Review
(^182) The Official Raspberry Pi Projects Book raspberrypi.org/magpi
Swipe,
tap or flick
your wrist to
control your
Raspberry Pi
Pi Supply
Maker
Says
FLICK H AT
hat could be cooler than
triggering actions with a
mere wave of your hand?
The Flick HAT allows you do this,
and more. The Flick HAT is one of
three 3D gesture-tracking boards
from Pi Supply – there’s also a
smaller Pi Zero version, and a
larger standalone pre-soldered
board with jumper leads to connect
it to the Pi’s GPIO header.
After securing the Flick HAT
to the top of the Pi with the
nylon nuts, bolts and spacers
supplied, and then using a single-
line installer for the software,
it’s ready to use.
While we’re still awaiting a
full Python API, a few example
programs are supplied. The most
basic of these shows the X, Y and
Z values as you move your hand
above the board, and it works
best when you use a downward-
pointing finger. While the blurb
claims a vertical range of up to
15 cm, in our tests we typically
achieved 5-7 cm. This distance will
depend on the surroundings, and
how conductive you are.
As well as tracking 3D positions,
the board reads gestures including
swipes (left-right and up-down),
and ‘airwheel’, which involves
rotating your finger in mid-air.
This is ideal for an audio volume
control, as used in the volctrl
demo. Among many other uses,
the swiping actions would be
suitable for controlling a slideshow
presentation – something covered
in The MagPi magazine previously,
using the rival Pimoroni Skywriter
HAT (magpi.cc/1PLLYMt).
The Skywriter and the Flick are
based on the same MGC3130 3D
tracking chip. Not surprisingly,
their performance is very similar.
The chip reads up to 200 positions
per second, enabling it to reliably
detect simple gestures. Like the
Skywriter, the Flick also senses
touch – in its centre and on the
four edges – so it’s a versatile input
device that could prove useful for
countless projects.
Interestingly, it even works with
the Skywriter Python library, from
which the Flick library is derived.
We were therefore able to use the
Skywriter software examples,
including a fun theremin synth.
One advantage of the Flick HAT
is the availability of optional cases
for all three models. The cases use
a non-conductive surface, which
does not interfere with the Flick’s
ability to track gestures.
One of a trio of 3D gesture-tracking boards for Raspberry Pi computers
W
SKYWRITER
HAT
Based on the
same chip
as the Flick,
Pimoroni’s
3D gesture-
tracking board
boasts similar
performance.
There’s also an
XL breakout
version.
magpi.cc/1OAPeHb
Related
£16 / $17
FLICK HAT
magpi.cc/2toNhLG
£20 /$26
Last word
The performance of the Flick HAT is very similar to that of the
Skywriter HAT, but the Flick offers an optional snug-fitting case,
as do the other Flick models. Communicating with the Pi via I^2 C,
the Flick only uses a small number of GPIO pins. With the ability to
detect a wide range of gestures and touches, it would be a useful
input device for many projects.