The Official Raspberry Pi Projects Book - Projects_Book_v4

Review

(^180) The Official Raspberry Pi Projects Book raspberrypi.org/magpi
A
compact
display, with
buttons and
a joystick
Adafruit
Maker
Says
128×64 OLED
BONNET
ooking for a low-power
yet bright mini display for
your Pi project? Adafruit’s
miniature OLED screen could
well fit the bill. An OLED (organic
light-emitting diode) display offers
high contrast combined with a
low power draw, since it doesn’t
require a backlight.
While numerous OLED screens
are available, including a range
from Adafruit itself, most require
you to wire them up manually
to the Raspberry Pi (or whatever
device you’re using). The Pi Zero-
sized OLED Bonnet takes the hassle
out of connection: pre-assembled
with a female header, it simply
slots onto the Pi’s GPIO pins.
Available from Pimoroni in
the UK, the OLED Bonnet is the
big sibling of the 128×32 PiOLED
(magpi.cc/2xAq7po), doubling the
latter’s screen area while adding
a mini joystick (four-way plus
central push function) and two
buttons. This would make it ideal
for use as a mini menu system in,
for example, a music player.
While the screen is monochrome

• white on black – and obviously
  too low-res to use as a main Pi
  display, its high contrast enables
  it to show text with great clarity.
  Any standard TTF font can be used,
  and one of the Python examples
  downloaded after cloning the
  relevant GitHub repo is an old-
  school sine-wave scrolling text
  demo. Basic images, which may be
  converted to bitmaps and resized
  via PIL, can also be displayed.
  Unlike an E ink screen, the
  OLED Bonnet is even able to
  handle basic animations. While
  the frame rate is rather sluggish
  by default, it can be speeded up to
  about 15 fps by raising the I^2 C core
  baud rate to 1MHz in the Raspberry
  Pi’s /boot/config.txt file.

As well as two GPIO pins for I^2 C

communication with the Pi, the

OLED Bonnet uses seven others

for joystick and button inputs.

That still leaves plenty of GPIO

pins available for use in projects,

although due to the full-size

female header, you’ll need to

break them out using something

like a Pico HAT Hacker.

Last word

With its high contrast and

clarity, the OLED Bonnet is

ideal as a mini status display

or – taking advantage of the

joystick and buttons – menu

system. The screen’s low

power draw (around 40 mA on

average) is also an advantage

for portable projects using

battery power.

A high-contrast mini OLED display, complete with controls

L

SCROLL

PHAT HD

Packing 17×7

white pixels,

with full PWM

brightness

control, this

display is ideal

for scrolling text

messages.

magpi.cc/2wShYcf

Related

£12 / $13

128×64 OLED BONNET

magpi.cc/2xzuC3h

£20 / $22