class to drive the HD44780 LCD with PCF8574 I2C interface More...

#include <HD44780_LCD_RDL.hpp>

Inheritance diagram for HD44780PCF8574LCD:

Public Types
enum	LCDBackLight_e : uint8_t { LCDBackLightOnMask = 0x0F , LCDBackLightOffMask = 0x07 }

enum	LCDEntryMode_e : uint8_t { LCDEntryModeOne = 0x04 , LCDEntryModeTwo = 0x05 , LCDEntryModeThree = 0x06 , LCDEntryModeFour = 0x07 }

enum	LCDCursorType_e : uint8_t { LCDCursorTypeOff = 0x0C , LCDCursorTypeBlink = 0x0D , LCDCursorTypeOn = 0x0E , LCDCursorTypeOnBlink = 0x0F }

enum	LCDDirectionType_e : uint8_t { LCDMoveRight = 1 , LCDMoveLeft = 2 }

enum	LCDLineNumber_e : uint8_t { LCDLineNumberOne = 1 , LCDLineNumberTwo = 2 , LCDLineNumberThree = 3 , LCDLineNumberFour = 4 }

Public Types inherited from Print
enum	BaseNum : uint8_t { RDL_DEC = 10 , RDL_HEX = 16 , RDL_OCT = 8 , RDL_BIN = 2 }

Public Member Functions
	HD44780PCF8574LCD (uint8_t NumRow, uint8_t NumCol, int I2Cdevice, int I2Caddress, int I2Cflags)
	Constructor for class HD44780PCF8574LCD.

void	LCDInit (LCDCursorType_e)
	Initialise LCD.

void	LCDDisplayON (bool)
	Turn Screen on and off.

void	LCDResetScreen (LCDCursorType_e)
	Reset screen.

void	LCDBackLightSet (bool)
	Turn LED backlight on and off.

bool	LCDBackLightGet (void)
	get the backlight flag status

rdlib::Return_Codes_e	LCD_I2C_ON (void)
	Switch on the I2C.

rdlib::Return_Codes_e	LCD_I2C_OFF (void)
	End I2C operations.

int	LCDCheckConnection (void)
	checks if LCD on I2C bus

int	LCDI2CErrorGet (void)
	get I2C error Flag

uint16_t	LCDI2CErrorTimeoutGet (void)
	Gets the I2C timeout, used in the event of an I2C write error.

void	LCDI2CErrorTimeoutSet (uint16_t)
	Sets the I2C timeout, in the event of an I2C write error.

uint8_t	LCDI2CErrorRetryNumGet (void)
	Gets the I2C error retry attempts, used in the event of an I2C write error.

void	LCDI2CErrorRetryNumSet (uint8_t)
	Sets the I2C error retry attempts used in the event of an I2C write error.

rdlib::Return_Codes_e	LCDSendString (char *str)
	Send a string to LCD.

void	LCDSendChar (char data)
	Sends a character to screen , simply wraps SendData command.

virtual size_t	write (uint8_t)
	Called by print class, used to print out numerical data types etc.

rdlib::Return_Codes_e	LCDCreateCustomChar (uint8_t location, uint8_t *charmap)
	Saves a custom character to a location in character generator RAM 64 bytes.

void	LCDPrintCustomChar (uint8_t location)
	Print out a customer character from character generator CGRAM 64 bytes 8 characters.

void	LCDMoveCursor (LCDDirectionType_e, uint8_t moveSize)
	Moves cursor.

void	LCDScroll (LCDDirectionType_e, uint8_t ScrollSize)
	Scrolls screen.

void	LCDGOTO (LCDLineNumber_e lineNo, uint8_t col)
	moves cursor to an x , y position on display.

void	LCDClearLine (LCDLineNumber_e lineNo)
	Clear a line by writing spaces to every position.

rdlib::Return_Codes_e	LCDClearScreen (void)
	Clear screen by writing spaces to every position.

void	LCDClearScreenCmd (void)
	Clear display using software command , set cursor position to zero.

void	LCDHome (void)
	Set cursor position to home position .

void	LCDChangeEntryMode (LCDEntryMode_e mode)
	Change entry mode.

Public Member Functions inherited from Print
int	getWriteError ()
	gets the error flag status, zero no error

void	clearWriteError ()
	clears the error flag by setting it to zero

virtual size_t	write (const uint8_t *buffer, size_t size)
	define in the sub class

size_t	write (const char *str)
	Writes a string to the output.

size_t	write (const char *buffer, size_t size)
	Writes a buffer of a specified size to the output.

virtual int	availableForWrite ()
	define in the sub class

size_t	print (const char[])
	print an array

size_t	print (char)
	print an character

size_t	print (int, int=RDL_DEC)
	print an integer of base number system

size_t	print (unsigned int, int=RDL_DEC)
	print an unsigned integer of base number system

size_t	print (long, int=RDL_DEC)
	print an long integer of base number system

size_t	print (unsigned long, int=RDL_DEC)
	print an unsigned long integer of base number system

size_t	print (double, int=2)
	print an double

size_t	print (const std::string &)
	print an C++ string object

size_t	println (const char[])
	Prints a character array followed by a newline.

size_t	println (char)
	print an character followed by new line

size_t	println (int, int=RDL_DEC)
	print an integer of base number system followed by new line

size_t	println (unsigned int, int=RDL_DEC)
	print an unsigned integer of base number system followed by new line

size_t	println (long, int=RDL_DEC)
	print an long integer of base number system followed by new line

size_t	println (unsigned long, int=RDL_DEC)
	print an unsigned long integer of base number system followed by new line

size_t	println (double, int=2)
	print an double

size_t	println (void)
	Goto to new line.

size_t	println (const std::string &s)
	print an C++ string object followed by new line

template<typename T >
size_t	print (const std::vector< T > &v, int format=defaultFormat< T >())
	Print a vector of any type.

template<typename T >
size_t	println (const std::vector< T > &vec, int format=defaultFormat< T >())
	Print a vector of elements followed by a newline.

template<typename T , size_t N>
size_t	print (const std::array< T, N > &arr, int format=defaultFormat< T >())
	Print a std::array of any type.

template<typename T , size_t N>
size_t	println (const std::array< T, N > &arr, int format=defaultFormat< T >())
	Print a std::array of elements followed by a newline.

Private Types
enum	LCDAddress_e : uint8_t { LCDLineAddressOne = 0x80 , LCDLineAddressTwo = 0xC0 , LCDLineAddress3Col20 = 0x94 , LCDLineAddress4Col20 = 0xD4 , LCDLineAddress3Col16 = 0x90 , LCDLineAddress4Col16 = 0xD0 }

enum	LCDCmdBytesGeneral_e : uint8_t { LCDCmdModeFourBit = 0x28 , LCDCmdHomePosition = 0x02 , LCDCmdDisplayOn = 0x0C , LCDCmdDisplayOff = 0x08 , LCDCmdClearScreen = 0x01 }

Private Member Functions
void	LCDSendCmd (unsigned char cmd)
	Send command byte to lcd.

void	LCDSendData (unsigned char data)
	Send data byte to LCD via I2C.

Private Attributes
enum LCDBackLight_e	_LCDBackLight = LCDBackLightOnMask

int	_LCDI2CAddress = 0x27

int	_LCDI2CDevice = 1

int	_LCDI2CFlags = 0

int	_LCDI2CHandle = 0

uint16_t	_I2C_ErrorDelay = 100

uint8_t	_I2C_ErrorRetryNum = 3

int	_I2C_ErrorFlag = 0

uint8_t	_NumRowsLCD = 2

uint8_t	_NumColsLCD = 16

Additional Inherited Members
Protected Member Functions inherited from Print
void	setWriteError (int err=0)

Detailed Description

class to drive the HD44780 LCD with PCF8574 I2C interface

Member Enumeration Documentation

◆ LCDAddress_e

enum HD44780PCF8574LCD::LCDAddress_e : uint8_t

private

DDRAM address's used to set cursor position Note Private

Enumerator
LCDLineAddressOne	Line 1
LCDLineAddressTwo	Line 2
LCDLineAddress3Col20	Line 3 20x04 line 3
LCDLineAddress4Col20	Line 4 20x04 line 4
LCDLineAddress3Col16	Line 3 16x04 untested, no part
LCDLineAddress4Col16	Line 4 16x04 untested, no part

◆ LCDBackLight_e

enum HD44780PCF8574LCD::LCDBackLight_e : uint8_t

Backlight Control , Command Byte Code

Enumerator
LCDBackLightOnMask	XXXX-1111 , Turn on Back light
LCDBackLightOffMask	XXXX-0111, Turn off Back light

◆ LCDCmdBytesGeneral_e

enum HD44780PCF8574LCD::LCDCmdBytesGeneral_e : uint8_t

private

Command Bytes General Note Private

Enumerator
LCDCmdModeFourBit	Function set (4-bit interface, 2 lines, 5*7 Pixels)
LCDCmdHomePosition	Home (move cursor to top/left character position)
LCDCmdDisplayOn	Restore the display (with cursor hidden)
LCDCmdDisplayOff	Blank the display (without clearing)
LCDCmdClearScreen	clear screen command byte

◆ LCDCursorType_e

enum HD44780PCF8574LCD::LCDCursorType_e : uint8_t

Cursor mode, Command Byte Code

Enumerator
LCDCursorTypeOff	Make cursor invisible
LCDCursorTypeBlink	Turn on blinking-block cursor
LCDCursorTypeOn	Turn on visible underline cursor
LCDCursorTypeOnBlink	Turn on blinking-block cursor + visible underline cursor

◆ LCDDirectionType_e

enum HD44780PCF8574LCD::LCDDirectionType_e : uint8_t

Direction mode for scroll and move

Enumerator
LCDMoveRight	move or scroll right
LCDMoveLeft	move or scroll left

◆ LCDEntryMode_e

enum HD44780PCF8574LCD::LCDEntryMode_e : uint8_t

Entry mode control set command, Command Byte Code

Enumerator
LCDEntryModeOne	Display Shift :OFF Decrement Address Counter
LCDEntryModeTwo	Display Shift :ON Decrement Address Counter
LCDEntryModeThree	Display Shift :OFF Increment Address Counter, default
LCDEntryModeFour	Display Shift :ON Increment Address Counter

◆ LCDLineNumber_e

enum HD44780PCF8574LCD::LCDLineNumber_e : uint8_t

Line Row Number

Enumerator
LCDLineNumberOne	row 1
LCDLineNumberTwo	row 2
LCDLineNumberThree	row 3
LCDLineNumberFour	row 4

Constructor & Destructor Documentation

◆ HD44780PCF8574LCD()

HD44780PCF8574LCD::HD44780PCF8574LCD	(	uint8_t	NumRow,
		uint8_t	NumCol,
		int	I2CDevice,
		int	I2Caddress,
		int	I2CFlags
	)

Constructor for class HD44780PCF8574LCD.

Parameters

NumRow	number of rows in LCD
NumCol	number of columns in LCD
I2CDevice	An I2C device number.
I2Caddress	The address of a device on the I2C bus. PCF8574 default is 0x27.
I2CFlags	Flags which modify an I2C open command. None are currently defined.

Member Function Documentation

◆ LCD_I2C_OFF()

rdlib::Return_Codes_e HD44780PCF8574LCD::LCD_I2C_OFF ( void )

End I2C operations.

Returns

error for failure to close a I2C bus device

◆ LCD_I2C_ON()

rdlib::Return_Codes_e HD44780PCF8574LCD::LCD_I2C_ON ( void )

Switch on the I2C.

Note: Start I2C operations.

Returns

error for failure to init a I2C bus

◆ LCDBackLightGet()

bool HD44780PCF8574LCD::LCDBackLightGet ( void )

get the backlight flag status

Returns: the status of backlight on or off , true or false.

◆ LCDBackLightSet()

void HD44780PCF8574LCD::LCDBackLightSet ( bool OnOff )

Turn LED backlight on and off.

Parameters

OnOff passed bool True = LED on , false = display LED off

Note: another data or command must be issued before it takes effect.

◆ LCDChangeEntryMode()

void HD44780PCF8574LCD::LCDChangeEntryMode ( LCDEntryMode_e newEntryMode )

Change entry mode.

Parameters

newEntryMode 1-4 , 4 choices.

◆ LCDCheckConnection()

int HD44780PCF8574LCD::LCDCheckConnection ( void )

checks if LCD on I2C bus

Returns: lg Error codes, LG_OKAY 0x00 = Success

Note: Error codes are here https://abyz.me.uk/lg/lgpio.html prints error code text to console

◆ LCDClearLine()

void HD44780PCF8574LCD::LCDClearLine ( LCDLineNumber_e lineNo )

Clear a line by writing spaces to every position.

Parameters

lineNo LCDLineNumber_e enum lineNo 1-4

◆ LCDClearScreen()

rdlib::Return_Codes_e HD44780PCF8574LCD::LCDClearScreen ( void )

Clear screen by writing spaces to every position.

Note: : See also LCDClearScreenCmd for software command clear alternative.

Returns

Success
GenericError of number of rows invalid

◆ LCDClearScreenCmd()

void HD44780PCF8574LCD::LCDClearScreenCmd ( void )

Clear display using software command , set cursor position to zero.

Note: See also LCDClearScreen for manual clear

◆ LCDCreateCustomChar()

rdlib::Return_Codes_e HD44780PCF8574LCD::LCDCreateCustomChar	(	uint8_t	location,
		uint8_t *	charmap
	)

Saves a custom character to a location in character generator RAM 64 bytes.

Parameters

location	CG_RAM location 0-7, we only have 8 locations 64 bytes
charmap	An array of 8 bytes representing a custom character data

Returns

codes

Success
CharArrayNullptr
InvalidRAMLocation

◆ LCDDisplayON()

void HD44780PCF8574LCD::LCDDisplayON ( bool OnOff )

Turn Screen on and off.

Parameters

OnOff True = display on , false = display off

◆ LCDGOTO()

void HD44780PCF8574LCD::LCDGOTO	(	LCDLineNumber_e	line,
		uint8_t	col
	)

moves cursor to an x , y position on display.

Parameters

line	x row 1-4
col	y column 0-15 or 0-19

◆ LCDI2CErrorGet()

int HD44780PCF8574LCD::LCDI2CErrorGet ( void )

get I2C error Flag

See Error Codes at bottom of https://abyz.me.uk/lg/lgpio.html

Returns: I2C error flag

◆ LCDI2CErrorRetryNumGet()

uint8_t HD44780PCF8574LCD::LCDI2CErrorRetryNumGet ( void )

Gets the I2C error retry attempts, used in the event of an I2C write error.

Number of times to retry in event of an error

Returns: _I2C_ErrorRetryNum

◆ LCDI2CErrorRetryNumSet()

void HD44780PCF8574LCD::LCDI2CErrorRetryNumSet ( uint8_t AttemptCount )

Sets the I2C error retry attempts used in the event of an I2C write error.

Number of times to retry in event of an error

Parameters

AttemptCount I2C retry attempts

◆ LCDI2CErrorTimeoutGet()

uint16_t HD44780PCF8574LCD::LCDI2CErrorTimeoutGet ( void )

Gets the I2C timeout, used in the event of an I2C write error.

Delay between retry attempts in event of an error , mS

Returns: I2C timeout delay in mS, _I2C_ErrorDelay

◆ LCDI2CErrorTimeoutSet()

void HD44780PCF8574LCD::LCDI2CErrorTimeoutSet ( uint16_t newTimeout )

Sets the I2C timeout, in the event of an I2C write error.

Delay between retry attempts in event of an error , mS

Parameters

newTimeout I2C timeout delay in mS

◆ LCDInit()

void HD44780PCF8574LCD::LCDInit ( LCDCursorType_e CursorType )

Initialise LCD.

Parameters

CursorType The cursor type 4 choices.

◆ LCDMoveCursor()

void HD44780PCF8574LCD::LCDMoveCursor	(	LCDDirectionType_e	direction,
		uint8_t	moveSize
	)

Moves cursor.

Parameters

direction	enum LCDDirectionType_e left or right
moveSize	number of spaces to move

◆ LCDPrintCustomChar()

void HD44780PCF8574LCD::LCDPrintCustomChar ( uint8_t location )

Print out a customer character from character generator CGRAM 64 bytes 8 characters.

Parameters

location CGRAM 0-7

◆ LCDResetScreen()

void HD44780PCF8574LCD::LCDResetScreen ( LCDCursorType_e CursorType )

Reset screen.

Parameters

CursorType LCDCursorType_e enum cursor type, 4 choices

◆ LCDScroll()

void HD44780PCF8574LCD::LCDScroll	(	LCDDirectionType_e	direction,
		uint8_t	ScrollSize
	)

Scrolls screen.

Parameters

direction	left or right
ScrollSize	number of spaces to scroll

◆ LCDSendChar()

void HD44780PCF8574LCD::LCDSendChar ( char data )

Sends a character to screen , simply wraps SendData command.

Parameters

data	Character to display

◆ LCDSendCmd()

void HD44780PCF8574LCD::LCDSendCmd ( unsigned char cmd )

private

Send command byte to lcd.

Parameters

cmd	command byte

Note: if debug flag == true ,will output data on I2C failures.

◆ LCDSendData()

void HD44780PCF8574LCD::LCDSendData ( unsigned char data )

private

Send data byte to LCD via I2C.

Parameters

data	The data byte to send

Note: if debug flag is true, will output data on I2C failures.

◆ LCDSendString()

rdlib::Return_Codes_e HD44780PCF8574LCD::LCDSendString ( char * str )

Send a string to LCD.

Parameters

str	Pointer to the char array

Returns

codes

Success
CharArrayNullptr
CustomCharLen

◆ write()

size_t HD44780PCF8574LCD::write ( uint8_t character )

virtual

Called by print class, used to print out numerical data types etc.

Parameters

character write a character

Note: used internally. Called by the print method using virtual

Returns: returns 1 to the print class

Implements Print.

Member Data Documentation

◆ _I2C_ErrorDelay

uint16_t HD44780PCF8574LCD::_I2C_ErrorDelay = 100

private

I2C delay(in between retry attempts) in event of error in mS

◆ _I2C_ErrorFlag

int HD44780PCF8574LCD::_I2C_ErrorFlag = 0

private

In event of I2C error holds code

◆ _I2C_ErrorRetryNum

uint8_t HD44780PCF8574LCD::_I2C_ErrorRetryNum = 3

private

In event of I2C error number of retry attempts

◆ _LCDBackLight

enum LCDBackLight_e HD44780PCF8574LCD::_LCDBackLight = LCDBackLightOnMask

private

Enum to store backlight status

◆ _LCDI2CAddress

int HD44780PCF8574LCD::_LCDI2CAddress = 0x27

private

I2C address for I2C module PCF8574 backpack on LCD

◆ _LCDI2CDevice

int HD44780PCF8574LCD::_LCDI2CDevice = 1

private

An I2C device number.

◆ _LCDI2CFlags

int HD44780PCF8574LCD::_LCDI2CFlags = 0

private

Flags which modify an I2C open command. None are currently defined.

◆ _LCDI2CHandle

int HD44780PCF8574LCD::_LCDI2CHandle = 0

private

A number referencing an object opened by one of lgI2cOpen

◆ _NumColsLCD

uint8_t HD44780PCF8574LCD::_NumColsLCD = 16

private

number of columns on LCD

◆ _NumRowsLCD

uint8_t HD44780PCF8574LCD::_NumRowsLCD = 2

private

number of rows on LCD

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

Public Types

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ LCDAddress_e

◆ LCDBackLight_e

◆ LCDCmdBytesGeneral_e

◆ LCDCursorType_e

◆ LCDDirectionType_e

◆ LCDEntryMode_e

◆ LCDLineNumber_e

Constructor & Destructor Documentation

◆ HD44780PCF8574LCD()

Member Function Documentation

◆ LCD_I2C_OFF()

◆ LCD_I2C_ON()

◆ LCDBackLightGet()

◆ LCDBackLightSet()

◆ LCDChangeEntryMode()

◆ LCDCheckConnection()

◆ LCDClearLine()

◆ LCDClearScreen()

◆ LCDClearScreenCmd()

◆ LCDCreateCustomChar()

◆ LCDDisplayON()

◆ LCDGOTO()

◆ LCDI2CErrorGet()

◆ LCDI2CErrorRetryNumGet()

◆ LCDI2CErrorRetryNumSet()

◆ LCDI2CErrorTimeoutGet()

◆ LCDI2CErrorTimeoutSet()

◆ LCDInit()

◆ LCDMoveCursor()

◆ LCDPrintCustomChar()

◆ LCDResetScreen()

◆ LCDScroll()

◆ LCDSendChar()

◆ LCDSendCmd()

◆ LCDSendData()

◆ LCDSendString()

◆ write()

Member Data Documentation

◆ _I2C_ErrorDelay

◆ _I2C_ErrorFlag

◆ _I2C_ErrorRetryNum

◆ _LCDBackLight

◆ _LCDI2CAddress

◆ _LCDI2CDevice

◆ _LCDI2CFlags

◆ _LCDI2CHandle

◆ _NumColsLCD

◆ _NumRowsLCD