Turning the UnicornHAT round 'pixels' into square ones


Hey all, I’m brand new to this whole ‘maker’ scene (coming from a coding background), so apologies if I’m saying anything dumb.

I have a UnicornHAT, which I’m really enjoying playing with, but for the project I want to use it for, the round ‘pixels’ that it uses aren’t going to work - I’d like them to be square. I’m also keen on them being diffused, so I’m able to look at them without getting blinded.

So, what I was wondering is if it would be possible to create some type of clear plastic, uumm, converter (???) for each pixel? That is, a tiny bit of clear/frosted plastic, which is round on the bottom, but square on the top, which could be placed on the individual LEDs, to transform their shape into a square.

If something like this is possible, how would I go about making it? Or, indeed, having it made?

Thank you.


I came across this for a larger NeoPixel board,and have designed my own for the Unicorn Hat that I intend to get 3D printed at some point.


Ah, that looks perfect, and I’m guessing far simpler than what I had in mind. Would you be willing to share the design for the UnicornHAT compatible one? Cheers.


Yeah sure, will send it on when I’m back at my main PC. I need to double check my dimensions tho. :) It was my first design for 3D printing, and it could probably do with some tweaking. Hopefully going to get one printed pretty soon :)


I know someone that has a 3D printer, so if I asked him nicely (and gave him some money to cover the cost) he might be willing to print them up for us. I know he’s got an interest in the RGB LEDs, so this might be well within his wheelhouse… I’ll send him a link to this thread.


I did this a while back with some laser cut acrylic and some sticky labels for diffusing. It’s a royal pain to cut, though, lots of tiny holes!

And in motion: https://vine.co/v/eU62UBJiQJL

You could probably do it with a number of other things, like balsa wood, or stiff black card and a lot of patience.


Just for some context, I love the idea of using the UnicornHAT to display some small 8x8 pixel characters, such as this:


So to get with the whole retro vibe, I feel squares would work so much better.


I’m the someone with a 3D printer :)

My take on this is that you need 2 things printing. A separator to stop bleed from 1 LED to the other - similar to the one linked, and then I would print a transparent cover atop this that located into the square holes of the separator and within each hole had a slight pyramid shape pointing downwards to the LED.

This would disperse the light more in the middle and allow more light through around the edges and would help to turn the round light square.

I’ve got a 8x5 Neopixel shield for Arduino that I could try this on.


Incidentally, I mentioned to LimeBlast that I want to try my own PCB fabrication and fancied doing a more dense NeoPixel-like panel.

The LEDs are dirt cheap on Aliexpress (10p ea) and the only other thing required is a 74AHCT125 power level converter.

Not quite sure how I’d get on soldering them though - might have to try hot air - but at the moment I’ve no spare funds for such endeavours atm.


@defsdoor @LimeBlast I forgot to come back and update this thread with my results:



That looks fantastic, just what I want.


Here’s my Thingiverse page.


I need to get myself a 3D printer. Thank you :)