(^62) The Official Raspberry Pi Projects Book raspberrypi.org/magpi
f you’ve ever been to a
fairground and been asked
to ‘step right up’ and ‘test
your strength’, then you may have
found yourself smashing a hammer
against a puck in an attempt to ring
a bell. These so-called Hi Striker
attractions have been popular
Projects SHOWCASE
When Steve Upton was challenged to have a bash at creating a Hi Striker machine,
he hit the ground running and ended up developing two
PI BASH
I
STEVE UPTON
His parents would say he was breaker,
but today he’s more of a maker.
Founder of Makespace (Cambridge)
and creator of lots of amazing projects.
ste5eu.com / @ste5eu
for close to 100 years, but when
Steve Upton based one around an
Arduino, he didn’t realise he’d soon
have a Pi-based hit on his hands.
The idea for building the gaming
machine came from a company
called AJW Distribution, which
had approached the members
of Cambridge’s inventing shed,
Makespace. The firm wanted
something to entice people to its
stand at a forthcoming trade show.
“They wanted it to look like the side
of a building, and use their cladding
and roofing material,” says Steve,
who agreed to the challenge.
New and improved
Having created the machine, which
made lots of cash for charity, Steve
decided to play around with his
design. “I knew it would be great
for Raspberry Pi parties, Jams, and
Maker Faires,” he says. “So I just
had to create another improved
version based on what I’d learnt.”
He was going to call it Pi Striker,
“but I couldn’t write an ‘r’ with the
displays I intended to use for the
scoreboard.” Instead, he named
the new project Pi Bash and,
grabbing a wad of paper, began to
draw up his plans.
Steve knew what he needed to
create the machine based on his
previous experience. He decided to
use the small, inexpensive plug-on
RasPiO Duino board for sensing
and the focused monitoring of
speed. He also used a pressure
sensor which could detect a hit,
a vertical LED strip that would
light up according to how hard the
impact was, some star-shaped
LED strips, and a bell with a relay
controller to produce a satisfying
ding if the player was successful.
He also wanted a mode selector
so that the game could be
t took Steve 24 I
hours to make
It cost £174
in parts from
RS, Pi Hut,
and Pimoroni
The current
highest scorer
is a blacksmith
The frame was
designed using
Autodesk’s
Fusion 360
A refined
version was
produced for a
Maker Faire
Quick
Facts
The bell runs on 12 V. It
can be triggered using
GPIO Zero and a 5 V relay
between the bell and a
12 V power supply
Steve wants to create a
webpage of high scores
and get the machine to
take a photo of each player
The hardest challenge
was the physics involved in
getting the strike to relate
to the height of the lit LEDs
Below Steve built
a full working
version, adding an
element at a time.
This image is an
early prototype