KINDS OF BUTTONS
Cap
Silicone rubber
membrane
with embedded
conductive material
Conductive ink
“fingers”
CONDUCTIVE RUBBER BUTTON
PANEL-MOUN T BUTTON
Rarely found in consumer electronics
but a favorite with hobbyists. These
switches are the most versatile but
also the most expensive and, relative to
tactile and rubber switches, the most
delicate.
Pros: Easy to use, available in many
different configurations, can handle
high current, very easy to hack.
Cons: Much more expensive than other
kinds of buttons. More moving parts,
therefore more delicate.
CAUTION: As always, only work with battery-powered electronics or circuits that are powered with
a wall wart adapter. Don’t tinker with circuits that plug
directly into the wall unless you know what you’re doing
and are qualified to work with deadly voltage levels.
is that they are. That means anywhere there’s
a button, you can replace it with another button, a sensor, a relay, or any other means of
passing and breaking current flow. As long as
the nodes connect and disconnect, it’ll work.
Just make sure the button you use can
handle the electrical current that will pass
through it. This article only covers low-current
circuits and buttons.
Illustration by Peter Edwards
Let’s Hack Some Buttons
I like making music, so I decided to hack the
buttons in a bunch of musical toys so that I
could control them all with a sequencer.
I selected 3 Casio keyboards — one for the
drumbeat and 2 for the melody — and 3 voice
memo recorders to sample and play back the
sound from the keyboards, introducing all
kinds of interesting variables into the music.
MATERIALS AND TOOLS
Soldering iron, solder, and insulated wire
NPN transistors general purpose
Resistors, 10kΩ (optional) and 100kΩ
Arduino microcontroller Maker Shed part #MKSP4,
makershed.com, $35
Breadboard
Multimeter with continuity tester
Mini screwdrivers for opening electronic devices
1. Identify the buttons you want to hack.
Let’s look at the Casio SA- 38. This keyboard
is useful because it has 5 big drum buttons
(Figure A, following page). I can hack these
and sequence them to make drumbeats.
2. Open it up.
Once you open up the keyboard, you’ll see
3 circuit boards (Figure B). The green board
handles power and audio. Underneath it is a
brown board with a big chip on it. This chip is
the main brain of the keyboard, so I’ll call this
the control board. This board and the third
board alongside it hold all the conductive rubber pushbuttons. The control board has the
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