Liquid Crystal Display (LiquidCrystal Class)

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() {}