LiquidCrystal
Library
Function
Description
Creates a variable of
type LiquidCrystal
. The display can be controlled using 4
or 8 data lines. If the former, omit
the pin numbers for d0 to d3 and leave those lines unconnected.
The RW pin can be tied to ground instead of
connected to a pin on the Arduino; if
so, omit it from this function's parameters.
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, d1, d2, d3, d4,
d5, d6, 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).
Example
#include <LiquidCrystal.h>
LiquidCrystal lcd
(
12
,
11
,
10
,
5
,
4
,
3
,
2
)
;
void
setup
(
)
{
lcd. begin
(
16
,
1
)
;
lcd.
print
(
"hello, world!"
)
;
}
void
loop
(
)
{
}
Description
Initializes the interface to the LCD
screen, and specifies the dimensions (width and height) of the display.
begin()
needs to be called before any other LCD library commands.
Syntax
lcd
.begin(cols, rows)
Parameters
lcd: a variable of
type LiquidCrystal
cols: the number of
columns that the display has
rows: the number of
rows that the display has
Description
Clears the LCD screen and positions the
cursor in the upper-left corner.
Syntax
lcd .clear()
Parameters
lcd: a variable of type
LiquidCrystal
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
lcd: a variable of type
LiquidCrystal
Description
Position the LCD cursor;
that is, set the location at which subsequent
text written to the LCD will be displayed.
Syntax
lcd
.setCursor(col, row)
Parameters
lcd: a variable of
type LiquidCrystal
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)
Description
Write a character to the LCD.
Syntax
lcd
.write(data)
Parameters
lcd: a variable of
type LiquidCrystal
data: the character to
write to the display
Returns
byte
write() will return the number of bytes written, though reading that
number is optional
Example
#include <LiquidCrystal.h>
LiquidCrystal lcd
(
12
,
11
,
10
,
5
,
4
,
3
,
2
)
;
void
setup
(
)
{
Serial .
begin
(
9600
)
;
}
void
loop
(
)
{
if
(
Serial .
available
(
)
)
{
lcd.
write
(
Serial .
read
(
)
)
;
}
}
Description
Prints text to the LCD.
Syntax
lcd
.print(data)
lcd
.print(data, BASE)
Parameters
lcd: a variable of
type LiquidCrystal
data: the data to
print (char, byte, int, long, or string)
BASE (optional): the
base in which to print numbers: BIN for binary (base 2), DEC for decimal
(base 10), OCT for octal (base 8), HEX for hexadecimal (base 16).
Returns
byte
print() will return the number of bytes
written, though reading that number is optional
Example
#include <LiquidCrystal.h>
LiquidCrystal lcd
(
12
,
11
,
10
,
5
,
4
,
3
,
2
)
;
void
setup
(
)
{
lcd. print
(
"hello, world!"
)
;
}
void
loop
(
)
{
}
Description
Display the LCD cursor: an underscore
(line) at the position to which the next character will be written.
Syntax
lcd .cursor()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Hides the LCD cursor.
Syntax
lcd
.noCursor()
Parameters
lcd: a variable of type
LiquidCrystal
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
lcd: a variable of type
LiquidCrystal
Description
Turns off the blinking LCD cursor.
Syntax
lcd
.noBlink()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Turns on the LCD display, after it's been
turned off with
noDisplay (). This will restore the
text (and cursor) that was on the display.
Syntax
lcd
.display()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Turns off the LCD display, without losing
the text currently shown on it.
Syntax
lcd
.noDisplay()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Scrolls the contents of the display (text
and cursor) one space to the left.
Syntax
lcd
.scrollDisplayLeft()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Scrolls the contents of the display (text
and cursor) one space to the right.
Syntax
lcd
.scrollDisplayRight()
Parameters
lcd: a variable of type
LiquidCrystal
Description
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.
Syntax
lcd
.autoscroll()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Turns off automatic scrolling of the LCD.
Syntax
lcd
.noAutoscroll()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Set the direction for text written to the
LCD to left-to-right, the default. This
means that subsequent characters written to the display will go from
left to right, but does not affect previously-output text.
Syntax
lcd
.leftToRight()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Set the direction for text written to the
LCD to right-to-left (the default is left-to-right).
This means that subsequent characters written
to the display will go from right to left, but does not affect
previously-output text.
Syntax
lcd
.rightToLeft()
Parameters
lcd: a variable of type
LiquidCrystal
Description
Create a custom
character (gylph) for use on the LCD.
Up to eight characters of 5x8 pixels are supported (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 the screen,
write () its number.
NB : When referencing custom character
"0", if it is not in a variable, you need to cast it as a byte,
otherwise the compiler throws an error. See the example
below.
Syntax
lcd
.createChar(num, data)
Parameters
lcd: a variable of
type LiquidCrystal
num: which character
to create (0 to 7)
data: the character's
pixel data
Example
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
byte smiley[8] = {
B00000,
B10001,
B00000,
B00000,
B10001,
B01110,
B00000,
};
void setup() {
lcd.createChar(0, smiley);
lcd.begin(16, 2);
lcd.write(byte(0));
}
void loop() {}
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