I’d been wanting to build a split-flap display for a while. Back in 2020 I started gathering parts for Scott Bezek’s design - the laser-cut version with custom PCBs. I bought a bunch of 12V 28BYJ-48 stepper motors and hall-effect sensors and then… life happened, and the project sat in a box.

Fast forward to 2025, and I decided to actually finish this thing. But, the thing which kept me from finishing the project during the pandemic was still relevant: cutting out and labeling hundreds of individual flaps wasn’t a very appealing use of time. Thankfully, there’s more mechanical design out there these days. I modified a 3D-printed design from Makerworld, designed and built some custom electronics, and with a bit of debugging I have a fully working display! Here’s the finished product:

Over the past few years I’ve been having lots of fun playing with Home Assistant and home automation in general. One of the things which is underdocumented but kind of interesting is how to get air quality monitors connected to Home Assistant.

I currently use two different types of air quality monitors, both made by Qingping. There are, of course, alternatives, but the Qingping devices are reasonably priced when they’re on sale and they tend to look pretty nice.

I’ve been working on my online version of the shengji card game for a little while now. One of the more interesting aspects of the game is how a legal play is defined, and the corresponding algorithm to compute that.

Problem overview

Shengji is a trick-taking game, which means that in each round, every player plays the same number of cards. The first player in the trick sets the “format” of the trick, which subsequent players must attempt to follow. Only players whose plays match the format can win the trick (and then start the next trick).

I’ve been using Discord for gaming and hanging out with friends. However, sometimes I want to use my computer’s speakers (for friend hangouts), and sometimes I want to use headphones (for gaming).

On Windows there’s a handy system tray widget which lets you change the default playback device – and almost everything plays from the default playback device! However, Discord uses the default communications device when set to default… and you have to go into a menu to change that. Very annoying.

A year of Kubernetes

About a year ago I thought it would be a good idea to learn a bit more about Kubernetes. We use Kubernetes as part of our server orchestration at work, and while most of it is abstracted a way, it rarely hurts to know how the various foundational layers are actually like.

At the time, I tried to set up a three-node cluster (two computers at home, one in the cloud), connected together by Tailscale (i.e. via Wireguard). This… kind of worked, but it was super chatty, and when we moved to Seattle we no longer had an unmetered internet connection.

Or, why doesn’t docker stop work for my Docker image?

I’ve had a Docker image which is intended to be approximately the most basic HTTP-compatible responder for a while. But, I built this originally for playing with Kubernetes, which doesn’t really give you direct access to anything.

When actually using it with Docker, I discovered that it wouldn’t actually shut down correctly with Ctrl-C or docker stop, and Docker would eventually have to docker kill it.

This one’s pretty silly, but I decided I would try to use my little potato mini PC as a Samba host. And, it turns out, in the many years since I’ve configured Samba, so I forgot almost everything… and there’s some new stuff, too.

These instructions were only tested on my computer, which is currently running Ubuntu 22.04. May or may not work for you!

Setting up filesystem permissions correctly

Advent of Code is a pretty fun December activity – an advent calendar of programming puzzles with a story tying them all together. The puzzles are released at midnight ET, which is conveniently 9 PM PT.

I did Advent of Code for the first time last year (2021), and really enjoyed it. Since I became a manager I rarely get to write code for work (and try to minimize it, even so), and especially don’t get to write the kind of code that exercises the problem-solving part of my brain.

It’s been a long while since I’ve set up a new environment, and a long while since I’ve posted much of anything on here. Things have been pretty busy since we moved up here to Seattle, and I’ve been distracted by an endless supply of home improvement projects. Maybe some of those will make it up here!

As it happens, though, I finally got on the NVMe train and swapped out the main drive for my computer at home. And that means I have to set everything up again… including all the things I forgot I like to have on a computer. And it looks like some of my projects have suffered some bitrot, too…