The Official Raspberry Pi Projects Book - Projects_Book_v4

Review

raspberrypi.org/magpi The Official Raspberry Pi Projects Book 181

Six touch-

sensitive

buttons

to use for

whatever

your heart

desires

Pimoroni

Maker

Says

TOUCH PHAT

eed to add some button

controls to a project you’re

making? Pimoroni’s

Touch pHAT makes it easy. This Pi

Zero-sized board boasts six touch-

sensitive buttons which light up

when pressed; white LEDs located

on the underside produce a yellow/

green glow through the translucent

board sections. While the buttons

are marked A, B, C, D, Back, and

Enter (and referred to as such when

coding), each has a large white area

for custom labelling with a sticker

or dry-wipe marker.

The pHAT is supplied with a

female header which you’ll need

to solder in place. While the board

has a Pi Zero form factor, it can be

used with any 40-pin Pi model.

Equipped with a CAP1166 capacitive

touch and LED driver chip, it

uses I^2 C for communication, and

therefore requires only two GPIO

pins. No standoffs are supplied,

but you may want to add some to

keep the pHAT rock steady on top

of the Pi as you press the buttons.

Alternatively, you could combine

it with Pimoroni’s neat-looking

Pibow Zero W case.

Like most Pimoroni add-ons,

the Touch pHAT has its own

Python library, which is easily

installed – along with any missing

dependencies – using a single

Terminal command. A couple of

examples are supplied: a simple

button-press demo and a GUI app

launcher. The code syntax is simple

enough, using on_press and

on_release events to register the

relevant touch actions. It’s then

completely up to you as to what

these will trigger. Possible uses

for the Touch pHAT include as a

control panel for a robot, a remote

control for home automation, a

drum machine / mini piano, and

a Simon game.

Most importantly, the buttons

are very responsive to touch

and will stay triggered/lit until

released; you can press as many

as you like simultaneously,

too. They can even be activated

through a thin transparent

layer if needed. Note that if you

wanted to attach alligator clips

to the buttons to attach remote

triggers (such as pieces of fruit),

you’d have to scrape down to the

copper on each button to make the

connection work.

Last word

The Touch pHAT makes it a lot

easier to add input buttons

to projects, instead of having

to wire up push-buttons

individually. What you use it

for is completely up to you, but

the touch-sensitive buttons

are really responsive and the

light-up effect is a nice bonus.

An easy way to add button inputs to your projects

N

RAINBOW

HAT

Compatible with

Android Things

and Python,

this full-size

HAT features

three capacitive

buttons, a four-

digit display,

LEDs, buzzer,

and sensor.

magpi.cc/2lX1r6h

Related

£24 / $26

TOUCH PHAT

magpi.cc/2pafoP9

£8 /$9