This class provides a high-level interface via I2C to an LCD such as those offered by AdaFruit and SparkFun. Specifically, it communicates via I2C with an MCP23017 that drives an HD44780U controlling an LCD. It also lets you detect button presses on the 5-button keypad generally assocaited with such devices. More...

#include <I2cLcd.h>

Inheritance diagram for I2cLcd:

[legend]

Collaboration diagram for I2cLcd:

[legend]

Public Types
enum	{ kButton_Select, kButton_Right, kButton_Down, kButton_Up, kButton_Left }

enum	{ kBacklight_Red, kBacklight_Yellow, kBacklight_Green, kBacklight_Teal, kBacklight_Blue, kBacklight_Violet, kBacklight_White }

enum	IntegerOutputBase { kBin = 2, kOct = 8, kDec = 10, kHex = 16 }
	An enumeration that defines the number that will be used as the base for representing integer quantities as a string of characters. More...

Public Member Functions
	I2cLcd ()
	Constructor simply initializes some internal bookkeeping.

int	init ()
	Initialize the I2cLcd object. This must be called before using the I2cLcd, or calling any of the other member functions. The I2C system must be initialized before calling this function (by calling I2cMaster::start() from I2cMaster.h). More...

void	clear ()
	Clear the display (all rows, all columns).

void	home ()
	Move the cursor home (the top row, left column).

void	displayTopRow (const char *str)
	Display a C-string on the top row. More...

void	displayBottomRow (const char *str)
	Display a C-string on the bottom row. More...

void	clearTopRow ()
	Clear the top row.

void	clearBottomRow ()
	Clear the bottom row.

void	displayOff ()
	Turn the display off.

void	displayOn ()
	Turn the display on.

void	blinkOff ()
	Do not blink the cursor.

void	blinkOn ()
	Blink the cursor.

void	cursorOff ()
	Hide the cursor.

void	cursorOn ()
	Display the cursor.

void	scrollDisplayLeft ()
	Scroll the display to the left.

void	scrollDisplayRight ()
	Scroll the display to the right.

void	autoscrollOn ()
	Turn on automatic scrolling of the display.

void	autoscrollOff ()
	Turn off automatic scrolling of the display.

void	setCursor (uint8_t row, uint8_t col)
	Move the cursor the a particular row and column. More...

int	setBacklight (uint8_t color)
	Set the backlight to a given color. Set a black-and-white LCD display to White if you want to have a backlight. More...

void	command (uint8_t cmd)
	Pass a command to the LCD. More...

uint8_t	readButtons ()
	Read the state of the buttons associated with the LCD display. More...

virtual size_t	write (char c)
	Write a single character to the LCD at the current cursor location. This implements the pure virtual function Writer::write( char c ). More...

virtual size_t	write (const char *str)
	Write a C-string to the LCD at the current cursor location. This implements the pure virtual function Writer::write( const char* str ). More...

virtual size_t	write (const char *buffer, size_t size)
	Write a given number of characters from a buffer to the LCD at the current cursor location. This implements the pure virtual function Writer::write( const char* buffer, size_t size ). More...

virtual size_t	write (const uint8_t *buffer, size_t size)
	Write a given number of bytes from a buffer to the LCD at the current cursor location. This implements the pure virtual function Writer::write( const uint8_t* buffer, size_t size ). More...

virtual void	flush ()
	This function does nothing. It simply implements the pure virtual function Writer::flush().

size_t	print (const char *str, bool addLn=false)
	Print a null-terminated string to the output stream, with or without adding a new line character at the end. More...

size_t	print (const uint8_t *buf, size_t size, bool addLn=false)
	Print a number of bytes to the output stream, with or without adding a new line character at the end. More...

size_t	print (char c, bool addLn=false)
	Print a single character to the output stream, with or without adding a new line character at the end. More...

size_t	print (int8_t n, int base=kDec, bool addLn=false)
	Print an 8-bit integer to the output stream, with or without adding a new line character at the end. More...

size_t	print (uint8_t n, int base=kDec, bool addLn=false)
	Print an 8-bit unsigned integer to the output stream, with or without adding a new line character at the end. More...

size_t	print (int n, int base=kDec, bool addLn=false)
	Print an integer to the output stream, with or without adding a new line character at the end. More...

size_t	print (unsigned int n, int base=kDec, bool addLn=false)
	Print an unsigned integer to the output stream, with or without adding a new line character at the end. More...

size_t	print (long n, int base=kDec, bool addLn=false)
	Print a long integer to the output stream, with or without adding a new line character at the end. More...

size_t	print (unsigned long n, int base=kDec, bool addLn=false)
	Print an unsigned long integer to the output stream, with or without adding a new line character at the end. More...

size_t	print (double d, int digits=2, bool addLn=false)
	Print a floating point number to the output stream, with or without adding a new line character at the end. More...

size_t	println (const char *str)
	Print a null-terminated string to the output stream, adding a new line character at the end. More...

size_t	println (const uint8_t *buf, size_t size)
	Print a number of bytes to the output stream, adding a new line character at the end. More...

size_t	println (char c)
	Print a single character to the output stream, adding a new line character at the end. More...

size_t	println (int8_t n, int base=kDec)
	Print an 8-bit integer to the output stream, adding a new line character at the end. More...

size_t	println (uint8_t n, int base=kDec)
	Print an 8-bit unsigned integer to the output stream, adding a new line character at the end. More...

size_t	println (int n, int base=kDec)
	Print an integer to the output stream, adding a new line character at the end. More...

size_t	println (unsigned int n, int base=kDec)
	Print an unsigned integer to the output stream, adding a new line character at the end. More...

size_t	println (long n, int base=kDec)
	Print a long integer to the output stream, adding a new line character at the end. More...

size_t	println (unsigned long n, int base=kDec)
	Print an unsigned long integer to the output stream, adding a new line character at the end. More...

size_t	println (double d, int digits=2)
	Print a floating point number to the output stream, adding a new line character at the end. More...

size_t	println ()
	Print a new line to the output stream.

Detailed Description

This class provides a high-level interface via I2C to an LCD such as those offered by AdaFruit and SparkFun. Specifically, it communicates via I2C with an MCP23017 that drives an HD44780U controlling an LCD. It also lets you detect button presses on the 5-button keypad generally assocaited with such devices.

This class derives from Writer, allowing you to write to the LCD much as it if were a serial device.

To use these features, include I2cLcd.h in your source code and link against I2cLcd.cpp and I2cMaster.cpp, and initialize the I2C hardware by calling I2cMaster::start().

Member Enumeration Documentation

§ anonymous enum

anonymous enum

These constants are used to identify the five buttons.

Enumerator
kButton_Select	the Select button
kButton_Right	the Right button
kButton_Down	the Down button
kButton_Up	the Up button
kButton_Left	the Left button

§ anonymous enum

anonymous enum

These constants are used to set the backlight color on the LCD.

Enumerator
kBacklight_Red	Backlight red.
kBacklight_Yellow	Backlight yellow.
kBacklight_Green	Backlight green.
kBacklight_Teal	Backlight teal.
kBacklight_Blue	Backlight blue.
kBacklight_Violet	Backlight violet.
kBacklight_White	Backlight white.

§ IntegerOutputBase

enum Writer::IntegerOutputBase

inherited

An enumeration that defines the number that will be used as the base for representing integer quantities as a string of characters.

Enumerator
kBin	Produce a binary representation of integers (e.g., 11 is output as 0b1011)
kOct	Produce an octal representation of integers (e.g, 11 is output as 013)
kDec	Produce a decimal representation of integers (e.g., 11 is output as 11.
kHex	Produce a hexadecimal representation of integers (e.g., 11 is output as 0x0b)

Member Function Documentation

§ command()

void I2cLcd::command ( uint8_t cmd )

Pass a command to the LCD.

cmd a valid command to send to the HD44780U.

§ displayBottomRow()

void I2cLcd::displayBottomRow ( const char * str )

Display a C-string on the bottom row.

str the C-string to display.

§ displayTopRow()

void I2cLcd::displayTopRow ( const char * str )

Display a C-string on the top row.

str the C-string to display.

§ init()

int I2cLcd::init ( )

Initialize the I2cLcd object. This must be called before using the I2cLcd, or calling any of the other member functions. The I2C system must be initialized before calling this function (by calling I2cMaster::start() from I2cMaster.h).

The LCD display is initialized in 16-column, 2-row mode.

§ print() [1/10]

size_t Writer::print	(	const char *	str,
		bool	addLn = `false`
	)

inherited

Print a null-terminated string to the output stream, with or without adding a new line character at the end.

str is the null-terminated string to output.
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [2/10]

size_t Writer::print	(	const uint8_t *	buf,
		size_t	size,
		bool	addLn = `false`
	)

inherited

Print a number of bytes to the output stream, with or without adding a new line character at the end.

buf is the buffer containing bytes to output.
size is the number of bytes from the buffer to output.
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [3/10]

size_t Writer::print	(	char	c,
		bool	addLn = `false`
	)

inherited

Print a single character to the output stream, with or without adding a new line character at the end.

c is the character to output.
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [4/10]

size_t Writer::print	(	int8_t	n,
		int	base = `kDec`,
		bool	addLn = `false`
	)

inherited

Print an 8-bit integer to the output stream, with or without adding a new line character at the end.

n is the integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [5/10]

size_t Writer::print	(	uint8_t	n,
		int	base = `kDec`,
		bool	addLn = `false`
	)

inlineinherited

Print an 8-bit unsigned integer to the output stream, with or without adding a new line character at the end.

n is the integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [6/10]

size_t Writer::print	(	int	n,
		int	base = `kDec`,
		bool	addLn = `false`
	)

inherited

Print an integer to the output stream, with or without adding a new line character at the end.

n is the integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [7/10]

size_t Writer::print	(	unsigned int	n,
		int	base = `kDec`,
		bool	addLn = `false`
	)

inlineinherited

Print an unsigned integer to the output stream, with or without adding a new line character at the end.

n is the unsigned integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [8/10]

size_t Writer::print	(	long	n,
		int	base = `kDec`,
		bool	addLn = `false`
	)

inherited

Print a long integer to the output stream, with or without adding a new line character at the end.

n is the long integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [9/10]

size_t Writer::print	(	unsigned long	n,
		int	base = `kDec`,
		bool	addLn = `false`
	)

inherited

Print an unsigned long integer to the output stream, with or without adding a new line character at the end.

n is the unsigned long integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ print() [10/10]

size_t Writer::print	(	double	d,
		int	digits = `2`,
		bool	addLn = `false`
	)

inherited

Print a floating point number to the output stream, with or without adding a new line character at the end.

d is the floating point number to output.
digits is the number of decimal digits to output; the default is 2.
addLn if true, a new line character is added at the end of the output; the default is false.

Returns: the number of bytes sent to the output stream.

§ println() [1/10]

size_t Writer::println ( const char * str )

inlineinherited

Print a null-terminated string to the output stream, adding a new line character at the end.

str is the null-terminated string to output.

Returns: the number of bytes sent to the output stream.

§ println() [2/10]

size_t Writer::println	(	const uint8_t *	buf,
		size_t	size
	)

inlineinherited

Print a number of bytes to the output stream, adding a new line character at the end.

buf is the buffer containing bytes to output.
size is the number of bytes from the buffer to output.

Returns: the number of bytes sent to the output stream.

§ println() [3/10]

size_t Writer::println ( char c )

inlineinherited

Print a single character to the output stream, adding a new line character at the end.

c is the character to output.

Returns: the number of bytes sent to the output stream.

§ println() [4/10]

size_t Writer::println	(	int8_t	n,
		int	base = `kDec`
	)

inlineinherited

Print an 8-bit integer to the output stream, adding a new line character at the end.

n is the integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).

Returns: the number of bytes sent to the output stream.

§ println() [5/10]

size_t Writer::println	(	uint8_t	n,
		int	base = `kDec`
	)

inlineinherited

Print an 8-bit unsigned integer to the output stream, adding a new line character at the end.

n is the unsigned integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).

Returns: the number of bytes sent to the output stream.

§ println() [6/10]

size_t Writer::println	(	int	n,
		int	base = `kDec`
	)

inlineinherited

Print an integer to the output stream, adding a new line character at the end.

n is the integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).

Returns: the number of bytes sent to the output stream.

§ println() [7/10]

size_t Writer::println	(	unsigned int	n,
		int	base = `kDec`
	)

inlineinherited

Print an unsigned integer to the output stream, adding a new line character at the end.

n is the unsigned integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).

Returns: the number of bytes sent to the output stream.

§ println() [8/10]

size_t Writer::println	(	long	n,
		int	base = `kDec`
	)

inlineinherited

Print a long integer to the output stream, adding a new line character at the end.

n is the long integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).

Returns: the number of bytes sent to the output stream.

§ println() [9/10]

size_t Writer::println	(	unsigned long	n,
		int	base = `kDec`
	)

inlineinherited

Print an unsigned long integer to the output stream, adding a new line character at the end.

n is the unsigned long integer to output.
base is the base used to represent the number; should be one of IntegerOutputBase; defaults to decimal representation (kDec).

Returns: the number of bytes sent to the output stream.

§ println() [10/10]

size_t Writer::println	(	double	d,
		int	digits = `2`
	)

inlineinherited

Print a floating point number to the output stream, adding a new line character at the end.

d is the flaoting point number to output.
digits is the number of decimal digits to output; the default is 2.

Returns: the number of bytes sent to the output stream.

§ readButtons()

uint8_t I2cLcd::readButtons ( )

Read the state of the buttons associated with the LCD display.

Returns: a byte with flags set corresponding to the buttons that are depressed. You must "and" the return value with kButton_Right, kButton_Left, kButton_Down, kButton_Up, or kButton_Select to determine which buttons have been pressed.

§ setBacklight()

int I2cLcd::setBacklight ( uint8_t color )

Set the backlight to a given color. Set a black-and-white LCD display to White if you want to have a backlight.

color the color to set the backlight. Pass one of kBacklight_Red, kBacklight_Yellow, kBacklight_Green, kBacklight_Teal, kBacklight_Blue, kBacklight_Violet, or kBacklight_White.

§ setCursor()

void I2cLcd::setCursor	(	uint8_t	row,
		uint8_t	col
	)

Move the cursor the a particular row and column.

row the row to move the cursor to (numbering starts at 0).
col the column to move the cursor to (numbering starts at 0).

§ write() [1/4]

size_t I2cLcd::write ( char c )

virtual

Write a single character to the LCD at the current cursor location. This implements the pure virtual function Writer::write( char c ).

the character to be written.

Returns: the number of bytes written.

Implements Writer.

§ write() [2/4]

size_t I2cLcd::write ( const char * str )

virtual

Write a C-string to the LCD at the current cursor location. This implements the pure virtual function Writer::write( const char* str ).

the C-string to be written.

Returns: the number of bytes written.

Implements Writer.

§ write() [3/4]

size_t I2cLcd::write	(	const char *	buffer,
		size_t	size
	)

virtual

Write a given number of characters from a buffer to the LCD at the current cursor location. This implements the pure virtual function Writer::write( const char* buffer, size_t size ).

buffer the buffer of characters to write.
size the number of characters to write

Returns: the number of bytes written.

Implements Writer.

§ write() [4/4]

size_t I2cLcd::write	(	const uint8_t *	buffer,
		size_t	size
	)

virtual

Write a given number of bytes from a buffer to the LCD at the current cursor location. This implements the pure virtual function Writer::write( const uint8_t* buffer, size_t size ).

buffer the buffer of bytes to write.
size the number of bytes to write

Returns: the number of bytes written.

Implements Writer.

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

I2cLcd.h
I2cLcd.cpp

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

§ anonymous enum

§ anonymous enum

§ IntegerOutputBase

Member Function Documentation

§ command()

§ displayBottomRow()

§ displayTopRow()

§ init()

§ print() [1/10]

§ print() [2/10]

§ print() [3/10]

§ print() [4/10]

§ print() [5/10]

§ print() [6/10]

§ print() [7/10]

§ print() [8/10]

§ print() [9/10]

§ print() [10/10]

§ println() [1/10]

§ println() [2/10]

§ println() [3/10]

§ println() [4/10]

§ println() [5/10]

§ println() [6/10]

§ println() [7/10]

§ println() [8/10]

§ println() [9/10]

§ println() [10/10]

§ readButtons()

§ setBacklight()

§ setCursor()

§ write() [1/4]

§ write() [2/4]

§ write() [3/4]

§ write() [4/4]