Nov 18, 2025

Making a DIY circular LED matrix

Introduction

A few months ago we - the puppet team (TM) - joined the fablab neukölln art makerthon. We had 48 hours to make something that should fit in a specified round frame and that we could showcase afterwards.

The frame we were given

flo-bit is a sucker for anything made with controllable RGB LEDs and he can be very convincing when he’s passionate (and what could possibly worth more passion than individually controllable RGB LEDs?).

So we basically just put a bunch of LEDs into that frame and made a round display.

Here are a few of the cool effects it can show, curtesy of WLED.

This blog post is both the story of how we made it, as well as a how-to guide if you wanna make your own.

We did initially plan to have this work together with a camera and be a “pixel art” mirror and while we did get this kinda working for the demo, for the how-to we’ll concentrate on how to make the LED frame with just the effects above (so without the mirror functionality), as the mirror part is honestly very hacky and doesn’t even look that good imo.

Requirements

If you plan to try your hand at making one, you need two things apart from the materials:

A solder iron (some experience with soldering might be useful, but this is also a good learning project, we don’t really know how to solder either, we just do it and sometimes it works 😝)
A laser cutter that has a cutting area of at least 40cm x 24cm, if you don’t have one, check your nearest makerspace

Bill of Materials

For the materials you need: (without the mirror functionality, for that you’d also need a raspberry 3b or above with wifi and a camera).

(links are to the german amazon, those are not referrer links, just where we bought stuff)

7 meters of WS2812b with 60 leds per meter in total 420 (noice) LEDs (amazon)
1 esp32 (we used a D1 mini with usb c) (amazon)
some small wires
usb cable (depending on the esp32 you use either usb-c or micro-usb) and plug (or a powerbank if you want to make it mobile)
3 plates of 40cm x 24cm plywood (we used 3mm thickness but it doesn’t really matter)
4 cardboards (40cm x 24cm, preferably 3mm thickness)
a white cloth thats at least 46cm x 46cm (we used an old bed cover)
glue

Total cost

35 € - 40 €

The main cost are the LED strips, we bought them from amazon for 15 € for 5 meters (so 7 meters are ~21 €). There are cheaper options available on something like aliexpress though.

An esp32 costs about 7 € (again less on aliexpress) and the wood we used was about 8 € for the 3 plates.

Everything else we had at home, but should be pretty cheap anyway (less than 5 €, if you don’t add a powerbank).

Step 1: Making the frame

First we created the backframe, by lasercutting 2 of the plywood plates. Here are the files both for LightBurn and as SVGs:

Base

Round base as lightburn and svg version

Download

Note that there are 2 layers, the first should be cut, the second is just for marking the LED strip positions (so use low power for that one).

The rings for the front were given to us already laser cut, but here are the files for anyone following along at home (from this fablab github repo). Use the last plywood plate to cut out the ring segments.

Frame

Frame as lightburn and svg version

Download

Use some wood glue or just duct tape to glue the parts together and you should have two rings and one big circle with markings on one side for the LEDs (you might be able to guess wether we used wood glue or duct tape…)

The backside of the base plate.

Step 2: Adding the walls

The walls are also lasercut but out of cardboard (would have taken way to long to cut them out of wood and we were in a hurry, you can cut them out of plywood too, but in the end they wont be visible anyway). We just used random packaging cardboard we had laying around.

Walls

Walls as lightburn and svg version

Download

Afterwards you can lay them on your base board (good luck figuring out which go where, we don’t have a good tip here, we struggled with that too 🙃) and start putting them together, we tried that without glue first, but after everything fell apart twice we went for some glue.

The cardboard grid.

Step 3: Cutting the LED strips

Now for the first of three steps where you have to pay attention not to fuck it up: Cutting the LED strips into segments in with the correct amount of LEDs for each segment.

When cutting also make sure LED strips are cut exactly in the middle of a connection (so you have enough place to solder on both parts).

In total you need:

2x 8 LEDs segments
2x 12 LEDs segments
2x 14 LEDs segments
2x 16 LEDs segments
2x 18 LEDs segments
4x 20 LEDs segments
6x 22 LEDs segments
3x 24 LEDs segments

You can also directly lay them on the board (don’t glue them yet though) to make sure you have the correct count, they should fit perfectly in the little markings on the plate (lengthwise, they are less wide than the markings)

Step 4: Glueing the LED strips

the LED strips have to be laid out in a serpentine arrangement with the correct count.

there are little arrows on the LED strips that show you the direction there are going, those should alternate go left to right then right to left.

Step 5: Soldering the LED strips together

Again pay lots of attention here, you can accidentially fry your LED strips if you make a mistake here (we’ve of course never fried any LED strip cough, cough, thankfully the LED strips are usually sold as 5 meter strips so you have some leftover)

On each LED strip connection, solder together the 5V, ground and data connection like so:

In the end you should have something like this:

Professionally soldered I would say

Step 6: Flashing the ESP

Take your esp32 and connect it to your computer (be sure to use a cable that has a data connection) and open this website:

install.wled.me

Install WLED

Click on install, select your usb port, confirm and wait a few minutes until it’s installed.

Once it’s done you’ll be asked to enter your Wifi credentials, do that and then click “Open WLED”. You should see a screen like this:

Main WLED screen.

Step 7: Setup the grid

Click “Config” in the top bar to open the settings page, there click on “2D configuration”:

WLED settings screen.

Check serpentine and enter the dimensions as 24 by 23 LEDs.

WLED matrix screen.

Scroll all the way down and upload this gaps.json file:

gaps.json

gap file for WLED 2D settings

Download

Select gaps.json file and click upload

Optionally go back to the main page and select a different effect (e.g. rainbow).

Step 8: Soldering the connection onto the ESP

Last soldering part: solder VCC, ground and GPIO4 to the beginning of the first LED strip (GPIO4 goes to data, VCC to 5V and ground to ground, optionally you can use the 3 pin connectors that are usually part of the LED strips).