Matrix Pixel Clock 16×16

Matrix Pixel Clock 16×16 - A story of a little pixel, retold every minute.

Matrix Pixel Clock 16×16 plays with time and displays it through physically animated digit changes. Configuration and updates run entirely on the ESP32.

Notes

• 15. July 2026: Software version V1.1.0 is out and adds 2 new functions:

  • Switch between online or offline mode if you want to run the clock in environment without WiFi available. The device will open an internal WiFi access point like known from my WordClock models and you can set the actual time and still set colors there in the still available web configuration portal too.

  • The 2nd new functionality adds custom profiles for your own color choices which can be saved to the configuration and even be updated or deleted too.

  • Simply update the device from V1.0.0 to V1.1.0 with the internal update function. New created Matrix Pixel Clock devices automatically will be setup with the newest software anyway. =)

Video

• The video shows the WPS WiFi setup and the general function.

• During the time is displayed the color palettes are changed but the camera cannot really make a good job here. This looks way better in person than on video. Filming such devices or taking pictures is really hard. So keep this in mind please.

Web interface

• Welcome page with live preview of the display explaining the current story of the little pixel.

• The web interface is available in German and Englisch language as well in the here shown dark mode and a light mode if you prefer this.

• LED display settings with the below shown options and 20 preconfigured color palettes and a custom setting if you wand totally different color settings:

• Color palette 1/2:

• Color palette 2/2:

• Settings page with the following settings and informations:

  • WiFi settings informations including the WiFi signal strength to see the connection quality 

  • The „Refresh WiFi signal“ button tries to connect to a stronger access point in your WiFi mesh of access point which works really well to my testing

  • The button "Delete WiFi credentials“ just removes the WiFi settings and keeps all other config

  • Time server and time zone settings can be set too

  • You can perform direct software update from the internal web interface with 2 clicks. Newer software is automatically downloaded from my server for you convenience. This is used for my other projects now for years

  • The buttons to restart the device and to set it fully to default should be self-explanatory 

Here is a view of the WiFi signal strength table you can expand to see the rating:

On the profile page you can see some more information and have the links to my other projects as well as the ESP32 flash script you will need to flash the ESP32 again if needed:

Setup the code 

• Code download:

  • The script to upload the code can be downloaded from my GitHub repository

  • Use option “9” to flash this project to your ESP32

  • The script can be used with MS Windows 10/11, Linux or macOS too 

  • Follow this video to get used to the usage: 

Setting up the WiFi connection to update the time and config

• Setting up the WiFi connection to your local network is as easy as possible and you have 2 options:

  • WPS: Just press the WPS connect button 1x on your router or access point within 2 minutes after you plugged in the device. That is it. The clock will restart and is connected. The LED display will give you instructions to this.

  • WiFi Captive Portal:  After the first 2 minutes the WPS options turns off and the internal temporary web portal of the ESP32 turns on. Just follow along the shown actions also show in the above linked video for a WordClock but the process is the same. WPS should be the preferred option because you can set it up in 1 click without any password entered etc.

• After the device is connected by either way the LED display will show WIFI first in blue while trying to connect to the set WiFi and then WIFI in green color if successful. 

• After the connect is done the from your router received IP-address is shown on the display which you can use to enter the web configuration. If you missed this output simply restart the clock by resetting its power.

Update the code of a running device:

• Updates can be done “Over The Air” / “OTA” with the internal web portal.

• You will find a section to get the update without the need of a computer with 2 clicks.

Printing instructions:

• No supports needed for all parts.

• Using a brim was not needed in my tests, because I cleaned my textured sheet with dishwashing liquid carefully with a new sponge and then with isopropanol alcohol again on the printer to make the parts stick really good. If you face problems with adhesion feel free to add a 5mm brim to the front and lid part.

• 0.2 speed profile used. 

• Textured sheet used:

  • If you use a textured sheet too, let it cool down completely after the print and wait for the part gets loose by itself.

  • In my case it takes 20-30 minutes after the print has ended and the part just lays loose on the print bed.

  • Do not touch the print bed and clean it with Isopropanol alcohol before printing.

• The option “Avoid crossing perimeters” was set active for the front parts in Prusa Slicer.

• The 4 screws should be printed with 30-50% infill just in case you need to screw them in a little harder. I could use 15% infill good as well, because you screw them in 1x only.

• IMPORTANT: 

  • One (1) color change in the front part from white to black again are required at about 1.4mm height to create the diffuser layer.

  • Color changes are done in this order:

    • 1st color = white 

    • 2nd color = black

• To read how such a color change is done, you will find a really good article here.

• If you use the .3MF files the color change is preconfigured for 0.2mm layer height.

Parts needed:

• 1x 16x16 LED matrix (Use this one. The case is made to fit to it only!)

• 1x NodeMCU ESP32 USB-C (Use this one. The case is made to fit to it only!)

• 1x USB power supply 5V / 3A or e.g. the USB-A port from this one (No direct USB-C!)

• 1x USB-A to USB-C cable (5V, 3A) (No direct USB-C!) 

• 1x USB-C port (5V, 3A)

• 3x Wago 221-413 - 3 wire clamps

• 3x Jumper Wire 40x 20cm, Male-Female

• 3x M3x16 screws

• 4x M3x8 screws

Tools needed:

• 1x FDM 3D printer and PLA filament in black and white 

• 1x Wire stripper

• 1x M3 allen key

• 1x side cutters (to cut the cable ties and cables cleaner)

• 4x cable ties

• 1x soldering iron set (if you want to solder)

• 1x 3rd hand (if you want to solder)

Wiring: 

• Connecting the parts for this device is as easy as possible.

• You may need to solder or connect solder free 3 connections only to the ESP32.

• The small holders in the lid can be used for a small cable ties to secure the cables.

• Have a look into the pictures how to arrange the LED matrix in the front part to ensure that the direction of the LEDs is correct.

• In case you want to solder, the only change compared to the solder free variant would be to solder the 3 wires to the ESP instead of using the named plugged cables. Details will not be described here due the connections are the same as for the solder free variant. The Wago clamps would be used in this case too, because they are really handy to use…

• Please check the table which pins are connected for the project as well as the pictures:

USB-C port:

ESP32:

LED matrix:

Wire color:

5V

VIN

5V

Red

GND

GND

GND

Black or White

D32

DIN

Green

Here is a step by step guide how to connect all the cables:

• The pictures were taken from a WordClock model but you should be able to follow along because the general process is exactly the same here.

• Basically you can use the electronics and back of an existing WordClock 2024 or 2025 to try the function without any changes needed...

• With the help of the following pictures you will see how to wire the device, easy as 1,2,3:

• Here you see all the required parts. 

• Cut off the middle and lower cable pairs from the matrix to avoid electric short circuits. The cables at „DIN“ have to remain. The result is shown here.

• Add the LED matrix in the orientation as shown. 

• Next strip the 2 USB-C port wires 11mm and push it into its place in the lid. It will click in place with a bit of the force. ;-)

• You will find a 11mm long mark in the case to help you finding the right strip length. See the upper edge in the picture above with the "11".

• Open the 3 Wago clamps and put them into their holders in the lid as shown.

• Remember the 1,2,3 under the clamps as:

  • 1 = red = 5V

  • 2 = black or white = GND

  • 3 = green = DIN

• Add the 2 stripped USB-C port wires to the clamps 1 and 2 as shown and close the clamps on the used slots.

• Add the 3 Female-Male cables like shown to the clamps and close their slots as:

  • 1 = red = 5V

  • 2 = black = GND

  • 3 = green = DIN

• The male pin part of the cable is pushed into the clamps. 

• Add the “female” part of the cables to the ESP32 like shown:

  • VIN = red = 5V

  • GND = black = GND

  • D32 = green = DIN

• Carefully push the ESP32 and the 3 cables with their black posts in to the tight holder part of the lid as shown.

• Route the 3 cables out of the small slots. 

• Secure the ESP32 in place with the 4 M3x8 screws.

• As last part add the with the LED matrix delivered connector to the circuit.

• Do not forget to strip its wires 11mm too. 

• Add the 3 last wires as shown and close the Wago clamps:

  • 1 = red = 5V

  • 2 = white = GND

  • 3 = green = DIN

• Add the USB-C part of the USB-A-to-USB-C cable through its hole in the lid and plug it into the USB-C port like shown. 

• If you followed all instructions carefully, checked them again and check that all clamps are closed. 

• Please add some small cable ties to secure the cables in place. Especially the power cable should be secured in place.

• If you haven't uploaded the code to the board yet, you should perform this action now!

• As last action you have to do is to connect the LED matrix to its connector in the lid.

• Slide the lid carefully together with the front part as shown.

• The lid pushes the matrix down and holds it in place. No tape or glue etc. needed.

• Use the 3 M3x16 screws to fix the lid in place to the front.

• Plug the clock to its 5V/3A power supply. 

• Check the function and you finished the setup.

• Enjoy! =)

Happy printing =)