New year’s disco ball: because “disco icosahedron” just doesn’t have the same ring to it

“Simplify, simplify, simplify.” — Thoreau

“One ‘simplify’ would have sufficed.” — Emerson

With a nifty construction method settled upon, it was time to decide on a polygonal shape for our “new year’s disco ball.” This seemed like a solved problem — geodesic domes are sufficiently popular that you can find kits and calculators all over the internet — but we soon hit a snag: while at first glance these domes appear to be comprised of many identical triangles, it turns out there are actually very subtle variations throughout. This is not a technical problem at all; it could certainly be done, but it fails our Annoying Test. Each piece must be aligned with exactly the right neighbors and turned exactly the right way. Now repeat the process dozens or hundreds of times without a single mistake. No.

So, Plan B, we looked at Archimedian solids. Many of these polyhedra achieve a nice ball-like shape while being comprised of just two or three types of regular polygons. The truncated icosahedron (colloquially sometimes labeled a “soccer ball” or “Buckyball”) was especially pleasing:

On its own, the shape is now pretty easy to build. But when it came time to think about lighting this up, even this shape proved just a bit too complex. Here’s why:

If we just wanted to jam LEDs in there and blink them at random, that would be simple and we could call it done. But that’s…just…lacking something. We’d really like to be able to address these LEDs with order and purpose…top to bottom, around the circumference, you name it. And again, there’s nothing technically barring us from doing that with this shape. It’s simply a matter of not wanting to alienate readers and kit-builders with limited patience. You see, to keep track of their positions, every single LED would need to be installed in a specific place, in a specific sequence, somewhere on this map:

Not fun to try to explain…or read…in instructions. So we’ll back off one more step and consider the Platonic solids, which are each comprised of a single repeating regular polygon. Gamers are well familiar with them:

(Please ignore the d10 and imagine a d6 in its place!)

The dodecahedron (in blue) and icosahedron (red) are both vaguely round…ish. We settled on the icosahedron, comprised of 20 equilateral triangles, because the math is simpler, and it spreads out nicely as a flat map:

Much easier for indicating where will LEDs go! And a quick ugly prototype confirms that the LEDs will fit:

So, after that whole digression, we’ve come full circle to use one of the original cable-tie assembly shapes we had already looked at!

We’ll make the finished ball (yes, we’re still calling it a “ball,” despite its obvious polygonality) in mirrored acrylic for added bling factor. With 20 faces, and six LEDs per face, that’s 120 LED pixels total. We’ll need those figures later when coming up with a power supply…

Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here:

Join Adafruit on Mastodon

Adafruit is on Mastodon, join in!

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 36,000+ makers on Adafruit’s Discord channels and be part of the community!

CircuitPython – The easiest way to program microcontrollers –

Maker Business — “Packaging” chips in the US

Wearables — Enclosures help fight body humidity in costumes

Electronics — Transformers: More than meets the eye!

Python for Microcontrollers — Python on Microcontrollers Newsletter: Silicon Labs introduces CircuitPython support, and more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Guardian Robot, Weather-wise Umbrella Stand, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — #NewProds 7/19/23 Feat. Adafruit Matrix Portal S3 CircuitPython Powered Internet Display!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at !

1 Comment

  1. OK, I am in full lust of this..

Sorry, the comment form is closed at this time.