Perfecting The Shape-Changing Fruit Bowl

March 13, 2026 by Tyler August 3 Comments

Fruit bowls have an unavoidable annoyance– not flies and rotten fruit, those would be avoidable if your diet was better. No, it’s that the bowl is never the right size. Either your fruit is sad and lonely in a too-large bowl, or it’s falling out. It’s the kind of existential nightmare that can only be properly illustrated by a late-night infomercial. [Simone Giertz] has a solution to the problem: a shape-changing fruit bowl.

See, it was one thing to make a bowl that could change shape. That was easy, [Simone] had multiple working prototypes. There are probably many ways to do it, but we like [Simone]’s use of an iris mechanism in a flat base to allow radial expansion of the walls. The problem was that [Simone] has that whole designer thing going on, and needs the bowl to be not only functional, but aesthetically pleasing. Oh, and it would be nice if expanding the bowl didn’t create escape routes for smaller fruits, but that got solved many prototypes before it got pretty.

It’s neat to see her design process. Using 3D printing and CNC machining for prototyping is very familiar to Hackaday, but lets be honest — for our own projects, it’s pretty common to stop at “functional”. Watching [Simone] struggle to balance aesthetics with design-for-manufacturing makes for an interesting 15 minutes, if nothing else. Plus she gives us our inspirational quote of the day: “As much as I feel like I’m walking in circles, I know that product development is a spiral”. Something to keep in mind next time it seems like you’re going around the drain in your own projects. Just be warned, she does have a bit of a potty mouth.

We’ve featured [Simone]’s design decisions here, if you’re interested in seeing how she goes the rest of the way from project to product. We’re pretty sure her face-slapping-alarm clock never made it into the SkyMall catalog, though.

Continue reading “Perfecting The Shape-Changing Fruit Bowl” →

Power Control For A Busy Workbench

March 10, 2026 by Jenny List 30 Comments

Who among us does not have a plethora of mains-powered devices on their workbench, and a consequent mess of power strips to run them all? [Jeroen Brinkman] made his more controllable with a multi-way switch box.

At first sight it’s a bank of toggle switches, one for each socket. But this is far more than a wiring job, because of course there are a couple of microcontrollers involved, and each of those switches ultimately controls a relay. There are also status LEDs for each socket, and a master switch to bring them all down. Arduino code is provided, so you can build one too if you want to.

We like the idea of a handy power strip controller, and especially the master switch with the inherent state memory provided by the switches. This could find a home on a Hackaday bench, and we suspect on many others too. It’s by no means the first power strip with brains we’ve seen, but most others have been aimed at the home instead.

Railway End Table Powered By Hand Crank

March 5, 2026 by Lewin Day 10 Comments

Most end tables that you might find in a home are relatively static objects. However, [Peter Waldraff] of Tiny World Studios likes to build furniture that’s a little more interesting. Thus came about this beautiful piece with a real working railway built right in.

The end table was built from scratch, with [Peter] going through all the woodworking steps required to assemble the piece. The three-legged wooden table is topped with a tiny N-scale model railway layout, and you get to see it put together including the rocks, the grass, and a beautiful epoxy river complete with a bridge. The railway runs a Kato Pocket Line trolley, but the really neat thing is how it’s powered.

[Peter] shows us how a small gearmotor generator was paired with a bridge rectifier and a buck converter to fill up a super capacitor that runs the train and lights up the tree on the table. Just 25 seconds of cranking will run the train anywhere from 4 to 10 minutes depending on if the tree is lit as well. To top it all off, there’s even a perfect coaster spot for [Peter]’s beverage of choice.

It’s a beautiful kinetic sculpture and a really fun way to build a small model railway that fits perfectly in the home. We’ve featured some other great model railway builds before, too.

Continue reading “Railway End Table Powered By Hand Crank” →

The metal comm badge and M5stick on an LCARS mousepad

Control Your Smart Home With Trek-Inspired Comm Badge

February 25, 2026 by Tyler August 38 Comments

One thing some people hate about voice control is that you need to have a process always running, listening for the wake word. If your system isn’t totally locally-hosted, that can raise some privacy eyebrows. Perhaps that’s part of what inspired [SpannerSpencer] to create this 24th century solution: a Comm Badge straight out of Star Trek: The Next Generation he uses to control his smart home.

This hack is as slick as it is simple. The shiny comm badge is actually metal, purchased from an online vendor that surely pays all appropriate license fees to Paramount. It was designed for magnetic mounting, and you know what else has a magnet to stick it to things? The M5StickC PLUS2, a handy ESP32 dev kit. Since the M5Stick is worn under the shirt, its magnet attached to the comm badge, some features (like the touchscreen) are unused, but that’s okay. You use what you have, and we can’t argue with how easy the hardware side of this hack comes together.

[Spanner] reports that taps to the comm badge are easily detected by the onboard accelerometer, and that the M5Stick’s microphone has no trouble picking up his voice. If the voice recordings are slightly muffled by his shirt, the Groq transcription API being used doesn’t seem to notice. From Groq, those transcriptions are sent to [Spanner]’s Home Assistant as natural language commands. Code for the com-badge portion is available via GitHub; presumably if you’re the kind of person who wants this, you either have HA set up or can figure out how.

It seems worth pointing out that the computer in Star Trek: TNG did have a wake word: “computer”. On the other hand it seemed the badges were used to interface with it just as much as the wake word on screen, so this use case is still show accurate. You can watch it in the demo video below, but alas, at no point does his Home Assistant talk back. We can only hope he’s trained a text-to-speech model to sound like Majel Barrett-Roddenberry. At least it gives the proper “beep” when receiving a command.

This would pair very nicely with the LCARS dashboard we featured in January. Continue reading “Control Your Smart Home With Trek-Inspired Comm Badge” →

Making A Hidden Door Status Sensor

February 10, 2026 by Maya Posch 29 Comments

The door sensor in its new enclosures. (Credit: Dillan Stock)

A common sight in ‘smart homes’, door sensors allow you to detect whether a door is closed or open, enabling the triggering of specific events. Unfortunately, most solutions for these sensors are relatively bulky and hard to miss, making them a bit of a eyesore. This was the case for [Dillan Stock] as well, who decided that he could definitely have a smart home, yet not have warts sticking out on every single doorframe and door. There’s also a video version of the linked blog post.

These door sensors tend to be very simple devices, usually just a magnet and a reed relay, the latter signaling a status change to the wireless transmitter or transceiver. Although [Dillan] had come across recessed door sensors before, like a Z-wave-based unit from Aeotec, this was a very poorly designed product with serious reliability issues.

That’s when [Dillan] realized that he could simply take the PCB from one of the Aqara T1 door sensors that he already had and stuff them into a similar 20 mm diameter form factor as that dodgy sensor unit. Basically this just stuffs the magnet and PCB from an existing wart-style sensor into a recessed form factor, making it a very straightforward hack, that only requires printing the housings for the Aqara T1 sensor and some intimate time between the door and a drill.

Continue reading “Making A Hidden Door Status Sensor” →

Habit Detection For Home Assistant

February 8, 2026 by Lewin Day 15 Comments

Computers are very good at doing exactly what they’re told. They’re still not very good at coming up with helpful suggestions of their own. They’re very much more about following instructions than using intuition; we still don’t have a digital version of Jeeves to aid our bumbling Wooster selves. [Sherrin] has developed something a little bit intelligent, though, in the form of a habit detector for use with Home Assistant.

In [Sherrin]’s smart home setup, there are lots of things that they wanted to fully automate, but they never got around to implementing proper automations in Home Assistant. Their wife also wanted to automate things without having to get into writing YAML directly. Thus, they implemented a sidecar which watches the actions taken in Home Assistant.

The resulting tool is named TaraHome. When it detects repetitive actions that happen with a certain regularity, it pops up and suggests automating the task. For example, if it detects lights always being dimmed when media is playing, or doors always being locked at night, it will ask if that task should be set to happen automatically and can whip up YAML to suit. The system is hosted on the local Home Assistant instance. It can be paired with an LLM to handle more complicated automations or specific requests, though this does require inviting cloud services into the equation.

We’ve featured lots of great Home Assistant hacks over the years, like this project that bridges 433 MHz gear to the smart home system. If you’ve found your own ways to make your DIY smart home more intelligent, don’t hesitate to notify the tipsline!

Make Your Own ESP32-Based Person Sensor, No Special Hardware Needed

January 28, 2026 by Donald Papp 24 Comments

Home automation with high usefulness and low annoyance tends to rely on reliable person sensing, and [francescopace]’s ESPectre shows one way to do that cheaply and easily by leveraging hardware that’s already present on a common dev board.

ESPectre is an ESP32-based open source motion detector that detects movement without any cameras or microphones. It works similarly to millimeter-wave (mmWave) radar motion detectors in the sense that when a person moves, wireless signals are altered slightly as a result. ESPectre can detect this disturbance by watching and analyzing the Wi-Fi channel state information (CSI) and doing some very smart math and filtering. It’s cheap, easy to deploy and use, and even integrates with Home Assistant.

Combining a sensor like this with something else like a passive infrared (PIR) motion sensor is one way to get really robust results. But keep in mind that PIR only senses what it can see, whereas ESPectre works on WiFi, which can penetrate walls.

Since ESPectre supports low-cost ESP32 variants and is so simple to get up and running, it might be worth your time to give it a trial run. There’s even a browser-based ghost-dodging game [francescopace] put online that uses an ESPectre board plugged in over USB, which seems like a fun way to get a feel for what it can do.