LiquidCrystal Class Reference

Inheritance diagram for LiquidCrystal:

Public Member Functions
	LiquidCrystal (uint8_t rs, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
	LiquidCrystal (uint8_t rs, uint8_t rw, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
	LiquidCrystal (uint8_t rs, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7, uint8_t backlightPin, t_backlighPol pol)
	LiquidCrystal (uint8_t rs, uint8_t rw, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7, uint8_t backlightPin, t_backlighPol pol)
	LiquidCrystal (uint8_t rs, uint8_t rw, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
	LiquidCrystal (uint8_t rs, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
	LiquidCrystal (uint8_t rs, uint8_t rw, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t backlightPin, t_backlighPol pol)
	LiquidCrystal (uint8_t rs, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t backlightPin, t_backlighPol pol)
virtual void	send (uint8_t value, uint8_t mode)
void	setBacklightPin (uint8_t pin, t_backlighPol pol)
void	setBacklight (uint8_t value)
virtual void	begin (uint8_t cols, uint8_t rows, uint8_t charsize=LCD_5x8DOTS)
void	clear ()
void	home ()
void	noDisplay ()
void	display ()
void	noBlink ()
void	blink ()
void	noCursor ()
void	cursor ()
void	scrollDisplayLeft ()
void	scrollDisplayRight ()
void	leftToRight ()
void	rightToLeft ()
void	moveCursorLeft ()
void	moveCursorRight ()
void	autoscroll ()
void	noAutoscroll ()
void	createChar (uint8_t location, uint8_t charmap[])
void	setCursor (uint8_t col, uint8_t row)
void	backlight (void)
void	noBacklight (void)
void	on (void)
void	off (void)
virtual void	write (uint8_t value)
size_t	write (const char *str)
	Writes a c-string to output stream. More...
virtual size_t	write (const uint8_t *buffer, size_t size)
	Writes characters from a buffer to output stream. More...
size_t	write (const char *buffer, size_t size)
	Writes characters from a buffer to output stream. More...
int	getWriteError ()
	Gets last error. More...
void	clearWriteError ()
	Clears the last write error. More...
size_t	print (char)
	Prints a single character to output stream. More...
size_t	print (const char[])
	Prints a c-string to output stream. More...
size_t	print (unsigned long, int base=DEC)
	Prints a number to output stream. More...
size_t	print (long, int base=DEC)
	Prints a number to output stream. More...
size_t	print (unsigned int, int base=DEC)
size_t	print (unsigned char, int base=DEC)
size_t	print (int, int base=DEC)
	Prints a number to output stream. More...
size_t	print (double, int digits=2)
	Prints number to output stream. More...
size_t	print (const Printable &p)
	Prints a Printable object to output stream. More...
size_t	print (const String &s)
	Prints a String to output stream. More...
size_t	println (void)
	Prints a newline to output stream. More...
size_t	println (const char[])
	Prints a c-string to output stream, appending newline. More...
size_t	println (char)
	Prints a single character to output stream, appending newline. More...
size_t	println (unsigned char, int base=DEC)
	Prints a number to output stream, appending newline. More...
size_t	println (unsigned int, int base=DEC)
size_t	println (unsigned long, int base=DEC)
size_t	println (int, int base=DEC)
	Prints a number to output stream, appending newline. More...
size_t	println (long, int base=DEC)
	Prints a number to output stream, appending newline. More...
size_t	println (double, int digits=2)
	Prints a number to output stream, appending newline. More...
size_t	println (const Printable &p)
	Prints a Printable object to output stream, appending newline. More...
size_t	println (const String &s)
	Prints a String to output stream, appending newline. More...
size_t	printf (const char *fmt,...)
	Prints a formatted c-string to output stream. More...

Protected Member Functions
void	setWriteError (int err=1)

Protected Attributes
uint8_t	_displayfunction
uint8_t	_displaycontrol
uint8_t	_displaymode
uint8_t	_numlines
uint8_t	_cols
t_backlighPol	_polarity

Constructor & Destructor Documentation

LiquidCrystal::LiquidCrystal	(	uint8_t	rs,
		uint8_t	enable,
		uint8_t	d0,
		uint8_t	d1,
		uint8_t	d2,
		uint8_t	d3,
		uint8_t	d4,
		uint8_t	d5,
		uint8_t	d6,
		uint8_t	d7
	)

8 bit LCD constructors. Defines the pin assignment that the LCD will have. The constructor does not initialize the LCD.

LiquidCrystal::LiquidCrystal	(	uint8_t	rs,
		uint8_t	rw,
		uint8_t	enable,
		uint8_t	d0,
		uint8_t	d1,
		uint8_t	d2,
		uint8_t	d3
	)

4 bit LCD constructors. Defines the pin assignment that the LCD will have. The constructor does not initialize the LCD.

Member Function Documentation

void LCD::autoscroll ( )

inherited

Turns on automatic scrolling of the LCD. Turns on automatic scrolling of the LCD. This causes each character output to the display to push previous characters over by one space. If the current text direction is left-to-right (the default), the display scrolls to the left; if the current direction is right-to-left, the display scrolls to the right. This has the effect of outputting each new character to the same location on the LCD.

Parameters

none

void LCD::backlight ( void  )

inherited

Switch-on the LCD backlight. Switch-on the LCD backlight. The setBacklightPin has to be called before setting the backlight for this method to work.

See also

setBacklightPin.

virtual void LCD::begin ( uint8_t  cols, uint8_t  rows, uint8_t  charsize = LCD_5x8DOTS  )

virtualinherited

LCD initialization. Initializes the LCD to a given size (col, row). This methods initializes the LCD, therefore, it MUST be called prior to using any other method from this class.

This method is abstract, a base implementation is available common to all LCD drivers. Should it not be compatible with some other LCD driver, a derived implementation should be done on the driver specif class.

Parameters

cols[in]	the number of columns that the display has
rows[in]	the number of rows that the display has
charsize[in]	character size, default==LCD_5x8DOTS

Reimplemented in LiquidCrystal_I2C.

void LCD::blink ( )

inherited

Display the cursor of the LCD. Display the blinking LCD cursor. If used in combination with the cursor() function, the result will depend on the particular display.

Parameters

none

void LCD::clear ( )

inherited

Clears the LCD. Clears the LCD screen and positions the cursor in the upper-left corner.

This operation is time consuming for the LCD.

Parameters

none

void Print::clearWriteError ( )

inlineinherited

Clears the last write error.

void LCD::createChar ( uint8_t  location, uint8_t  charmap[]  )

inherited

Creates a custom character for use on the LCD. Create a custom character (glyph) for use on the LCD. Most chipsets only support up to eight characters of 5x8 pixels. Therefore, this methods has been limited to locations (numbered 0 to 7).

The appearance of each custom character is specified by an array of eight bytes, one for each row. The five least significant bits of each byte determine the pixels in that row. To display a custom character on screen, write()/print() its number, i.e. lcd.print (char(x)); // Where x is 0..7.

Parameters

location[in]	LCD memory location of the character to create (0 to 7)
charmap[in]	the bitmap array representing each row of the character.

void LCD::cursor ( )

inherited

Display the LCD cursor. Display the LCD cursor: an underscore (line) at the location where the next character will be written.

Parameters

none

void LCD::display ( )

inherited

Turns on the LCD display. Turns on the LCD display, after it's been turned off with noDisplay(). This will restore the text (and cursor location) that was on the display prior to calling noDisplay().

Parameters

none

int Print::getWriteError ( )

inlineinherited

Gets last error.

Return values

int	Error number of last write error

void LCD::home ( )

inherited

Sets the cursor to the upper-left corner. Positions the cursor in the upper-left of the LCD. That is, use that location in outputting subsequent text to the display. To also clear the display, use the clear() function instead.

This operation is time consuming for the LCD.

Parameters

none

void LCD::leftToRight ( )

inherited

Set the direction for text written to the LCD to left-to-right. Set the direction for text written to the LCD to left-to-right. All subsequent characters written to the display will go from left to right, but does not affect previously-output text.

This is the default configuration.

Parameters

none

void LCD::moveCursorLeft ( )

inherited

Moves the cursor one space to the left.

Parameters

none

void LCD::moveCursorRight ( )

inherited

Moves the cursor one space to the right.

Parameters

none

void LCD::noAutoscroll ( )

inherited

Turns off automatic scrolling of the LCD. Turns off automatic scrolling of the LCD, this is the default configuration of the LCD.

Parameters

none

void LCD::noBacklight ( void  )

inherited

Switch-off the LCD backlight. Switch-off the LCD backlight. The setBacklightPin has to be called before setting the backlight for this method to work.

See also

setBacklightPin.

void LCD::noBlink ( )

inherited

Turns off the blinking of the LCD cursor.

Parameters

none

void LCD::noCursor ( )

inherited

Hides the LCD cursor.

Parameters

none

void LCD::noDisplay ( )

inherited

Turns off the LCD display. Turns off the LCD display, without losing the text currently being displayed on it.

Parameters

none

void LCD::off ( void  )

inherited

Switch off the LCD module. Switch off the LCD module, it will switch off the LCD controller and the backlight. This method has the same effect of calling noDisplay and noBacklight.

See also

display,

backlight

void LCD::on ( void  )

inherited

Switch on the LCD module. Switch on the LCD module, it will switch on the LCD controller and the backlight. This method has the same effect of calling display and backlight.

See also

display,

backlight

size_t Print::print ( char  )

inherited

Prints a single character to output stream.

Return values

size_t

Quantity of characters written to stream

size_t Print::print ( const char  [] )

inherited

Prints a c-string to output stream.

Parameters

char[]

c-string to print

Return values

size_t	Quantity of characters written to output stream
size_t	Quantity of characters written to stream

size_t Print::print ( unsigned  char, int  base = DEC  )

inherited

Prints a number to output stream.

Parameters

unsigned long	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

Parameters

unsigned int	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

Parameters

unsigned char	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

size_t Print::print ( long  , int  base = DEC  )

inherited

Prints a number to output stream.

Parameters

long	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

size_t Print::print ( int  , int  base = DEC  )

inherited

Prints a number to output stream.

Parameters

int	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

size_t Print::print ( double  , int  digits = 2  )

inherited

Prints number to output stream.

Prints a number to output stream.

Parameters

double	Number to print
int	Decimal places to show

Return values

size_t

Quantity of characters written to output stream

Parameters

double	Number to print
digits	The decimal places to print (Default: 2, e.g. 21.35)

Return values

size_t

Quantity of characters written to stream

size_t Print::print ( const Printable &  p )

inherited

Prints a Printable object to output stream.

Parameters

p	Object to print

Return values

size_t

Quantity of characters written to stream

size_t Print::print ( const String &  s )

inherited

Prints a String to output stream.

Parameters

s	String to print

Return values

size_t

Quantity of characters written to stream

size_t Print::printf ( const char *  fmt,   ...  )

inherited

Prints a formatted c-string to output stream.

Parameters

fmt	Pointer to formated c-string to print
...	Parameters for placeholders within formated string

Return values

size_t

Quantity of characters written to stream

Note

Use standard printf placeholders, e.g. d for integer, s for c-string, etc.

size_t Print::println ( void  )

inherited

Prints a newline to output stream.

Parameters

Prints

newline to output stream

Return values

size_t	Quantity of characters written to output stream
size_t	Quantity of characters written to stream

size_t Print::println ( const char  [] )

inherited

Prints a c-string to output stream, appending newline.

Parameters

char[]

c-string to print

Return values

size_t

Quantity of characters written to stream

size_t Print::println ( char  )

inherited

Prints a single character to output stream, appending newline.

Parameters

char	Character to print

Return values

size_t

Quantity of characters written to stream

size_t Print::println ( unsigned  long, int  base = DEC  )

inherited

Prints a number to output stream, appending newline.

Parameters

unsigned char	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

Parameters

unsigned int	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

Parameters

unsigned long	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

size_t Print::println ( int  , int  base = DEC  )

inherited

Prints a number to output stream, appending newline.

Parameters

int	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

size_t Print::println ( long  , int  base = DEC  )

inherited

Prints a number to output stream, appending newline.

Parameters

long	Number to print
base	The base for output (Default: Decimal (base 10))

Return values

size_t

Quantity of characters written to stream

size_t Print::println ( double  , int  digits = 2  )

inherited

Prints a number to output stream, appending newline.

Parameters

double	Number to print
digits	The decimal places to print (Default: 2, e.g. 21.35)

Return values

size_t

Quantity of characters written to stream

size_t Print::println ( const Printable &  p )

inherited

Prints a Printable object to output stream, appending newline.

Parameters

p	Object to print

Return values

size_t

Quantity of characters written to stream

size_t Print::println ( const String &  s )

inherited

Prints a String to output stream, appending newline.

Parameters

s	String to print

Return values

size_t

Quantity of characters written to stream

void LCD::rightToLeft ( )

inherited

Set the direction for text written to the LCD to right-to-left. Set the direction for text written to the LCD to right-to-left. All subsequent characters written to the display will go from right to left, but does not affect previously-output text.

left-to-right is the default configuration.

Parameters

none

void LCD::scrollDisplayLeft ( )

inherited

Scrolls the contents of the display (text and cursor) one space to the left.

Parameters

none

void LCD::scrollDisplayRight ( )

inherited

Scrolls the contents of the display (text and cursor) one space to the right.

Parameters

none

virtual void LiquidCrystal::send ( uint8_t  value, uint8_t  mode  )

virtual

Send a particular value to the LCD. Sends a particular value to the LCD for writing to the LCD or as an LCD command.

Users should never call this method.

Parameters

value

Value to send to the LCD.

Returns

mode LOW - write to the LCD CGRAM, HIGH - write a command to the LCD.

Reimplemented from LCD.

void LiquidCrystal::setBacklight ( uint8_t  value )

virtual

Switch-on/off the LCD backlight. Switch-on/off the LCD backlight. The setBacklightPin has to be called before setting the backlight for this method to work.

See also

setBacklightPin. For dimming control of the backlight, the configuration pin must be a PWM output pin. Dim control is achieved by passing a value from 1 to 255 as a parameter. If the pin configured when calling the setBacklightPin does not support PWM, then: (0) backlight off, (1..255) backlight on.

Parameters

value

backlight value. 0: off, 1..255: dim control of the backlight. For negative logic 255: off, 254..0: dim control.

Reimplemented from LCD.

void LiquidCrystal::setBacklightPin ( uint8_t  pin, t_backlighPol  pol  )

virtual

Sets the pin to control the backlight. Sets the pin in the device to control the backlight.

Parameters

pin	pin assigned to the backlight
pol	backlight pin control polarity (POSITIVE, NEGATIVE).

Reimplemented from LCD.

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

inherited

Position the LCD cursor. Sets the position of the LCD cursor. Set the location at which subsequent text written to the LCD will be displayed.

Parameters

col[in]	LCD column
row[in]	LCD row - line.

size_t Print::write ( const char *  str )

inlineinherited

Writes a c-string to output stream.

Parameters

str	Pointer to c-string

Return values

size_t

Quantity of characters written to stream

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

virtualinherited

Writes characters from a buffer to output stream.

Parameters

buffer	Pointer to character buffer
size	Quantity of characters to write

Return values

size_t

Quantity of characters written to stream

Reimplemented in MemoryDataStream, and TwoWire.

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

inlineinherited

Writes characters from a buffer to output stream.

Parameters

buffer	Pointer to character buffer
size	Quantity of characters to write

Return values

size_t

Quantity of characters written to stream

virtual void LCD::write ( uint8_t  value )

virtualinherited

Writes to the LCD. This method writes character to the LCD in the current cursor position.

This is the virtual write method, implemented in the Print class, therefore all Print class methods will end up calling this method.

Parameters

value[in]

Value to write to the LCD.

Implements Print.