Introduction: Arduino WorldClock (SwissGerman, Bärndütsch)

About: Maker, tinkerer, Arduino and Neopixel enthusiast

Created a WorldClock in Swiss German with air temperature and light sensor.

Based on and inspired by: Javelins-Word-Clock/

Source code:


  • 169 Neopixel
  • Arduino Uno (or similar)
  • RealTimeClock module DS3231
  • photocell
  • temperature sensor
  • Resistor
  • Capacitor
  • some wires
  • soldering kit

Step 1: LED Matrix

Create a 13 by 13 LED matrix.

Cut the strips and solder them back together. Make sure that the strips are all aligned in the same direction.

Use a zig zag layout


When you're done stick them a plate. Used aluminium to direct away any heat that may exist (wasn't an issues by now)

Step 2: Connect Parts Together

First try the connections with a breadboard as shown on the pictures. If all works well, solder it.

source code

Step 3: Front Plate Mask

In front of the LED matrix a plate with aligned holes is needed to prevent the LED from lighting more than just the intended letter.

Using Excel I created a 13 by 13 table with square cells. A plus "+" aligned in the center indicated the exact spot where to drill the hole.

This step is quite time consuming. I would recommend using a laser cutter if available (2 layers of 4mm plywood would be perfect).

Step 4: Black Acrylic Front Plate

I bought the acrylic plate online and used a Mars laser cutter from Thunderlaser, that was available in the maker lab to use.

First I created the svg file with inkscape. Print it and have a look if lettres are all aligned with led.

Then i used the laser cutters software LaserGrave to create the file for the cutter.

Do some trial cuts with cardboard of paper.

And most important. Do some trial cuts on the acrylic to determine the setting of the laser (eg. Power, speed). The laser needs to cut through entirely if not increase power or reduce speed. I always use 100% power and play around the the speed.

Step 5: Finish

Now the wordclock response to the brightness. The brighter the surrounding the brighter the LEDs.

So place the wordclock at the desired location and measure the brightness (via console) and adapt to the desired values.