7-segment displays are useful in many electronic projects, but the 4-digit modules commonly used in Arduino or Raspberry Pi tutorials (e.g. those using TM1637 or MAX7219 chips) are just... a bit small...
So, I decided to create my own display using a WS2812B programmable LED strip. It uses a modular design, which means it can be scaled to accommodate pretty much any number of digits, of any size - you just need to use a longer length of LED strip!
If you have access to a 3D printer, you can print an enclosure for each digit and diffusers for the individual segments (the version I demonstrate in the video are 8" high), but you can also create these on a CNC, or just layout LED strips by hand and use baking paper or thin white plastic sheet as a diffuser. And, because the LEDs have separate RGB components, you can even create animated colour-changing effects on the digits !

STLs remixed from a design by sockser (https://www.thingiverse.com/thing:523..., based on an original design by parallyze: (https://www.thingiverse.com/thing:500..., licenced under a CC-BY-SA licence (https://creativecommons.org/licenses/...) and can be downloaded from https://drive.google.com/drive/folder...

To demonstrate the display, I've created an Arduino sketch that implements both a count-up stopwatch and also a countdown timer, displaying the time in MM:SS or SSSS format. This could be used in any kind of exercise challenge, escape room, or even as a timer to monitor how much screen-time allowance your kids have still got left :)

Timings---00:00:00 - 00:02:13 Introduction00:02:14 - 00:05:22 Using WS2812B ("Neopixel") LED strips00:05:23 - 00:08:28 3D Printed modular 7 segment case00:08:29 - 00:10:41 Arduino stopwatch timer and countdown
00:10:42 - 00:11:31 Fritzing wiring diagram00:11:32 - 00:39:55 Arduino code
00:39:56 - 00:41:07 Wrapup and conclusionIf you enjoyed this video or found it helpful, please like and subscribe to this channel! And, if you'd like to download the code for the Arduino IDE, the wiring diagram, or other resources used in this and all the other escape room projects shown on this channel (and support me to continue making more tutorials in the future!), please check out my Patreon at   / playfultech