I Wanted a Clock That Never Needed Setting. Things Escalated.

Freeman writes:

https://arstechnica.com/gadgets/2026/07/i-wanted-a-clock-that-never-needed-setting-things-escalated/

I wanted a clock that, annoyingly, didn't seem to exist.
[...]
My perfect clock would be self-setting. It would offer auto-DST adjustment (or not, depending on how this bill fares!). It would manage drift and always show the exact sub-second time. It would show that time on a red seven-segment display-not blue, not green, not yellow, and absolutely not white.
[...]
Battery-backed self-setting "atomic" clocks that get their updates via the cosmic ether have been a thing for years and get me most of the way there, but damned if I could find one with a red seven-segment display that I liked (maybe someone else's search kung-fu is better than mine?).
[...]
I thought to myself, "Wait a second. I've got a 3D printer. I'm, like, smart and stuff. Why not buy a seven-segment display and make my own clock?"

And so, standing on the shoulders of giants stacked up so high that I could practically touch the Moon, I did.
[...]
here's the finished repo. It contains my bill of materials with prices and purchase locations, the software, and the 3D printer files
[...]
a Pi gave me the security blanket of a Debian-based operating system, complete with Wi-Fi and NTP for the "the clock sets and updates itself" requirement, along with the usual Linux remote management routine I already know.

Picking a seven-segment display was easy: Adafruit makes awesome clock-face style LED displays with 1.2-inch high numerals, and it sells a kit that bundles the display I want with a "backpack" board containing the HT16K33 controller needed to drive the LEDs. I ordered three and ended up using all of them for testing, assembly, and figuring out how to solder.
[...]
I grabbed a baby's-first-soldering-iron kit from Amazon and a roll of 60/40 solder. (I also had to buy a desktop magnifying lens, because as I found out when I got in there, these old eyes can't focus up close like they once could.)
[...]
I distilled my software requirements down to a list:

• The clock host should be LAN-only and not accessible from the Internet
• The clock host should get its updates from a LAN-only apt mirror
• The clock host should get its NTP sync from a LAN-only NTP server
• The clock service should be a systemd service running unprivileged under a dedicated service account context
• The clock service should use the system time, so the host OS handles NTP and keeps us in sync with whatever DST is or isn't doing
• The clock service should be able to turn the display on and off on a schedule so it's off for most of the day when I'm not in the bedroom
• The clock service should also be able to brighten/dim its display on a schedule
• The clock service should have some way of being controlled via the CLI for terminal connections, too
• The display should be controllable via HomeKit, because I live in iOS-land
• The clock service and its dependencies should be installable via a single script
• Once installed, everything should be deployable so I can push updates if needed rather than having to log in and reinstall

Read more of this story at SoylentNews.