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Hackaday Links: August 23, 2026

We’ll start this week off with some disappointing, though not entirely unexpected, news — the ambitious commercial mission to save NASA’s Neil Gehrels Swift Observatory is officially a bust. The space agency provided an update earlier this week explaining that the attitude control issues with the LINK spacecraft that started a few weeks after it launched will prevent it from being able to safely dock with the Swift Observatory and boost its altitude. As such, the space telescope is now expected to reenter the Earth’s atmosphere and burn up before the end of the year.

Although LINK won’t be able to live up to its name, NASA did say operator Katalyst Space has been given permission to continue with the rendezvous attempt. The two craft won’t actually make contact with each other, but teams on both sides feel there’s lessons to be learned and data to be collected by seeing the orbital dance of these two vehicles play out for as long as possible.

Speaking of hardware that couldn’t quite hit its design goals, TechCrunch is reporting that a class action lawsuit has been filed against Oura by customers that say the company made misleading claims about the sleep-tracking accuracy of their smart rings. Namely, that the rings could somehow detect which stage of sleep the wearer was in with only the pulse and temperature sensors it has onboard.

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A small mood/busy indicator attached to a laptop.

Personal Traffic Light Stops Them In Their Tracks

Working from home can be pretty cool, but if you’re not the only one in the house trying to do it, the whole situation can feel like you’re right back in the office with all those walking, talking distractions. Except they’re in pajamas instead of business casual.

The parts needed to build this mood indicator.So, what’s the answer? Many times it’s not practical to stop what you’re doing, especially just to communicate that you’re busy. We suppose you could glare at them, put up your hand, or even give a dismissive wave, but a better solution might be this mood signal built by [gokux].

Through a simple web app, you can be red to indicate that you’re super busy, yellow to mean busy-ish, and green for let’s gossip about the cats.

This mood indicator is built on the Seeed Xiao ESP32-C3 and shows the given mood indicator on a small matrix of sixteen WS2812B LEDs. It’s powered by a 600 mAh, 3.7 V battery and a small push button switch. As usual, [gokux] has grade-A instructions for building your own version of this slick solution.

Would you like something more tactile and low-tech? Check out our own [Bob Baddeley]’s free/busy indicator from the lockdown days.

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Folding Typewriter

Have you built yourself a macro pad yet? They’re all sorts of programmable fun, whether you game, stream, or just plain work, and there are tons of ideas out there.

A DIY macro pad with key switches, dual linear pots, a rotary encoder, a screen, and a speaker.
Image by [CiferTech] via Hackaday.IO
But if you don’t want to re-invent the wheel, [CiferTech]’s MicroClick (or MacroClick — the jury is still out) might be just what you need to get started straight down the keyboard rabbit hole.

This baby runs on an ATmega32U4, which known for its Human Interface Device (HID) capabilities. [CiferTech] went with my own personal favorite, blue switches, but of course, the choice is yours.

There are not one but two linear potentiometers for volume, and these are integrated with WS2812 LEDs to show where you are, loudness-wise. For everything else, there’s an SSD1306 OLED display.

But that’s not all — there’s a secondary microcontroller, an ESP8266-07 module that in the current build serves as a packet monitor. There’s also a rotary encoder for navigating menus and such. Make it yours, and show us!

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A persistence-of-vision business card which displays information when shaken (not stirred).

2024 Business Card Challenge: Make Them Shake Your Handiwork

Before COVID, people traditionally sealed their initial introduction to each other with a handshake. Nowadays, that activity seems kind of questionable. But you can still give them something to shake if you build this persistence of vision (POV) business card from [chaosneon] to show your credentials in blinkenlights form.

As you might have guessed, the input comes from a tilt switch. The user simply shakes the card back and forth, and the sensor detects the direction and cadence of the shake. Cleverly, the pattern plays forward-ways on the swing, and backwards on the back stroke, which just reinforces the POV effect. Don’t worry about how slow or fast to shake it, because the timing adjusts for your speed.

The first version used individual white LEDs, hand-soldered to an ATtiny2313. Now, in the updated version which you can see in the demo video after the break, [chaosneon] is using an RGB NeoPixel strip, which only needs one data wire to connect to the microcontroller. Thanks to this, [chaosneon] was able to to downsize to an ATtiny85.

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Linear LED clock displaying the time using different-colored triangles.

Linear LED Clock Looks Decidedly Vintage

We just love a good clock around here, and something about those triangles gives this linear LED clock a deliciously mid-century vibe. If you’ve read these pages for any length of time, you know that [andrei.erdei] loves clocks as much as we do, and is always coming up with interesting ways of displaying the passage of time.

Two upward-facing triangles sandwich one downward-facing triangle, and they are lighting up as follows: right, left, middle.This one is a remix of some other linear RGB clocks, but the result is distinctly [andrei.erdei]’s style. There’s nothing crazy going on under the hood here — it’s essentially a Wemos D1 mini running a strip of RGBs, and the microcontroller connects to a Wi-Fi router to get the time from a server. The magic is in the programming and the way the clock is read.

The brief but thorough demo video after the break does a much better job of explaining the display by showing various times of the day, but we’ll give it a shot. For one thing, it uses 24-hour time exclusively. There are four groups of triangles; yellow, red, green, and blue which correspond to tens and units of hours, and tens and units of minutes.

The triangles light up in groups of three in the order depicted in the animation. At midnight, none of the triangles are lit up. Again, it’s best explained in the video, looking at various times of day.  Plus you can see the neat-o startup animation.

Are you more into sound than blinkenlights? Then this customizable bird clock may be for you.

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An RGB LED clock that resembles a color blindness test.

RGB LED HexaClock Doesn’t Actually Light Up The Night

Who says a clock can’t be both useful and beautiful? That seems to be the big idea behind the lovely little HexaClock from [Bulduper]. And boy, is it both.

Probably the most important part of this well-illuminated clock is the light sensor, which allows it to adjust the brightness automatically. If you’re not into that, well, there’s a really nice web app that’ll let you program the dickens out of it.

The brains of this thing is an ESP8266 on a custom PCB which controls the 127 individually addressable RGB LEDs. The clock may look large, but the big printed parts just fit on the bed of a Prusa i3. [Bulduper] used ABS because the LED strip and the PCB might get a little warm; they didn’t want to risk using PLA and having it turn into a Salvador Dali clock (although that could be cool).

Speaking of heat, make sure to use 18 AWG or thicker wires as [Bulduper] advises. LEDs may be efficient, but this clock uses lots of them! If you want to build one of these to bathe your wall in useful light, everything you need is available on GitHub. Watch HexaClock do its thing in the brief demo and walk-through video after the break.

If this is a little too bright for your tastes, check out this synesthesia clock.

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Cyberpunk Guitar Strap Lights Up With Repurposed PCBs

Sometimes, whether we like it or not, ordering PCBs results in extra PCBs lying around, either because of board house minimums, mistakes on either end, or both. What’s to be done with these boards? If you’re Hackaday alum [Jeremy Cook], you make a sound-reactive, light-up guitar strap and rock out in cyberpunk style.

The PCBs in question were left over from [Jeremy]’s JC Pro Macro project, and each have four addressable RGB LEDs on board. These were easy enough to chain together with jumper wires, solder, and a decent amount of hot glue. Here’s a hot tip: you can use compressed air to rapidly cool hot glue if you turn the can upside down. Just don’t spray it on your fingers.

The brains of this operation is Adafruit Circuit Playground Express, which runs off of a lipstick battery and conveniently brings a microphone to the table. These two are united by a 3D print, which is hot-glued to the guitar strap along with all the boards. In the second video after the break, there’s a bonus easy-to-make version that uses an RGB LED strip in place of the repurposed PCBs. There’s no solder or even hot glue involved.

Want to really light up the night? Print yourself a sound-reactive LED guitar.

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