Review
raspberrypi.org/magpi The Official Raspberry Pi Projects Book 183
A low-
energy, high-
falutin, red/
black/white
electronic
paper display
for your Pi!
PimoroniMaker
SaysINKY PHAT
INKY PHAT
ith the ability to display text
and images that remain
on screen without using
a power supply, E Ink displays are
ideal for saving precious battery
life in portable projects. They’re
also much easier to view in bright
sunlight than conventional screens.
Until now, Pi E Ink displays have
been black and white – but the tri-
colour Inky pHAT injects a bright
shade of red or yellow into the mix.
This certainly adds a dash of extra
interest to images, such as the logo
shown on the display when you
unpack your pHAT.
Unlike the rival PaPiRus Zero,
the Inky pHAT comes fully
assembled, with the E Ink screen
already mounted and connected to
the board via a small ribbon cable.
This saves fiddling about with a
thin and fragile screen, although
you still have to take care not to
press on it when mounting the
pHAT on the Pi’s GPIO pins.While the Inky pHAT has a
Zero form factor, it’ll happily
work with any 40-pin Pi model.
Communicating via SPI, it only
uses six GPIO pins (plus 3 V and
5 V power). If you wanted to
locate the screen away from the
Pi, however, you’d need to use
something like a Black Hat Hack3r
(magpi.cc/2fqGy0D).
A single Terminal command
installs all the software required.
The Python library comes with a
few helpful examples, including
a calendar and a weather display.
There’s a lot of flashing and
pulsing as the screen refreshes,
the red parts usually appearing
last. While the end result looks
vibrant, the downside is a much
slower refresh time compared
with a monochrome E Ink screen- typically around 15 seconds
vs 1 second or less. The badge
example takes even longer, but
demonstrates the ability for a
partial update, adding text (your
name) to a background image.
The slow refresh rate makes the
Inky pHAT unsuitable for scrolling
text, but static text can easily be
displayed in any installed TrueType
font, using a simple message
function in Python. Images are a
bit trickier, as you need to prepare
them in a special indexed colour
mode, and they must also exactly
match the size of the display
at 212×104 pixels.Add a little more colour to your E Ink display, says Phil King
W
PAPIRUS
ZERO
Available in a
range of sizes,
this black-and-
white E Ink
display has a far
faster refresh
rate, plus push-
buttons to
control what’s
shown on
screen.magpi.cc/2ou5KThRelated
From
£27 / $35magpi.cc/2w1RKow
£22 /$29
Last word
While the slow refresh rate
makes the Inky pHAT unsuitable
for some projects, it does look
far cooler than a standard
monochrome E Ink display. If
you want a low-power, battery-
saving screen with a little more
pizzazz, this is the one to get.