TUTORIAL
Raspberry Pi displays
ADAFRUIT £14 pimoroni.comPIMORONI £95.10 pimoroni.comRASPBERRY PI £60 pimoroni.comPiOLED HDMI 10”
Screen
Official Raspberry Pi
7” Touchscreen
If clarity is an important feature, and you don’t mind a
smaller display, OLED (Organic LED) is becoming more
affordable. This technology offers superior colour
reproduction and much higher contrast than other
display systems. OLED is starting to make its way into
mobile phones and some televisions, but it remains
expensive. However, small monochrome OLED screens
can now be added to Raspberry Pi models starting at
just £15. These are ideal if you want a razor-sharp but
very small screen to display more complex information.
There are many OLED HATs on the market, some
even featuring full colour, but they typically only go up
to about 7” in size. The Adafruit PiOLED featured here
is a tiny 128×32 display that slips over six GPIO pins to
use I^2 C for the display, leaving lots of pins to play with.
The provided Python library makes it easy to display
data or create animations (it has a refresh rate of
30 fps). The OLEDs used will start to dim after about
1000 hours of use, so make use of screen blanking!It may seem a bit obvious to mention HDMI here, but it is, after all,
the de facto standard for Raspberry Pi displays, at least on
desktops. HDMI comes in a range of resolutions. It’s most famous
for high-definition screens, but you can also get smaller ones.
Also of use is its ability to carry 5.1 audio as well, something
nothing else here can do. HDMI is directly compatible with the
older DVI-D standard, which means that an older monitor can
often be picked up cheaply. You just need a £1 adapter.
Possibly of most interest to makers are the ‘guts’ HDMI kits
available. This 10” panel is sold by Pimoroni and is used in the
firm’s famous Picade kit. If you’re building an arcade console,
kiosk, or another type of information display, this is a great and
simple way to get up and running.Moving on to more common displays, we come to Raspberry Pi’s
very own 7” touchscreen. It’s been around for a few years and
has become a firm favourite in the community as a reliable,
high-quality product. The touchscreen is a monitor capable of an
800×480 pixel display. Two things separate this display from the
others featured here. First, it uses the DSI interface found on all
Raspberry Pi models, so no GPIO sacrifice bar some for power
and a couple of GPIO pins for the other unique feature. This, as
you’ve probably guessed from the name, is a touchscreen,
which makes it perfect for interactive applications. By default, it
acts as a mouse pointer, so installation is literally connecting the
screen and booting as Raspbian has full support built-in.
Being an ‘official’ product, there are a lot of third-party
accessories available, including cases and stands in a range of
sizes and colours. The touchscreen makes this display perfect
for control panels, bright colourful infographics, and even more
advanced applications like kiosks or booking systems.Right
This official screen
combines a beautiful
compact display with
touch capabilityRight
HDMI offers the
widest selection and
larger sizes, but at
a price
Left
OLED offers crisp
images in a variety
of sizes, but can
get expensiveDISPLAY
LED
The most basic
type, LEDs are
arranged either
in a matrix or
into seven-
segment
characters.TFT
Thin-film-
transistor
liquid-crystal
displays are the
most common
for older and
lower-cost
monitors.IPS
In-plane
switching
renders a very
high-quality
display with a
much wider
viewing angle
than TFT.OLED
A modern
display
technology that
gives sharp
displays with
better contrast
than IPS. Can be
expensive with a
shorter life-span
than other
options, so tends
to be available
in smaller sizes.TYPES