch>  http://jump.to/fleury
   File:	    $Id: lcd.h,v 1.1 2006-02-05 18:28:00 mah Exp $
   Software:  AVR-GCC 3.3
   Hardware:  any AVR device, memory mapped mode only for AT90S4414/8515/Mega
  ***************************************************************************/
  
  /**
   @defgroup pfleury_lcd LCD library
   @code #include <lcd.h> @endcode
   
   @brief Basic routines for interfacing a HD44780U-based text LCD display
  
   Originally based on Volker Oth's LCD library,
   changed lcd_init(), added additional constants for lcd_command(), 
   added 4-bit I/O mode, improved and optimized code.
         
   Library can be operated in memory mapped mode (LCD_IO_MODE=0) or in 
   4-bit IO port mode (LCD_IO_MODE=1). 8-bit IO port mode not supported.
  
   Memory mapped mode compatible with Kanda STK200, but supports also 
   generation of R/W signal through A8 address line.
         
   @author Peter Fleury pfleury@gmx.ch http://jump.to/fleury
   
   @see The chapter <a href="http://homepage.sunrise.ch/mysunrise/peterfleury/avr-lcd44780.html" target="_blank">Interfacing a HD44780 Based LCD to an AVR</a>
        on my home page.
  
  */
  
  /*@{*/
  
  #if (__GNUC__ * 100 + __GNUC_MINOR__) < 303
  #error "This library requires AVR-GCC 3.3 or later, update to newer AVR-GCC compiler !"
  #endif
  
  #include <inttypes.h>
  #include <avr/pgmspace.h>
  
  /** 
   *  @name  Definitions for MCU Clock Frequency
   *  Adapt the MCU clock frequency in Hz to your target. 
   */
  #define XTAL F_CPU
  
  /** 
   *  @name  Definitions for Display Size 
   *  Change these definitions to adapt setting to your display
   */
  #define LCD_LINES           2     /**< number of visible lines of the display */
  #define LCD_DISP_LENGTH    16     /**< visibles characters per line of the display */
  #define LCD_LINE_LENGTH  0x40     /**< internal line length of the display    */
  #define LCD_START_LINE1  0x00     /**< DDRAM address of first char of line 1 */
  #define LCD_START_LINE2  0x40     /**< DDRAM address of first char of line 2 */
  #define LCD_START_LINE3  0x14     /**< DDRAM address of first char of line 3 */
  #define LCD_START_LINE4  0x54     /**< DDRAM address of first char of line 4 */
  #define LCD_WRAP_LINES      0     /**< 0: no wrap, 1: wrap at end of visibile line */
  
  
  #define LCD_IO_MODE      1         /**< 0: memory mapped mode, 1: IO port mode */
  #if LCD_IO_MODE
  /**
   *  @name Definitions for 4-bit IO mode
   *  Change LCD_PORT if you want to use a different port for the LCD pins.
   *
   *  The four LCD data lines and the three control lines RS, RW, E can be on the 
   *  same port or on different ports. 
   *  Change LCD_RS_PORT, LCD_RW_PORT, LCD_E_PORT if you want the control lines on
   *  different ports. 
   *
   *  Normally the four data lines should be mapped to bit 0..3 on one port, but it
   *  is possible to connect these data lines in different order or even on different
   *  ports by adapting the LCD_DATAx_PORT and LCD_DATAx_PIN definitions.
   *  
   */
  #define LCD_PORT         PORTC        /**< port for the LCD lines   */
  #define LCD_DATA0_PORT   LCD_PORT     /**< port for 4bit data bit 0 */
  #define LCD_DATA1_PORT   LCD_PORT     /**< port for 4bit data bit 1 */
  #define LCD_DATA2_PORT   LCD_PORT     /**< port for 4bit data bit 2 */
  #define LCD_DATA3_PORT   LCD_PORT     /**< port for 4bit data bit 3 */
  #define LCD_DATA0_PIN    4            /**< pin for 4bit data bit 0  */
  #define LCD_DATA1_PIN    5            /**< pin for 4bit data bit 1  */
  #define LCD_DATA2_PIN    6            /**< pin for 4bit data bit 2  */
  #define LCD_DATA3_PIN    7            /**< pin for 4bit data bit 3  */
  #define LCD_RS_PORT      PORTC     /**< port for RS line         */
  #define LCD_RS_PIN       0            /**< pin  for RS line         */
  #define LCD_RW_PORT      PORTC /**< port for RW line         */
  #define LCD_RW_PIN       1            /**< pin  for RW line         */
  #define LCD_E_PORT       PORTC /**< port for Enable line     */
  #define LCD_E_PIN        2            /**< pin  for Enable line     */
  
  #elif defined(__AVR_AT90S4414__) || defined(__AVR_AT90S8515__) || defined(__AVR_ATmega64__) || \
        defined(__AVR_ATmega8515__)|| defined(__AVR_ATmega103__) || defined(__AVR_ATmega128__) || \
        defined(__AVR_ATmega161__) || defined(__AVR_ATmega162__)
  /*
   *  memory mapped mode is only supported when the device has an external data memory interface
   */
  #define LCD_IO_DATA      0xC000    /* A15=E=1, A14=RS=1                 */
  #define LCD_IO_FUNCTION  0x8000    /* A15=E=1, A14=RS=0                 */
  #define LCD_IO_READ      0x0100    /* A8 =R/W=1 (R/W: 1=Read, 0=Write   */
  #else
  #error "external data memory interface not available for this device, use 4-bit IO port mode"
  
  #endif
  
  
  /**
   *  @name Definitions for LCD command instructions
   *  The constants define the various LCD controller instructions which can be passed to the 
   *  function lcd_command(), see HD44780 data sheet for a complete description.
   */
  
  /* instruction register bit positions, see HD44780U data sheet */
  #define LCD_CLR               0      /* DB0: clear display                  */
  #define LCD_HOME              1      /* DB1: return to home position        */
  #define LCD_ENTRY_MODE        2      /* DB2: set entry mode                 */
  #define LCD_ENTRY_INC         1      /*   DB1: 1=increment, 0=decrement     */
  #define LCD_ENTRY_SHIFT       0      /*   DB2: 1=display shift on           */
  #define LCD_ON                3      /* DB3: turn lcd/cursor on             */
  #define LCD_ON_DISPLAY        2      /*   DB2: turn display on              */
  #define LCD_ON_CURSOR         1      /*   DB1: turn cursor on               */
  #define LCD_ON_BLINK          0      /*     DB0: blinking cursor ?          */
  #define LCD_MOVE              4      /* DB4: move cursor/display            */
  #define LCD_MOVE_DISP         3      /*   DB3: move display (0-> cursor) ?  */
  #define LCD_MOVE_RIGHT        2      /*   DB2: move right (0-> left) ?      */
  #define LCD_FUNCTION          5      /* DB5: function set                   */
  #define LCD_FUNCTION_8BIT     4      /*   DB4: set 8BIT mode (0->4BIT mode) */
  #define LCD_FUNCTION_2LINES   3      /*   DB3: two lines (0->one line)      */
  #define LCD_FUNCTION_10DOTS   2      /*   DB2: 5x10 font (0->5x7 font)      */
  #define LCD_CGRAM             6      /* DB6: set CG RAM address             */
  #define LCD_DDRAM             7      /* DB7: set DD RAM address             */
  #define LCD_BUSY              7      /* DB7: LCD is busy                    */
  
  /* set entry mode: display shift on/off, dec/inc cursor move direction */
  #define LCD_ENTRY_DEC            0x04   /* display shift off, dec cursor move dir */
  #define LCD_ENTRY_DEC_SHIFT      0x05   /* display shift on,  dec cursor move dir */
  #define LCD_ENTRY_INC_           0x06   /* display shift off, inc cursor move dir */
  #define LCD_ENTRY_INC_SHIFT      0x07   /* display shift on,  inc cursor move dir */
  
  /* display on/off, cursor on/off, blinking char at cursor position */
  #define LCD_DISP_OFF             0x08   /* display off                            */
  #define LCD_DISP_ON              0x0C   /* display on, cursor off                 */
  #define LCD_DISP_ON_BLINK        0x0D   /* display on, cursor off, blink char     */
  #define LCD_DISP_ON_CURSOR       0x0E   /* display on, cursor on                  */
  #define LCD_DISP_ON_CURSOR_BLINK 0x0F   /* display on, cursor on, blink char      */
  
  /* move cursor/shift display */
  #define LCD_MOVE_CURSOR_LEFT     0x10   /* move cursor left  (decrement)          */
  #define LCD_MOVE_CURSOR_RIGHT    0x14   /* move cursor right (increment)          */
  #define LCD_MOVE_DISP_LEFT       0x18   /* shift display left                     */
  #define LCD_MOVE_DISP_RIGHT      0x1C   /* shift display right                    */
  
  /* function set: set interface data length and number of display lines */
  #define LCD_FUNCTION_4BIT_1LINE  0x20   /* 4-bit interface, single line, 5x7 dots */
  #define LCD_FUNCTION_4BIT_2LINES 0x28   /* 4-bit interface, dual line,   5x7 dots */
  #define LCD_FUNCTION_8BIT_1LINE  0x30   /* 8-bit interface, single line, 5x7 dots */
  #define LCD_FUNCTION_8BIT_2LINES 0x38   /* 8-bit interface, dual line,   5x7 dots */
  
  
  #define LCD_MODE_DEFAULT     ((1<<LCD_ENTRY_MODE) | (1<<LCD_ENTRY_INC) )
  
  
  
  /** 
   *  @name Functions
   */
  
  
  /**
   @brief    Initialize display and select type of cursor
   @param    dispAttr \b LCD_DISP_OFF display off\n
                      \b LCD_DISP_ON display on, cursor off\n
                      \b LCD_DISP_ON_CURSOR display on, cursor on\n
                      \b LCD_DISP_ON_CURSOR_BLINK display on, cursor on flashing             
   @return  none
  */
  extern void lcd_init(uint8_t dispAttr);
  
  
  /**
   @brief    Clear display and set cursor to home position
   @param    void                                        
   @return   none
  */
  extern void lcd_clrscr(void);
  
  
  /**
   @brief    Set cursor to home position
   @param    void                                        
   @return   none
  */
  extern void lcd_home(void);
  
  
  /**
   @brief    Set cursor to specified position
   
   @param    x horizontal position\n (0: left most position)
   @param    y vertical position\n   (0: first line)
   @return   none
  */
  extern void lcd_gotoxy(uint8_t x, uint8_t y);
  
  
  /**
   @brief    Display character at current cursor position
   @param    c character to be displayed                                       
   @return   none
  */
  extern void lcd_putc(char c);
  
  
  /**
   @brief    Display string without auto linefeed
   @param    s string to be displayed                                        
   @return   none
  */
  extern void lcd_puts(const char *s);
  
  
  /**
   @brief    Display string from program memory without auto linefeed
   @param    s string from program memory be be displayed                                        
   @return   none
   @see      lcd_puts_P
  */
  extern void lcd_puts_p(const char *progmem_s);
  
  
  /**
   @brief    Send LCD controller instruction command
   @param    cmd instruction to send to LCD controller, see HD44780 data sheet
   @return   none
  */
  extern void lcd_command(uint8_t cmd);
  
  
  /**
   @brief    Send data byte to LCD controller 
   
   Similar to lcd_putc(), but without interpreting LF
   @param    data byte to send to LCD controller, see HD44780 data sheet
   @return   none
  */
  extern void lcd_data(uint8_t data);
  
  
  /**
   @brief macros for automatically storing string constant in program memory
  */
  #define lcd_puts_P(__s)         lcd_puts_p(PSTR(__s))
  
  /*@}*/
  #endif //LCD_H
  