exploringBB::LCDCharacterDisplay Class Reference

A class that provides an interface to an LCD character module. It provices support for multiple rows and columns and provides methods for formatting and printing text. You should use a 4 wire interface and a 74XX595 to communicate with the display module. More...

#include <LCDCharacterDisplay.h>

Public Member Functions
	LCDCharacterDisplay (SPIDevice *device, int width, int height)
virtual void	write (char c)
virtual void	print (std::string message)
virtual void	clear ()
virtual void	home ()
virtual int	setCursorPosition (int row, int column)
virtual void	setDisplayOff (bool displayOff)
virtual void	setCursorOff (bool cursorOff)
virtual void	setCursorBlink (bool isBlink)
virtual void	setCursorMoveOff (bool cursorMoveOff)
virtual void	setCursorMoveLeft (bool cursorMoveLeft)
virtual void	setAutoscroll (bool isAutoscroll)
virtual void	setScrollDisplayLeft (bool scrollLeft)
virtual	~LCDCharacterDisplay ()

Detailed Description

A class that provides an interface to an LCD character module. It provices support for multiple rows and columns and provides methods for formatting and printing text. You should use a 4 wire interface and a 74XX595 to communicate with the display module.

Constructor & Destructor Documentation

exploringBB::LCDCharacterDisplay::LCDCharacterDisplay	(	SPIDevice *	device,
		int	width,
		int	height
	)

                                                                                 {
        this->device  = device;
        this->width   = width;
        this->height  = height;

        //Default Cursor, Display and Entry states
        this->cursorState  = LCD_CURSOR_DISPLAY;
        this->displayState = LCD_DISPLAY_ON_OFF | DISPLAY_ENTIRE | DISPLAY_CURSOR | DISPLAY_CURSOR_POS;
        this->entryState   = LCD_ENTRY_MODE_SET | ENTRY_MODE_LEFT;

        this->setup4bit();
}

exploringBB::LCDCharacterDisplay::~LCDCharacterDisplay ( )

virtual

                                          {
        this->device->close();
}

Member Function Documentation

void exploringBB::LCDCharacterDisplay::clear ( )

virtual

                               {
        this->command(LCD_CLEAR_DISPLAY);
        usleep(LCD_LONG_DELAY);  //data sheets states that a delay of 1.52ms is required
}

void exploringBB::LCDCharacterDisplay::home ( )

virtual

                              {
        this->command(LCD_RETURN_HOME);
        usleep(LCD_LONG_DELAY);  //data sheets states that a delay of 1.52ms is required
}

void exploringBB::LCDCharacterDisplay::print ( std::string  message )

virtual

                                                {
        for(unsigned int i=0; i<message.length(); i++){
                this->write(message[i]);
        }
}

void exploringBB::LCDCharacterDisplay::setAutoscroll ( bool  isAutoscroll )

virtual

Parameters

setAutoscroll

                                                        {
        if (!isAutoscroll){
                this->entryState = entryState & (~ENTRY_MODE_S);
                this->writeEntryState();
        }
        else{
                this->entryState = entryState | ENTRY_MODE_S;
                this->writeEntryState();
        }
}

void exploringBB::LCDCharacterDisplay::setCursorBlink ( bool  isBlink )

virtual

Turn the blink on or off.

Parameters

isBlink

pass true to turn the blink on, false to turn it off

                                                    {
        if (!isBlink){
                this->displayState = displayState & (~DISPLAY_CURSOR_POS); //bit inversion of DISPLAY_ENTIRE
                this->writeDisplayState();
        }
        else{
                this->displayState = displayState | DISPLAY_CURSOR_POS;
                this->writeDisplayState();
        }
}

void exploringBB::LCDCharacterDisplay::setCursorMoveLeft ( bool  cursorMoveLeft )

virtual

Parameters

cursorMoveLeft

                                                              {
        if (!cursorMoveLeft){
                this->cursorState = cursorState & (~CURSOR_DISPLAY_RL);
                this->writeCursorState();
        }
        else{
                this->cursorState = cursorState | CURSOR_DISPLAY_RL;
                this->writeCursorState();
        }
}

void exploringBB::LCDCharacterDisplay::setCursorMoveOff ( bool  cursorMoveOff )

virtual

Turn the cursor moving On or Off

Parameters

cursorOff

                                                            {
        if (!cursorMoveOff){
                this->cursorState = cursorState & (~CURSOR_DISPLAY_SC);
                this->writeCursorState();
        }
        else{
                this->cursorState = cursorState | CURSOR_DISPLAY_SC;
                this->writeCursorState();
        }
}

void exploringBB::LCDCharacterDisplay::setCursorOff ( bool  cursorOff )

virtual

Turn the cursor on or off.

Parameters

cursorOff

pass true to turn the cursor off, false to turn it back on

                                                    {
        if (cursorOff){
                this->displayState = displayState & (~DISPLAY_CURSOR);
                this->writeDisplayState();
        }
        else{
                this->displayState = displayState | DISPLAY_CURSOR;
                this->writeDisplayState();
        }
}

int exploringBB::LCDCharacterDisplay::setCursorPosition ( int  row, int  column  )

virtual

                                                             {

        if ((column>=this->width)||(row>=this->height)) return -1;
    row = row * LCD_ROW_OFFSET_ADDR;
    int value = (row + column) | LCD_DDRAM_ADDR;
        this->command(value);
        //printf("[%02x]", value);
    return 0;
}

void exploringBB::LCDCharacterDisplay::setDisplayOff ( bool  displayOff )

virtual

Turn the display on or off.

Parameters

displayOff

pass true to turn the display off, false to turn it back on

                                                      {
        if (displayOff){
                this->displayState = displayState & (~DISPLAY_ENTIRE); //bit inversion of DISPLAY_ENTIRE
                this->writeDisplayState();
        }
        else{
                this->displayState = displayState | DISPLAY_ENTIRE;
                this->writeDisplayState();
        }
}

void exploringBB::LCDCharacterDisplay::setScrollDisplayLeft ( bool  scrollLeft )

virtual

Parameters

scrollDisplayLeft

                                                             {
        if (scrollLeft){
                this->entryState = entryState & (~ENTRY_MODE_LEFT);
                this->writeEntryState();
        }
        else{
                this->entryState = entryState | ENTRY_MODE_LEFT;
                this->writeEntryState();
        }
}

void exploringBB::LCDCharacterDisplay::write ( char  c )

virtual

                                     {
        // 4-bit mode. Send lower 4 bits followed by higher 4 bits
        char upper = (c << 4) & 0b11110000;
        char lower = c & 0b11110000;
        // need to write the lower data and toggle the E bit
        this->device->write(lower | 0b00000011);  //lower 4 bits
        usleep(1);                                        //sleep for at least 300ns
        this->device->write(lower | 0b00000001);  //lower 4 bits
        // need to write the upper data and toggle the E bit
        this->device->write(upper | 0b00000011);  //lower 4 bits
        usleep(1);                                        //sleep for at least 300ns
        this->device->write(upper | 0b00000001);  //lower 4 bits
}

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The documentation for this class was generated from the following files:

• /home/molloyd/exploringBB/library/display/LCDCharacterDisplay.h
• /home/molloyd/exploringBB/library/display/LCDCharacterDisplay.cpp