Full Width [alt+shift+f] Shortcuts [alt+shift+k]
Sign Up [alt+shift+s] Log In [alt+shift+l]
1

It's not that hard to stop a Trane

from Jeff Geerling [alt+shift+b] in technology

It's not that hard to stop a Trane Six years ago, I replaced the old HVAC system that came with our house, a central forced air system installed in 19951. The new system is a Trane XR AC paired with an S9V2 96% efficiency forced-air gas furnace. And it ran great! Better efficiency, quieter, multiple fan speeds so I can circulate air and prevent stale air in some parts of the house... what's not to love? Well, apparently the engineering: Jeff Geerling November 4, 2025
4th Nov 2025

Stay updated

Get a weekly newsletter with the top 5 articles worth reading every week.

More from Jeff Geerling

Radxa's Q8B has 2x the performance and expansion of the Pi 5

There was a time I'd look at a board like the Radxa Dragon Q8B (at left, above) and be like, "there's no way I'd spend $209 on an SBC with 8 gigs of RAM". But we're in 2026, and seeing the 8 gig Raspberry Pi 5 going for almost the same amount, I figured I'd give it a shot. On paper, the Q8B beats the Pi 5 in pretty much every way. A lot of that is thanks to this Snapdragon 8cx Gen 3 chip, which is the same chip I tested on Microsoft's Windows Dev Kit 2023.

2 weeks ago • 1 votes
Rebuilding a 1995 GPS Time Server so I don't get Telstra'd

In June I purchased this TrueTime XL-AK time server, so I could learn more of the history of GPS-based time. I received it on June 22, and just 16 days later a similar GPS time server took down Australia's cell service for 12 hours! I made a short video about it but put off digging into the TrueTime... until now. Over the past couple weeks, I've 'restomodded' this device with a Raspberry Pi, to build a stratum 1 NTP Time server, which I'd like to eventually add to the NTP Pool. I found a way to drop in a Pi 5 and GNSS HAT, display the time and GPS status on the built-in 16x2 LCD, show the status on the bicolor LED, and make this box useful again.

4th Sep 2026 • 1 votes
Proxmox officially supports Arm, with some caveats

Proxmox today announced their Proxmox Virtual Environment is now available for 64-bit ARM. I tested it on my Ampere Altra Dev Platform—the same machine on which I've booted Windows on Arm the first time, messed with multiple GPUs, and most recently tested Houdini's native arm64 support. Install was easy, as the Ampere Altra uses UEFI / ACPI for its hardware, meaning Proxmox didn't have to tailor it's ISO to specific platforms, like you have to do with Raspberry Pis and most SBCs using a Device Tree setup.

5th Aug 2026 • 1 votes
I tested every IP KVM in my Homelab

Since the PiKVM came out in 2017, there's been an explosion of IP KVMs. I've tested almost every one. But what are they good for? You can use Remote Desktop, Screen Sharing, or VNC to remote control a computer from anywhere on a LAN. And if you don't have a private VPN, you could use RealVNC, Raspberry Pi Connect, or wire up Tailscale or Pangolin for fully remote access. Those solutions are great, and so is SSH if you don't need a full desktop.

5th Jun 2026 • 1 votes
SBC Clusters are a terrible value, but they're fun anyway

Pictured above is the new DeskPi Super4C installed in an 8U mini rack. The Super4C is a 4-node Raspberry Pi CM5 cluster board that solves two pain points I had with the older Super6C. I was testing this board around the same time I helped kick off the SBCC 2026, the Single Board Cluster Competition for students. A dozen or so university teams squared off to run the best mini HPC cluster with a budget of $6,000, and a couple days to benchmark six HPC workloads.

1st May 2026 • 1 votes

More in technology

Clothes Rail

[Misc] Tubular

17 hours ago • 1 votes
List of Vim forks

Here are the Vim forks I know about: Neovim: “a Vim-based text editor engineered for extensibility and usability, to encourage new applications and contributions.” Vim Classic: “a stable, long-term support fork of the ubiquitous text editor, maintained without the assistance of generative AI tools.” EVi: “a hard-fork of Vim v9.1.0 (Jan 2024) before AI was used in the project.” MacVim: “a macOS version of the Vim text editor, providing a graphical user interface for Vim, while tightly integrating with macOS and providing features specific to the platform.” This list doesn’t include Vim-inspired editors like Kakoune, Vim-style plugins for other editors like IdeaVim, or Vim “distributions” like LazyVim. Contact me if you know of other forks!

22 hours ago • 1 votes
iOS 27 has some weird Dynamic Island behavior

Thought I’d make a quick blog post about some weird behavior I’m seeing on iOS 27 and Dynamic Island live activities, that I initially thought was restricted to the Duo, but turns out affects everything. Yay. Maybe this post can save some others some time, and hopefully Apple can fix it. Long story short, ever since iOS 16.1 introduced “Live Activities”, where we can display handy little widgets in the Dynamic Island, there’s been a bunch of different configurations for showing things up there: something on the left, the right, when expanded, when two apps are showing things and yours gets a bit smaller, and on the lock screen. One interesting one is if you only need to show a small indicator in the Dynamic Island (screen recording indicator, electric vehicle charging status, etc.) you can do so, which just shows on the left on older iPhones, and on the Duo a single one below the camera cutout. Apple describes how to do this in their developer documentation (emphasis added): If you can’t find a solution to display views for leading and trailing compact presentations with limited width, provide a compact leading presentation that best represents your Live Activity, such as the view you use for the minimal presentation, and an empty view for the trailing compact presentation. The system hides the empty trailing view automatically. Unfortunately, in iOS 27 (and 27.1, and 27.2), this only half works, due to a new addition in iOS 27: isDynamicIslandLimitedInWidth. It’s a variable that basically tells you if the Dynamic Island is even narrower than normal, presumably because they knew the Duo was coming with its vertical Dynamic Island, but also because as of iOS 27, Live Activities now show in the Dynamic Island when the device is in landscape too. So it’s handy to know if you have a bit less space than usual. In this new narrow view however, it seems like they didn’t test all the configurations thoroughly, as if you provide EmptyView for that trailing compact presentation, it’s not empty at all, and in fact enforces a quite large minimum size so the Dynamic Island looks hilariously tall. In other words: The system hides the empty trailing view automatically Left: what it should look like. Right: reality You can imagine this is especially rough on the Duo, where navigation buttons, toolbar buttons, tab bar buttons, etc. are all competing for precious space on the right. But that’s only half true. It displays perfectly fine (hiding it) when isDynamicIslandLimitedInWidth is false (AKA how it always used to be), but in the new cases where it can be true, like the Duo and iPhones in landscape, that’s when it breaks. So tl;dr: In iOS 27, Dynamic Island Live Activities are improperly sized if you use the listed EmptyView configuration and isDynamicIslandLimitedInWidth is true. This makes it especially bad on the Duo, womp womp. Complications Now, you might be saying “That’s weird, I haven’t seen that behavior! This is nothing but hogwash!”. But it is not hogwash, just a little complicated. There’s basically three categories of apps. Apple apps Maps, for instance, displays this single, small Dynamic Island live activity perfectly well and sized, and has been beautifully compiled with the iOS 27.2 SDK. By all accounts it should show this bug, too! Apple apps don’t have to use the same APIs as us normies, so funnily enough through really cool tools like REA we can disassemble the iOS Simulator and see that it’s in fact true, the Apple Maps live activity just completely bypasses WidgetKit and instead just renders plain UIKit through MapsBannerViewController which shows the cute little cyan widget through a ManeuverAccessoryView and then for the hidden trailing view simply returns a DistanceAccessoryView with CGSizeZero, which iOS actually respects, unlike our paltry SwiftUI EmptyView. Third-party apps NOT updated to iOS 27 If your app hasn’t been compiled with any of the iOS 27 SDKs, it only knows about iOS 26, and thus doesn’t know about (or have to worry about) the new, troublesome isDynamicIslandLimitedInWidth property, so it just… displays perfectly well. Here’s the Rivian app, which hasn’t been updated for iOS 27 yet, which shows the Live Activity displaying perfectly sized on the Duo (indicating vehicle charging): (Technical disassembly detail for the nerds: iOS shows the app’s minimal config, a smaller config normally used when multiple apps are in the Dynamic Island together, rather than the normal compact config, so it bypasses this issue entirely.) Developers who updated their apps for iOS 27 Surprise! That picture from before? On the left is just me compiling with the old 26 SDK that works! Unfortunately if you are a good developer who updated their app for iOS 27 and all the new features, you kind of get punished through this bug, because your live activity displays the improperly sized way described above, and you can’t just use raw UIKit like Apple. So you’re kinda stuck where I am: do I ship a weirdly sized Dynamic Island experience for everyone? Do I shove something extraneous in the compactTrailing spot just so it doesn’t look as empty? Do I not update the app at all until Apple fixes this bug? Widgets are techincally a separate extension from your main app, so you could compile them with a different SDK (26) than your main app (27) which fixes this bug, but I’m not sure Apple approves of that. Apple On the bright side hopefully it’s an easy enough fix, treating EmptyView like you used to on iOS 26 and per the documentation (the part that is weirdly right beside the mention of the new API that introduces this craziness in the first place). Radar/feedback assistant ID: FB25301955 Easy reproduction code if you’re curious: import ActivityKit import SwiftUI import WidgetKit struct CircleAttributes: ActivityAttributes { struct ContentState: Codable, Hashable {} } struct BlueCircle: View { var body: some View { Circle() .fill(.blue) .frame(width: 20, height: 20) } } @main struct CircleLiveActivity: Widget { var body: some WidgetConfiguration { ActivityConfiguration(for: CircleAttributes.self) { _ in BlueCircle() } dynamicIsland: { _ in DynamicIsland { DynamicIslandExpandedRegion(.center) { BlueCircle() } } compactLeading: { BlueCircle() } compactTrailing: { EmptyView() // pls respect me } minimal: { BlueCircle() } } } }

yesterday • 1 votes
Going Somewhere

Vicky, driving me home from O'Hare, got sixteen dollars for the best conversation I had in months. The last line is hers.

4 days ago • 1 votes
An AI usage statement for bryanbraun.com

I’ve had “AI usage statements” in the back of my mind ever since I read Ethan Marcott’s blog post sharing a round-up of his favorite ones. I didn’t consider writing one for this site, since it had the smell of status-signaling. Like a quasi-political declaration of allegiance to some sort of in-group (be it pro-AI, anti-AI, etc). I couldn’t be less interested in that.1 But then something happened that caught me completely off-guard. I was reading a post on my friend’s personal blog. This was a guy that I knew personally and looked up to. I’ve been reading everything he had been writing for years. About two-thirds of the way through a long (and fairly insightful) blog post, I had a sudden realization that the post had been written by AI. I’m not the best at detecting this kind of thing, but once I saw it, I couldn’t unsee it. It was unmistakable. And the thing is, I didn’t feel indifferent or even disappointed, as I might have predicted. I felt betrayed. For somebody who considers themselves open-minded—even optimistic—towards the development of AI, I didn’t know where this feeling was coming from. I have theories… maybe it has something to do with the social contract between the writer and the reader. Whatever it is, I didn’t want anyone who was reading my blog (hi mom 👋) to feel the same thing. So for the sake of transparency, here is my AI usage statement: The content of this website is written by me. I do not use AI to generate the text you are reading because writing from scratch helps me process my thoughts (which is one of the main reasons I blog in the first place). I don’t currently use AI-powered writing tools (grammar-check, spell-check, dictation tools, etc), but I may experiment with them as long as they don’t undermine the thinking process. The code for this website was originally hand-written, but I have since used AI to make several useful updates. I expect to continue using AI to write code for this website and other personal coding projects. When I create a public project exclusively with AI, I mention that fact in the project README.2 I am experimenting and my AI usage may change. When it does, I’ll update the policy here on my /about page, which is where it will live long-term. To explain why, see Paul Graham's Keep your Identity Small. ↩ For an example, see s-tier ↩ Thanks for reading this post via RSS! Let me know your thoughts by leaving a comment on the original post or sending me an email.

5 days ago • 1 votes
📚 BoredReading

You seem to be enjoying this.

Join free to unlock everything.

Create free account

Already have an account? Sign in