Hackaday Europe 2026: Playstation 4 To Psychometer

September 1, 2026 by No comments

There are many ways to detect stress in an individual. You can use self-reporting checklists, you could try and measure various vital signs like respiratory rate and pulse and infer things, or you could observe the levels of hormones like cortisol in the blood.

Or… you could pull some parts out of a Playstation 4, and get hacking. Edwin Hwu did precisely that, creating a device that can image the skin down to the nanometer and potentially even determine fine details about an individual’s health status. He came to Hackaday Europe 2026 to tell us all about it.

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It’s Teletext, But On The Radio

September 1, 2026 by 18 Comments

Old-school teletext with its pixelated text and block graphics may now be largely a thing of the past, but that doesn’t mean it’s without enthusiasts or there’s no more life in the idea. [M7TJF] has a project which takes teletext and puts it on amateur radio through the magic of AX.25. It’s called CEEFAX Station, in honor of the BBC’s teletext offering from back in the day.

What you get is a Linux package or a Windows executable, which you run and presumably hook the computer up to a radio. It can either be a transmitting node or a receiving one for browsing pages, and there’s an online map to track who’s doing either and on what frequencies. This is all brand new so there’s not much on there at the moment, but we expect that as people try this mode, this will change.

Sadly it’s a little unclear on how the protocol works and how the pages are encoded, but it’s early days. Meanwhile if you hanker for the real thing, it’s still about in some places.

PETG: The PLA Filament Alternative That Just Works

September 1, 2026 by 45 Comments

A typical response to the previous article on why PLA filament is so darn brittle. This has led some people to not use PLA filament at all, while others promote using PLA only for prototyping and throw-away parts, especially in light of PLA being compostable under the right conditions. For many mechanical parts, people turn to PETG.

Much like the PET polymer used for everything from food containers to drink bottles, PETG is durable, more resistant to degradation through mechanisms like hydrolysis and its filament form doesn’t need to be coddled like PLA does. PETG, on the other hand, tends to come from crude oil and shrugs at industrial composting conditions.

In terms of durability, degradation mechanisms and recyclability, is PETG the basic FDM filament which we should all just be using?

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Crowdsourcing An Investigation Into Coil Whine

September 1, 2026 by 27 Comments

If you’ve heard the high-pitched whine or buzz from an electronic device when a current-carrying inductor is vibrating, you’ll know how unpleasant it can be. It’s common in all kinds of equipment, but it’s become a particular annoyance of late in hardware like PC power supplies, GPUs, and cooling pumps. There is plenty of hearsay on the web about which parts whine and which don’t, and [Lowell Wood] wants to get to the bottom of it. 

To track the issue, [Lowell] has put together the Coil Whine Database. It accepts user reports on hardware, regarding the level at which coil whine is present. A score of 0 is given to a part that is inaudible in a quiet room, with higher scores representing higher sound levels. A part scored at 2 is audible working at a desk with the computer under load; a part scored at 4 is audible even when the machine or device is at idle.

For now, the database is largely empty—[Lowell] has just opened submissions, adding a report on their own ROG Astral RTX 5080 card for good measure. If you want to submit a report on a unit, either silent or noisy, that’s simple enough—just fill in the coil whine report form. Over time, submissions will hopefully grow, and it will be easier to get a good idea of what equipment whines and what is likely to operate silently out of the box.

The database aims to present a guide to what parts whine, and how much, noting that any given population of devices tends to vary. To that end, any given device won’t be reported on publicly until it receives at least 5 reports. To counter bias, reports of silent parts will be weighted higher, since it’s unlikely that people happy with their quiet hardware will be rushing to research this issue or report it to a database. Relevant files to the project are available on GitHub for the curious.

This database could be a great boon to the brigade of PC builders out there who like their machines to be as silent as possible. If that sort of thing appeals to you, it’s probably time you started researching passive cooling as well…

open task light

Sliding Into Perfection: The Open Task Light

September 1, 2026 by 28 Comments

A few years ago Dyson released a desk lamp that could slide up and down, in and out, balancing itself at every position. [Steven Bennett] saw that lamp and wanted to make his own. From this passion, the Open Task Light was born.

We covered the prototype of the Open Task Light back in 2023, and the project is a superb example of iteration. In his 15-part video series on the lamp, you can watch him take on each new aspect of the light, improving the mechanisms, electronics, and production. All those small changes add up to this beautifully finished product.

The first thing you’ll notice about the lamp is how little there is to notice: just a pair of extruded aluminum rails with a lamp head on one end and some rollers in the middle. Look a little closer at the rail and you’ll find a PCB running its length, feeding the lamp through pogo pins and leaving no exposed wires. The lamp uses a heat pipe to dump the LED’s heat, again hidden inside the aluminum extrusion. An ESP32 talks to a dedicated LED driver that runs a Cree high-CRI LED. The base comes in several variations for freestanding use or clamping to a table, and it rides on bearings so it can rotate as freely as the lamp’s other axes of movement.

The original lamp this was inspired by carries a hefty price tag, and while the 50-plus-part BOM on this one adds up, it still comes in at well under half the price of its inspiration. The best part: the Open Task Light is open. You can make it your own, head over to [Steven Bennett]’s GitHub to check out the parts. He has also published a well-documented guide on assembling the Open Task Light.

Given the incredible work [Steven] has put into his lamp, we can’t wait to see his next passion project.

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Tricking An Air Conditioner Into Cooling

August 31, 2026 by 23 Comments

Modern heat pumps, of which air conditioners are a subset, seem like simple machines in theory. They just move heat from one place to another. But in order to operate efficiently, they need specific temperatures and humidities on either side of the pump or they can behave in non-ideal ways. [GreatScott!] noticed this when his air conditioner worked well during a heatwave, but started acting anemic once the outside air temperature cooled down. At once point it was barely able to bring his indoor house temperature below the temperature outside, and he went on a deep dive to investigate why this would be and then found a way trick his air conditioner into working outside its designed temperature range.

Many things can cause this behavior, and some of them are indicative of malfunctions like low refrigerant levels or problems with the compressor or control circuitry. But [GreatScott!]’s unit is pretty new so it was unlikely to be something like that. To investigate, he built a circuit with a small heater which is paired to the outdoor heat exchanger’s temperature probe, tricking the control circuitry into working in a different mode. With a few temperature sensors inside and outside, this was enough to kick the air conditioner into high gear and start outputting cold air again.

While noting that we aren’t HVAC experts, there are a few things that could cause this. One of which is high indoor humidity which might be likely for Germany in the summer, or the outdoor condenser needing a certain temperature or pressure range to operate efficiently. Whatever the case, [GreatScott!] decided to remove his creation to keep from inadvertently damaging his air conditioner. It is possible, however, to use a bit of machine learning to find out more about why one’s HVAC system isn’t behaving as well as it should.

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ReactOS Gets An Upgrade

August 31, 2026 by 28 Comments

A perennial in the esoteric operating system space is ReactOS, a project with its roots in the 1990s which is doing a pretty good job of creating an open source clone of 32-bit Windows. They have a new version out, and it’s acquired some useful features.

Top of the list is a new graphical installer, removing the need for separate live and install ISOs, followed by improvements in video bug fixes and high definition audio drivers and subsystems. There’s a headless server install too, in which the GUI is suppressed. Perhaps most interesting, they are working on version syncing the open-source projects such as WINE on which they rely, meaning with luck that any improvements there will show up in ReactOS.

A while back we took a look at using ReactOS as a daily, and found it to be quirks aside, as usable as you’rd expect a Windows XP clone to be. Given that there are plenty of pieces of hardware and software around that still need an early-2000s era Windows to run, this remains an OS to keep an eye on.