DIY Macropad Rocks A Haptic Feedback Wheel

February 5, 2026 by Lewin Day 3 Comments

Macropads can be as simple as a few buttons hooked up to a microcontroller to do the USB HID dance and talk to a PC. However, you can go a lot further, too. [CNCDan] demonstrates this well with his sleek macropad build, which throws haptic feedback into the mix.

The build features six programmable macro buttons, which are situated either on side of a 128×64 OLED display. This setup allows the OLED screen to show icons that explain the functionality of each button. There’s also a nice large rotary knob, surrounded by 20 addressable WS2811 LEDs for visual feedback. Underneath the knob lives an an encoder, as well as a brushless motor typically used in gimbal builds, which is driven by a TMC6300 motor driver board. Everything is laced up to a Waveshare RP2040 Plus devboard which runs the show. It’s responsible for controlling the motors, reading the knob and switches, and speaking USB to the PC that it’s plugged into.

It’s a compact device that nonetheless should prove to be a good productivity booster on the bench. We’ve featured [CNCDan’s] work before, too, such as this nifty DIY VR headset.

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Big Heat Pumps Are Doing Big Things

February 5, 2026 by Lewin Day 56 Comments

The heat pump has become a common fixture in many parts of modern life. We now have reverse-cycle air conditioning, heat pump hot water systems, and even heat pump dryers. These home appliances have all been marketed as upgrades over simpler technologies from the past, and offer improved efficiency and performance for a somewhat-higher purchase price.

Heat pumps aren’t just for the home, though. They’re becoming an increasingly important part of major public works projects, as utility providers try to do ever more with ever less energy in an attempt to save the planet. These days, heat pumps are getting bigger, and will be doing ever grander things in years to come. Continue reading “Big Heat Pumps Are Doing Big Things” →

A VIC-20 Emulator In Your Browser

February 3, 2026 by Lewin Day 11 Comments

The Commodore VIC-20 was a solid microcomputer that paved the way for the legendary Commodore 64 to come. If you’re a fan of the machine and want to revisit its glory days, you could hunt one down on an auction site and hope that it’s in working order. Or you could just emulate the VIC-20 in your browser thanks to the work of [Lance Ewing].

The project is called JVic—because it’s a VIC-20 emulator written in Java. It’s primarily intended for playing old VIC-20 games, and is designed with mobile devices front of mind—so it works well on a phone screen. You can enjoy the built-in library of games, or you can even direct JVic to boot up a ROM from a ZIP file hosted on a given URL or attached to a forum post. You can also install it on your own device rather than running it online, if so desired. [Lance] provides a range of setup options for running it locally or putting it on your own web server if that’s how you like to do things. Files are on Github for those eager to dive in.

We get lots of VIC-20 hacks around these parts. Even if it’s not the most popular machine that Commodore ever built, it’s certainly up there in the rankings. If you want to learn Forth, or even build a VIC-20 from scratch, we’ve explored that before. If you’ve got your own retrocomputer hacks kicking around, don’t hesitate to let us know!

[Thanks to Stephen Walters for the tip!]

Lego Typewriter Writes Plastic Letters

February 3, 2026 by Lewin Day 5 Comments

Some time ago, Lego released a beautiful (and somewhat pricey) typewriter set that was modeled after one used by company founder Ole Kirk Kristiansen. To the disappointment of some, it doesn’t actually work—you can’t really write a letter with it. [Koenkun Bricks] decided to rectify this with their own functional design.

Right away, we’ll state that this is not a traditional typewriter. There are no off-the-shelf Lego components with embossed letters on them, so it wasn’t possible to make Lego type bars that could leave an impression on paper with the use of an inked ribbon. Instead, [Koenkun Bricks] decided to build a design that was Lego all the way down, right to the letters themselves. The complicated keyboard-actuated mechanism picks out flat letter tiles and punches them on to a flat Lego plate, creating a plastic document instead of a paper one.

It’s not perfect in operation. It has some issues unique to its mode of operation. Namely, the round letter tiles sometimes rotate the wrong way as they’re feeding through the typewriter’s mechanisms, so you get sideways letters on your finished document. It looks kind of cool, though. Outside of that, sometimes the letter pusher doesn’t quite seat the letter tiles fully on the document plate.

Overall, though, it’s a highly functional and impressive build. We’ve seen some other great DIY typewriters before, too, like this 3D printed build. Video after the break.

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LED Interior Lighting Could Compromise Human Visual Performance

February 3, 2026 by Lewin Day 66 Comments

LED lighting is now commonplace across homes, businesses, and industrial settings. It uses little energy and provides a great deal of light. However, a new study suggests it may come with a trade-off. New research suggests human vision may not perform at its peak under this particular form of illumination.

The study ran with a small number of subjects (n=22) aged between 23 to 65 years. They were tested prior to the study for normal visual function and good health. Participants worked exclusively under LED lighting, with a select group then later also given supplemental incandescent light (with all its attendant extra wavelengths) in their working area—which appears to have been a typical workshop environment.

*Incandescent bulbs have a much broader spectrum of output than even the best LEDs. Credit: Research paper*

Notably, once incandescent lighting was introduced, those experimental subjects showed significant increases in visual performance using ChromaTest color contrast testing. This was noted across both tritan (blue) and protan (red) axes of the test, which involves picking out characters against a noisy background. Interestingly, the positive effect of the incandescent lighting did not immediately diminish when those individuals returned to using purely LED lighting once again. At tests 4 and 6 weeks after the incandescent lighting was removed, the individuals continued to score higher on the color contrast tests. Similar long-lasting effects have been noted in other studies involving supplementing LED lights with infrared wavelengths, however the boost has only lasted for around 5 days.

The exact mechanism at play here is unknown. The study authors speculate as to a range of complex physical and biological mechanisms that could be at play, but more research will be needed to tease out exactly what’s going on. In any case, it suggests there may be a very real positive effect on vision from the wider range of wavelengths provided by good old incandescent bulbs. As an aside, if you’ve figured out how to get 40/40 vision with a few cheap WS2812Bs, don’t hesitate to notify the tip line.

Thanks to [Keith Olson] for the tip!

CPU Scheduler Divines The Will Of The Heavens

February 1, 2026 by Lewin Day 17 Comments

Horoscopes are a great way to pass a boring lunchbreak, and an excellent excuse for ending a ill-considered relationship. They’re also a hilarious way to handle CPU scheduling under Linux, thanks to the work of [Lucas Zampieri].

The project is called scx_horoscope, and it’s a sched_Ext scheduler that makes its CPU scheduling choices based on what the heavens are doing in real time. Different tasks are handled based on different astronomical objects. For example, the Sun represents life force, and thus grants boons to key system processes. The Moon, an emotive influence, rules over interactive processes like shells and terminals. Mercury, as the god of communication, handles network and IO tasks, and so it goes from there. It’s not just a surface level thing, either—[Lucas] has implemented the influences of the elements of fire, air, earth, and water, and there are negative timeslice penalties on associated tasks when a given planet lands in retrograde.

You can argue whether or not the broader motions of the heavens have any impact on our lives based on the time and circumstances of our birth. But you can’t argue that scx_horoscope really will influence how your computer runs based on the dance of the planets in the sky. Mostly, though, we concern ourselves with astronomy rather than astrology around these parts!

[Thanks to Benjamin for the tip!]

A DIY Headset For SteamVR

February 1, 2026 by Lewin Day 1 Comment

The modern era of VR started a long time ago, and a wide range of commercial headsets have proliferated on the market since then. If you don’t want to buy off the shelf, though, you could always follow [Manolo]’s example and build your own.

This DIY headset is known as the Persephone 3 Lite, and is intended for use with SteamVR. It’s got the requisite motion tracking thanks to a Raspberry Pi Pico, paired with an MPU6500 inertial measurement unit. As for the optics, the headset relies on a pair of 2.9-inch square displays that operate at a resolution of 1440 x 1440 with a refresh rate up to 90 Hz. They’re paired with cheap Fresnel lenses sourced from Aliexpress for a few dollars. Everything is wrapped up in a custom 3D-printed housing that holds all the relevant pieces in the right place so that your eyes can focus on both screens at once. The head strap is perhaps the only off-the-shelf piece, sourced from a Quest 2 device.

If you’re eager to recreate this build at home, files are available over on [Manolo’s] Patreon page for subscribers. We’ve featured some other DIY headset builds before, too. Video after the break.

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