While we’ve
mostly covered
the Raspberry
Pi here in its
role as a computer,
there’s a duality
to it: It’s as much a
hobbyist hardware
platform as it is mini
PC. Thankfully, the Pi
4’s hardware shift has
not affected its GPIO
pins, which are laid out
in the same way as the
whole range, from Pi
Zero up, so the entire
world of Pi HATs is
available to those open
to experimentation.
Whether you want toadd a dedicated LCD,
e-ink, or TFT display,
add arcade control to
your emulation box,
upgrade its audio
output with a dedicated
DAC, or give yourself
a convenient platform
for electronics
tinkering, there’s
something for you.
We wouldn’t call
any HAT absolutely
essential, but
something that adds
an actual hardware
power switch to the
Pi should be high on
your list, particularly
if you’re runningheadless, because
powering down a
Pi by yanking out
the USB connector
is a tremendously
bad idea for your
data. A SHIM (which,
charmingly, stands
for “shove hardware
in the middle”) is a
great choice for this,
because it won’t
interfere with any
HATs you’ve placed on
top of it. Pimoroni’s
OnOff SHIM (around
$8) is a great choice as
long as your case gives
room for you to reach
its small momentarybutton—it does also
offer breakout pins for
a button of your own.
All it takes is a little
one-line software
command to install the
clean shutdown script
and protect your Pi
from data loss.
Of course, you
don’t have to use aSHIM—those pins are
yours to play with. If
you want to write your
own shutdown script,
and wire the right pair
of pins to a button or
switch of your own,
you can.The OnOff SHIM
is an eas y way
to make sure
you power
off properly.©^PIMORONI,^ PLEXServer. It’s not necessarily the
best at transcoding that media, but
it can. Hosting it and streaming it
around your network and beyond
is fully plausible, but you may find
your CPU getting hammered and
the Pi heating up hugely. Thankfully,
at least the most recent version is
happy to work with the Pi 4.
Run sudo apt install apt-
transport-https -y followed by
curl https://downloads.plex.tv/
plex-keys/PlexSign.key | sudo apt-
key add - to grab the Raspberry
Pi PGP key. Then run echo ‘deb
https://downloads.plex.tv/repo/deb
public main’ | sudo tee /etc/apt/
sources.list.d/plexmediaserver.
list to tell your package manager
where to get Plex’s files, sudo apt
update to update its knowledge of
said files, then sudo apt install
plexmediaserver to install it. Once
it’s done, you’ll be able to log in to its
web interface, and get it configured
using localhost:32400 on the Pi, or
substituting “localhost” for your Pi’s
IP address on a remote machine.›› RETRO GAMING I t ’s f a ir to s a y t h a t
the only reason many people own a
Pi at all is RetroPie (http://retropie.
org.uk), the all-in-one package that
pulls together emulator support for
just about every classic system, and
adds a neat front end with which you
can select (legally obtained) ROMs.
Right now, the system image for
RetroPie is built on top of Raspbian
Stretch, an older version of the OSwith no support for the Pi 4, and
RetroPie’s creator specifically notes
that it will not work.
This is a shame, particularly as
that the Pi 4 has the muscle to run
Dreamcast, N64, and PSP games at
close to original speeds, but not all
is lost. You can run emulators such
as RetroArch yourself, or you can
simply install the RetroPie package
(which contains the equivalent of
what’s included in the system image)
on top of Raspbian itself. Execute
sudo apt-get install git lsb-releaseto install some prerequisites, then
use git clone --branch fkms_rpi4
--depth=1 https://github.com/
RetroPie/RetroPie-Setup.git to
download the installation script.
Jump into the directory with cd
RetroPie-Setup , use chmod +x
retropie_setup.sh to tell Linux you
want to execute that file, then run it
with sudo ./retropie_setup.sh.
Alternatively, you can try Lakka,
the official Libretro distro—it’s not
officially released yet, but you can
grab the latest version from http://Plex is basically roll-your-own Netflix, assuming you have a large amount of media.Raspberry Pi 4
42 MAXIMUMPC JAN 2020 maximumpc.com