The MagPi - July 2018

raspberrypi.org/magpi July 2018 31

SEEING WAND Projects

to be robust enough and free to use
for our project.”
The results surprised him in
terms of accuracy and level of
detail: “People, pets, and large
objects seem to be the sweet spot.”

Even when the wand gets it
wrong, the results can be amusing.
“My kids had a lot of fun whenever
something was misidentified, such
as pointing at a toy robot on a table
and having it identified as ‘a small
child on a chair’. Another example
was pointing at our garage with a
sloping roof and being informed
there was ‘a skateboarder coming
down a hill’ – still not sure what it
thought the skateboarder was. My
favourite, though, had to be when
we pointed it at clouds and heard
what sounded like ‘Superman
flying across a blue sky’.”

>STEP-01

Wiring the electronics

Components include a Pi Zero W,

Camera Module, and Speaker

pHAT. Wiring is currently via a mini

breadboard. The device is powered

by a 2200 mAh power cube.

>STEP-02

PVC housing

The electronics are crammed into a PVC

tube. The camera fits into a closet-rod-

supporting end cap and is held in place by

rigid insulation, with its lens up against the

cap’s screw hole.

>STEP-03

Two buttons

The breadboard holds two push-buttons:

one to take a photo of the item you want

to identify, and the other – wired to the

GPIO 03 and GND pins – to turn the Pi

Zero W on and off.

MAKE A MAGIC WAND

As per its original inspiration,

however, the Seeing Wand could

be of serious use to partially

sighted people. “Although there

are smartphone apps that do the

same thing, this could be a less

expensive and more human-

friendly device.”

Fine-tuning

Robert admits that the prototype

wand is a little rough around the

edges. “We have talked about

making improvements both to the

hardware and software. On the

hardware side, we would solder

all wires and buttons, and use a

smaller battery in order to make

it truly palm-sized and thinner

so it could fit as the holding end

of a white (blind) cane. For the

software, we’d like to integrate

A Pi Camera Module is used to take photos of items,

while speech is output through a Speaker pHAT

the text recognition and possibly

language translation services so

signs and printed material could

be read, and the face recognition

service so people could be

identified. Also, as the cognitive

services are not yet perfect, it

would be interesting to ‘poll’

multiple services and determine

which identification is best through

our own cognitive meta-service.”

Even when the wand gets it

wrong, the results can be amusing