We’re suckers for a good desk toy here at Hackaday, so this 2019 Hackaday Prize entry from [Jack Flynn] certainly caught our eye. The idea is that by using professionally manufactured dual layer PCBs and only surface mount components, you can create a cube that has an LED matrix on each face and all of the electronics hidden within. We’re not entirely sure if there’s any practical application for such a device, but we know we’d certainly like to have one blinking madly away on our shelf regardless.
Before having any of the PCBs manufactured, [Jack] is putting a considerable amount of thought into the design so he doesn’t end up painting himself info a corner (which is of course eight times as bad when you’re building a cube). By importing the PCB files into OnShape, he’s able to “assemble” a virtual representation of the final product to better understand how everything will fit together. He wants to limit the amount of times the cube will need to be pulled apart, so everything from how it will sit in its 3D printed cradle to the placement of breakaway tabs that ensure the internal power switch is accessible are being carefully planned out.
The current design puts the “brains” on the bottom board, with every other panel holding a daisy-chained MAX7219 to drive its own individual 64 LED matrix. Initially the dimensions of the ATmega328p powered cube will be 42 x 42 x 42 mm, with a total of 384 LEDs. Ultimately, [Jack] hopes the modular nature of the design could allow the size of the cube to be increased, or perhaps even take on a different shape entirely.
Generally the LED cubes we see are of the more wiry variety, so it’s particularly interesting when they take on solid forms like this one. Given the nearly universal popularity of blinking LED gadgets, we think this particular project is well positioned to make the leap from one-off hack to a commercial product.
Use a Qi charger.
Program/control over BLE.
Use an accelerometer (hit the cube) to turn it on.
Then “only” have leds on output sides.
Would a Qi charger get through the pcb+traces to the coil inside the cube?
Put the Qi charger on the inside and have a socket on the outside to connect it.
I love the idea of having it run off of a Qi charger.
Add a small lipo too, so you can pick it up and it’ll stay on.
I love the idea of it being wireless charged but I couldn’t work out if that would be possible through the leds and pcb layer. I’m using small pads on the bottom layer as a landing point for pogo pins to touch to This way I can charge and reprogramme by simply sitting it down on the “pedestal”. No cabling or disassembly required!
Add a loop on one of the corners, so it can hang from a string.
Have a small motor to spin the loop.
Add a microphone, so the lights can flash to the music.
Add a speaker so it can make its own music.
add Wi-Fi and camera too, (Google told me to write that).
Add an ESP32, because this is Hack A Day.
Have LEDs inside too!
IR transceiver.
555 timer(s)
What about the raspberry pi, this thing could be running a web server as well.
and a rocket and send to space …
While I know you’re being funny, I have consisdered a mic and Bluetooth as a way to sync to music. I think that’ll be in v2 so I can test with the cheaper v1. There’s space on the top and side pcbs to add these extra features .
A game, solid ON LEDs indicate the lines of a maze, a blinking LED indicates a “ball” to move through the maze. Admittedly, non-trivial, but there is a simple use for the interface.
Alternately use the LEDS to detect the presence of a finger over it, or not to indicate selection. I would quote a link for this but I am too lazy. :8-P
I have seen cubes as input devices, with the LEDs doubling for buttons, no problem.
7 sides can be sodered, 8th can be held on with connectors on the 4 sides.
I really like the maze idea. Currently I have a 9dof imu chip in the design. This will give me full orientation of the cube so I was thinking of a kind of snake game where you turn the cube to guide it. I would love to hear more about using the leds to detect input touches as this would be a really nice feature
http://www.thebox.myzen.co.uk/Workshop/LED_Sensing.html
https://www.sparkfun.com/news/2161
Using an LED as a sensor involves charging the LED like a capacitor, and measuring the amount of time it takes to discharge (which varies with the amount of incident light).
If instead you use only 6 sides, then you solve the problem of having to deal with the 7th and 8th, and you will still have a cube.
“which is of course eight times as bad when you’re building a cube”
and
“7 sides can be sodered, 8th can be held on with connectors on the 4 sides.”
Is it just me or are you fellas implying that a cube has 8 faces? Last time I checked a side definitely had 6 faces. Of course they have 8 corners but I don’t think that is what you meant?
Maybe in your dimension they only have six puny faces!
(Fixed the first think-o, but I couldn’t find the second reference with the connector count.)
Yep, botch the side count. Good catch.
The first quote is fine, because it’s talking about corners, of which cubes have eight.
Thanks Tom for the article! I appreciate the write up and any and all feedback. It’s nice to see others getting excited about some of my pipe dreams.
Sounds like the kind of project that might benefit from [Benchoff] PCB art ideas for when it’s off.
This article has given me some ideas, for yet another project to start and leave unfinished in a box. Maybe this time I will not order the parts straight away,
Wouldnt it be 24 times worse?
There’s 24 right angles in a cube, but I don’t think anyone would call those the corners unless you’re thinking in two dimensions.
But the proverbial corner that one might paint oneself into is 2d.
Here is another RGB LED version of such a cube: https://www.thingiverse.com/thing:1404797
I never understand why addessable LEDs (like ws2812) arent used for these cube projects. Seems to me you would have a ton less components and complexity, and youd have full RGB capability of each pixel.
Cost was my driving factor. 384 single colour is far cheaper than rgb. Bluetooth and wireless charging for v2, rgb and WiFi for v3!