Data Sheet

72 : circuit 4a
NEW COMPONENTS
CHARACTER LIQUID CRYSTAL
DISPLAY (LCD): Designed to show a
grid of letters, numbers and other special
characters, LCDs are great for printing
data and showing values. When current
is applied to this special kind of crystal,
it turns opaque. This is used in a lot of
calculators, watches and simple displays.
Adding an LCD to your project will make it
super portable and allow you to integrate
up to 32 characters (16x2) of information.
NEW CONCEPTS
CONTRAST: Pin 3 on the LCD controls
the contrast and brightness of the LCD.
Using a simple voltage divider with
a potentiometer, the contrast can be
adjusted. As you rotate the knob on the
potentiometer, you should notice that the
screen will get brighter or darker and that
the characters become more visible or
less visible. The contrast of LCDs is highly
dependent on factors such as temperature
and the voltage used to power them. Thus,
external contrast knobs are needed for
displays that cannot automatically account
for temperature and voltage changes.
PIXELS: If you look closely at the
characters on the LCD, you will notice
that they are actually made up of lots of
little squares. These little squares are
called pixels. The size of displays is often
represented in pixels. Pixels make up
character space, which is the number of
pixels in which a character can exist.
Here is a capital letter B as
created in pixels. The
character space in this
example is 6 pixels x 8 pixels.
Circuit 4A: LCD
“Hello, World!”
Printing “Hello, world!” is usually the first
thing that programming tutorials will have
you do in a new language. This guide starts
by blinking an LED, but now we’re going
to print out real text using a Liquid Crystal
Display (LCD).
YOU
NEED
LCD DISPLAY POTENTIOMETER 16 JUMPER WIRES