HackSpace_-_April_2020

3D printing, I had my fair share of print

failures, but I tried to make use of failed

prints too by patching them up and using

them to test while the next version printed.

Since this project would need WiFi

connectivity, I switched from an Uno to an

ESP8266-based Wemos D1 Mini. These

boards are small, powerful, include WiFi, and

are relatively cheap. Their main downside is a

limited amount of GPIO, but for this project,

I only needed one pin. A bonus feature of

LENS

least-known or most difficult feature first
and try the simplest prototype. Using this
approach, you can find out quickly whether
something is feasible or not rather than
spending a lot of time on up-front design
only to discover it won’t work later on. I
often make things out of cardboard or other
scrap so that I can quickly try ideas.
For this project, the aspect I needed to
explore was how good it would actually
look. In my head, I had an image of a bin
glowing a nice evenly-lit colour, but would
this translate to reality, or would it just look
like a few LEDs inside a box? Luckily for me,
there was already a bin model on
Thingiverse – it wasn’t the right size or
appearance for what I wanted, but good
enough to test with. I printed it using white
PLA, which was perfect for diffusing while
still allowing a lot of light to transmit
through. I soldered up a strand of NeoPixels
and breadboarded it up to an Arduino to try
out. Success, of sorts – the PLA produced
just the right kind of glow, but to produce
multiple colours, I would require more than
just a hollow bin shape.
I used Blender to start constructing my
own wheelie bin from scratch; now I could
tailor it to exactly the right dimensions,

include a port for the USB connector, and

include a light baffle structure to help shape

the lighting. Iteration was the name of

the game now, printing multiple versions

until I was happy with how the electronics

would fit inside, and perfecting the lighting

and finish.

Printing a single bin in its entirety at good

quality took seven hours, which is a long

time to wait to get feedback. So, one

technique I used was to only print part of

the bin, depending on which aspect I was

changing. For example, I might just print the

bottom quarter because it’s enough to check

for electronics fit. Like everyone who does

Above

Designing our notifier

Below

If only we knew when to take these bins out

The idea of a bin-shaped lamp intrigued

me; it would check the council’s data and

change to the colour of the due bin