Is a bicycle like a motorcycle? Of course, the answer is it is and it isn’t. Saying something is “like” something else presupposes a lot of hidden assumptions. In the category “things with two wheels,” we have a winner. In the category “things that require gasoline,” not so much. We’ve noticed before that news stories about astronomy often talk about “sun-like stars” or “Earth-like planets.” But what does that really mean? [Paul Gilster] had the same questions, if you want to read his opinion about it.

[Paul] mentions that even textbooks can’t agree. He found one that said that Centauri A was “sun-like” while Centauri B was sometimes considered sun-like and other times not. So while Paul was looking at the examples of press releases and trying to make sense of it all, we thought we’d just ask you. What makes a star like our sun? What makes a planet like our planet?

Part of the problem is we don’t really know as much as we would like about other planets and their stars. We know more than we used to, of course. Still, it would be like wondering if the motorcycle was like that distant point of light. Maybe.

This is one of those things that seems deceptively simple until you start thinking about it. Is a planet Earth-like if it is full of water? What if it is totally covered in water? What if there’s no life at all? But life isn’t it, either. Methane-breathing silicon-based life probably doesn’t live on Earth-like planets.

Maybe Justice Potter Stewart was on to something when he said, “I know it when I see it!” Unfortunately, that’s not very scientific.

So what do you think? What’s a sun-like star? What’s an Earth-like planet? Discuss in the comments.

Don’t even get us started on super-earths, whatever they are. We are learning more about our neighbors every day, though.

Around these parts, we generally celebrate clever hacks that let you do more with less. So if somebody wrote in to tell us how they used multiplexing to drive the front panel of their latest gadget with fewer pins on the microcontroller than would normally be required, we’d be all over it. But what if that same hack ended up leading to a common failure in a piece of consumer hardware?

As [Jim] recently found out, that’s precisely what seems to be ailing the Meaco Arete dehumidifier. When his stopped working, some Internet searching uncovered the cause of the failure: if a segment in the cheap LED display dies and shorts out, the multiplexing scheme used to interface with the front panel essentially reads that as a stuck button and causes the microcontroller to lock up. He passed the info along to us as a cautionary tale of how over-optimization can come with a hidden cost down the line.

Judging by the thread from the Badcaps forum, the problem was identified last summer. But unless you had this particular dehumidifier and went searching for it, it’s not the kind of thing that you’d otherwise run into. The users start by going through the normal diagnostic steps, but come up short (no pun intended).

Eventually, user [CG2] resorts to buzzing out all the connections to the two digit seven-segment LED display on the front panel, and finds a dead short on one of the segments. After removing the display, the dehumidifier sprung back to life and everything worked as expected. It wasn’t hard to identify a suitable replacement display on AliExpress, and swapping it out brought the appliance back up to full functionality.

Now to be fair, a shorted out component is likely to cause havoc wherever it might be in the circuit, and as such perhaps it’s the lowest-bidder LED display with the unusually high failure rate that’s really to blame here. But it’s also more likely you’d interpret a dark display as a symptom of the problem rather than the cause, making this a particularly tricky failure to identify.

In any event, judging by how many people seem to be having the same problem, and the fact that there’s now an iFixit guide on how to replace the shorted display, it seems like this particular product was cost-optimized just a bit too far.

The tech press has been full of announcements over the last day or two regarding GPMI. It’s a new standard with the backing of a range of Chinese hardware companies, for a high-speed digital video interface to rival HDMI. The Chinese semiconductor company HiSilicon have a whitepaper on the subject (Chinese language, Google Translate link), promising a tremendously higher data rate than HDMI, power delivery well exceeding that of USB-C, and interestingly, bi-directional data transfer. Is HDMI dead? Probably not, but the next few years will bring us some interesting hardware as they respond to this upstart.

Reading through pages of marketing from all over the web on this topic, it appears to be an early part of the push for 8k video content. There’s a small part of us that wonders just how far we can push display resolution beyond that of our eyes without it becoming just a marketing gimmick, but it is true to say that there is demand for higher-bandwidth interfaces. Reports mention two plug styles: a GPMI-specific one and a USB-C one. We expect the latter to naturally dominate. In terms of adoption, though, and whether users might find themselves left behind with the wrong interface, we would expect that far from needing to buy new equipment, we’ll find that support comes gradually with fallback to existing standards such as DisplayPort over USB-C, such that we hardly notice the transition.

Nearly a decade ago we marked the passing of VGA. We don’t expect to be doing the same for HDMI any time soon in the light of GPMI.

Normally, videos over at The Signal Path channel on YouTube have a certain vibe, namely teardowns and deep dives into high-end test equipment for the microwave realm. And while we always love to see that kind of content, this hop into the world of cryogenics and liquid oxygen production shows that [Shahriar] has other interests, too.

Of course, to make liquid oxygen, one must first have oxygen. While it would be easy enough to get a tank of the stuff from a gas supplier, where’s the fun in that? So [Shahriar] started his quest with a cheap-ish off-the-shelf oxygen concentrator, one that uses the pressure-swing adsorption cycle we saw used to great effect with DIY O₂ concentrators in the early days of the pandemic. Although analysis of the machine’s output revealed it wasn’t quite as capable as advertised, it still put out enough reasonably pure oxygen for the job at hand.

The next step in making liquid oxygen is cooling it, and for that job [Shahriar] turned to the cryocooler from a superconducting RF filter, a toy we’re keen to see more about in the future. For now, he was able to harvest the Stirling-cycle cryocooler and rig it up in a test stand with ample forced-air cooling for the heat rejection end and a manifold to supply a constant flow of oxygen from the concentrator. Strategically placed diodes were used to monitor the temperature at the cold end, a technique we can’t recall seeing before. Once powered up, the cryocooler got down to the 77 Kelvin range quite quickly, and within an hour, [Shahriar] had at least a hundred milliliters of lovely pale blue fluid that passed all the usual tests.

While we’ve seen a few attempts to make liquid nitrogen before, this might be the first time we’ve seen anyone make liquid oxygen. Hats off to [Shahriar] for the effort.

Vibe coding is the buzzword of the moment. What is it? The practice of writing software by describing the problem to an AI large language model and using the code it generates. It’s not quite as simple as just letting the AI do your work for you because the developer is supposed to spend time honing and testing the result, and its proponents claim it gives a much more interactive and less tedious coding experience. Here at Hackaday, we are pleased to see the rest of the world catch up, because back in 2023, we were the first mainstream hardware hacking news website to embrace it, to deal with a breakfast-related emergency.

Jokes aside, though, the fad for vibe coding is something which should be taken seriously, because it’s seemingly being used in enough places that vibe coded software will inevitably affect our lives.  So here’s the Ask Hackaday: is this a clever and useful tool for making better software more quickly, or a dangerous tool for creating software nobody quite understands, containing bugs which could cause a disaster?

Our approach to writing software has always been one of incrementally building something from the ground up, which satisfies the need. Readers will know that feeling of being in touch with how a project works at all levels, with a nose for immediately diagnosing any problems that might occur. If an AI writes the code for us, the feeling is that we might lose that connection, and inevitably this will lead to less experienced coders quickly getting out of their depth. Is this pessimism, or the grizzled voice of experience? We’d love to know your views in the comments. Are our new AI overlords the new senior developers? Or are they the worst summer interns ever?

[BorisDigital] was mesmerised by a modern elevator. He decided to see how hard it would be to design his own elevator based on Raspberry Pis. He started out with a panel for the elevator and a call panel for the elevator lobby. Of course, he would really need three call panels since he is pretending to have a three-floor building.

It all looks very professional, and he has lots of bells and whistles, including an actual alarm. With the control system perfected, it was time to think about the hydraulics and mechanical parts to make a door and an actual lift.

It is still just a model, but he does have 10A AC switches for the pumps. Everything talks via MQTT over WiFi. There’s also a web-based control dashboard. We didn’t count how many Pi boards are in the whole system, but it is definitely more than three.

If you are wondering why this was built, we are too. But then again, we never really need an excuse to go off on some project, so we can’t throw stones.

Want to see a more practical build? Check it out. Perhaps he’ll start on an escalator next.

This week, Jonathan Bennett and Rob Campbell talk to Stéphane Graber about LXC, Linux Containers, and Incus! Why did Incus fork from LXD, why are Fortune 500 companies embracing it, and why might it make sense for your home lab setup? Watch to find out!

• https://stgraber.org
• Incus: https://linuxcontainers.org/incus
• Online demo: https://linuxcontainers.org/incus/try-it/
• https://github.com/lxc/incus
• Incus Deploy: https://github.com/lxc/incus-deploy
• Incus OS: https://github.com/lxc/incus-os
• Terraform Provider: https://github.com/lxc/terraform-provider-incus
• Migration Manager: https://github.com/futurfusion/migration-manager

Did you know you can watch the live recording of the show right on our YouTube Channel? Have someone you’d like us to interview? Let us know, or contact the guest and have them contact us! Take a look at the schedule here.

Direct Download in DRM-free MP3.

If you’d rather read along, here’s the transcript for this week’s episode.

Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)

Licensed under Creative Commons: By Attribution 4.0 License