Liquid Crystal Display (LiquidCrystal Class)

Basic Library

Digital I/O
Analog I/O
Advanced I/O
Time
Math
Trigonometry
Random Numbers
Bits and Bytes
Interrupts
Serial Comm.

Standard Library

Servo Motor
Character LCD
SPI
I²C (Wire)
SD Card
SD (File Operations)
Periodic Operation
Clock (RTC)

Liquid Crystal Display (LiquidCrystal Class)

This library allows an Arduino board to control Liquid Crystal Displays (LCDs) based on the Hitachi HD44780 (or a compatible) chip set, which is found on most text-based LCDs. The library works with either 4- or 8-bit mode (i.e. using 4 or 8 data lines in addition to the rs, enable, and optionally, the rw control lines).

To use this library, specify #include <liquidcrystal.h>.

LiquidCrystal Constructor

Description

Generates an object of LiquidCrystal.

Syntax

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

Parameters

rs: The number of the pin that is connected to the RS pin on the LCD
rw: The number of the pin that is connected to the RW pin on the LCD
enable: The number of the pin that is connected to the enable pin on the LCD
d0 to d7: The numbers of the pins that are connected to the corresponding data pins on the LCD.

begin

Description

Specifies the dimensions (width and height) of the display.

Syntax

lcd.begin(int cols, int rows)

Parameters

cols: The number of columns that the display has
rows: The number of rows that the display has

Returns

None

clear

Description

Clears the LCD screen.

Syntax

lcd.clear

Parameters

None

Returns

None

home

Description

Returns the LCD cursor in the home position.

Syntax

lcd.home

Parameters

None

Returns

None

setCursor

Description

Moves the LCD cursor.

Syntax

lcd.setCursor(unsigned char col, unsigned char row)

Parameters

col: The column at which to position the cursor (with 0 being the first column (left edge))
row: The row at which to position the cursor (with 0 being the first row)

Returns

None

write

Description

Writes a character to the LCD.

Syntax

lcd.write(unsigned char data)

Parameters

data: The character to write to the display

Returns

None

print

Description

Prints character strings or number sequences to the LCD.

Syntax

lcd.print(val)

Parameters

val: Character string or value

Returns

None

cursor

Description

Displays the LCD cursor.

Syntax

lcd.cursor()

Parameters

None

Returns

None

noCursor

Description

Hides the LCD cursor.

Syntax

lcd.noCursor()

Parameters

None

Returns

None

blink

Description

Displays the blinking LCD cursor.

Syntax

lcd.blink()

Parameters

None

Returns

None

noBlink

Description

Turns off the blinking LCD cursor.

Syntax

lcd.noBlink()

Parameters

None

Returns

None

display

Description

Turns on the LCD display, after it has been turned off with noDisplay().

Syntax

lcd.display()

Parameters

None

Returns

None

noDisplay

Description

Turns off the LCD display.

Syntax

lcd.noDisplay()

Parameters

None

Returns

None

scrollDisplayLeft

Description

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

Syntax

lcd.scrollDisplayLeft()

Parameters

None

Returns

None

scrollDisplayRight

Description

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

Syntax

lcd.scrollDisplayRight()

Parameters

None

Returns

None

autoscroll

Description

Turns on automatic scrolling of the LCD.

Syntax

lcd.autoscroll()

Parameters

None

Returns

None

noAutoscroll

Description

Turns off automatic scrolling of the LCD.

Syntax

lcd.noAutoscroll()

Parameters

None

Returns

None

leftToRight

Description

Set the direction for text written to the LCD to left-to-right, the default.

Syntax

lcd.leftToRight()

Parameters

None

Returns

None

rightToLeft

Description

Set the direction for text written to the LCD to right-to-left (the default is left-to-right).

Syntax

lcd.rightToLeft()

Parameters

None

Returns

None

Sample Program

This sample shows Liquid Crystal Display on GR-CITRUS using 3 control lines and 4 data lines.

#include <Arduino.h>
#include <liquidcrystal.h>
 
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);
 
void setup()
{
  lcd.begin(16,2); //16x2 lcd initial
  lcd.print("CITRUS");
}
 
void loop() {}