Liquid Crystal Display (LiquidCrystal Class)

This library allows the control of 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, describe #include <liquidcrystal.h> and generate an instance like LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2).

Constructor for LiquidCrystal

Description: Generates 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 Arduino pin that is connected to the RS pin on the LCD
rw: The number of the Arduino pin that is connected to the RW pin on the LCD (optional)
enable: The number of the Arduino pin that is connected to the enable pin on the LCD
d0～d7: The numbers of the Arduino pins that are connected to the corresponding data pins on the LCD. d0, d1, d2, and d3 are optional; if omitted, the LCD will be controlled using only the four data lines (d4, d5, d6, d7).

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 and positions the cursor in the upper-left corner.
Syntax: lcd.clear
Parameters: None
Returns: None

home

Description: 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.
Syntax: lcd.home
Parameters: None
Returns: None

setCursor

Description: Position the LCD cursor. That is, set the location at which subsequent text written to the LCD will be displayed.
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)
row: The row at which to position the cursor (with 0 being the first row)
Returns: None

write

Description: Write 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 text to the LCD.
Syntax: lcd.print(val)
Parameters: val: The data to print (char, byte, int, long, or string)
Returns: None

cursor

Description: Display the LCD cursor: An underscore (line) at the position to which the next character will be written.
Syntax: lcd.cursor()
Parameters: None
Returns: None

noCursor

Description: Hides the LCD cursor.
Syntax: lcd.noCursor()
Parameters: None
Returns: None

blink

Description: Display the blinking LCD cursor. If used in combination with the cursor() function, the result will depend on the particular display.
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(). This will restore the text (and cursor) that was on the display.
Syntax: lcd.display()
Parameters: None
Returns: None

noDisplay

Description: Turns off the LCD display, without losing the text currently shown on it.
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

Example

This example displays "COTTON" on an LCD with three control lines and four data lines.


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

Liquid Crystal Display (LiquidCrystal Class)

Basic Library

Standard Library