HackSpace – September 2019

FIELD TEST

he Pimoroni Keybow is an

easy-to-build mini mechanical

keyboard kit that doesn’t require

any soldering. It’s powered by

Raspberry Pi and includes twelve

beautifully illuminated keys.

You can customise the inputs with a variety of

macros, or just use as a simple keyboard.

Clicky or non-clicky is really the only decision you’ll

need to make when you pick up the Keybow kit. And

unlike many other kits or shields, this really includes

everything – OK, almost everything – you need to get

up and running, even a Raspberry Pi Zero WH. The

only additional item you will need is an SD card,

which you most likely have already. The quality of the

keys and PCB is really good, which is what we expect

from any Pimoroni kit. If you want a self-contained

mini keyboard, this is it. And if you are looking for

something a bit smaller, check out Pimoroni’s 3-key

Keybow kit. It’s just as good as the 12-key, but a bit

less expensive and a lot smaller. It’s a great way to

get user input in a small form factor.

T

PIMORONI $60 shop.pimoroni.com ADAFRUIT $ 9.95 adafruit.com

Hackable mini keypads

he Trellis driver PCB assembly

from Adafruit is an open-source

backlight keypad driver system.

It’s really easy to use, thanks to an

extensive tutorial from Adafruit,

and highly customisable. This

Trellis PCB is made to match the Adafruit 4×4

elastomer keypad and has areas in the centre of

each button for customising with 3 mm LEDs.

You will need a microcontroller to control the

Trellis, as the circuitry on the board only handles the

background key presses and LED lighting of the tile.

Any Arduino, or similar microcontroller, can handle

reading of the key inputs and configuring the LEDs.

Our favourite part about the Trellis is its ability to be

expanded and be customised. Each Trellis PCB has

an I^2 C-controlled LED sequencer and keypad reader

already on it. The on-board chip can control all of its

16 LEDs individually. The same circuitry reads any key

presses. You can connect up to eight PCBs together

via their edge connectors. Each board will share the

same power, ground, interrupt, and I^2 C clock and

data pins. This makes building a huge 128-button

matrix really fun and easy! Just remember to pick

up the required matching membrane and LEDs.

T

Keybow 12-key Kit vs

Adafruit Trellis Monochrome Driver

Pimoroni Keybow

A great solution

for adding keyed

input to your

Raspberry Pi.

Adafruit Trellis

Customisable,

affordable, and

extensible.

10

10

VERDICT

/ 10

/ 10

Below

A really well-made

and complete kit

Below

Build and modify

the Trellis however

you’d like