Day 45, Homemade LED Clock

Published on 2025-06-02 by Mark VandeWettering

I have several digital clocks that I've made for my house. They all have a number of features:

  • They are build around a $3 microcontroller module called the ESP8266. These are amazingly powerful little microcontrollers which include a dual core processor and WiFi/Bluetooth.
  • They are running software that I wrote myself to contact Network Time Protocol servers (NTP) so that they never need to be set. When they wake up, they simply connect to my home network and ask for the time from a public server. After a power outage or during the daylight savings time changeover, they simply update their software. The implementation is simple, so is probably only accurate to half a second or so, but entirely adequate for the workshop.
  • They actually run a tiny webserver as well. On some versions, I can use them to display arbitrary messages, or run some kind of demo code. This one is the oldest of the examples, so is the simplest, and merely displays the time.

My clock on my pegboard above my workbench

This example is simply put inside a box I made out of OSB so I could attach it to my pegboard. Below it is one of those red siren/warning lights. I was going to set up some kind of warning light for it, but for right now it just cycles the red light. I was thinking of using it to monitor air quality in the garage and turn on when things got bad, but that got aborted half way through implementation and instead it just runs continuously.

I have to get this code up on github or something sometime soon.

Happy Monday all!