Author: Lewin Day

3542 Articles

Giant Neopixel Is Just Like The Regular Kind, Only Bigger

December 15, 2025 by 6 Comments

Neopixels and other forms of addressable LEDs have taken the maker world by storm. They make it trivial to add a ton of controllable, glowing LEDs to any project. [Arnov Sharma] has made a great tribute to the WS2812B LED by building the NeoPixel Giant Edition.

The build is simply a recreation of the standard 5mm x 5mm WS2812B, only scaled up to 150 mm x 150 mm. It uses a WS2811 chip inside to make it behave in the same way from a logical perspective, and this controller is hooked up to nine standard RGB LEDs switched with MOSFETs to ensure they can deliver the requisite light output. The components are all assembled on a white PCB in much the same layout as the tiny parts of a WS2812B, which is then installed inside a 3D-printed housing made in white PLA. Large metal terminals were added to the housing, just like a WS2812B, and the lens was then created using a large dose of clear epoxy.

The result is a fully functional, addressable LED that is approximately 30 times larger than the original. You can even daisy-chain them, just like the real thing. We’ve covered all kinds of projects using addressable LEDs over the years, from glowing cubes to fancy nature installations. If you’ve got your own glowable project that the world needs to see, make sure you notify the tips line!

Pufferfish Venom Can Kill, Or It Can Relieve Pain

December 15, 2025 by 21 Comments

Tetrodotoxin (TTX) is best known as the neurotoxin of the puffer fish, though it also appears in a range of other marine species. You might remember it from an episode of The Simpsons involving a poorly prepared dish at a sushi restaurant. Indeed, it’s a potent thing, as ingesting even tiny amounts can lead to death in short order.

Given its fatal reputation, it might be the last thing you’d expect to be used in a therapeutic context. And yet, tetrodotoxin is proving potentially valuable as a treatment option for dealing with cancer-related pain. It’s a dangerous thing to play with, but it could yet hold promise where other pain relievers simply can’t deliver. Continue reading “Pufferfish Venom Can Kill, Or It Can Relieve Pain” →

Tearing Down Walmart’s $12 Keychain Camera

December 15, 2025 by 47 Comments

Keychain cameras are rarely good. However, in the case of Walmart’s current offering, it might be worse than it’s supposed to be. [FoxTailWhipz] bought the Vivitar-branded device and set about investigating its claim that it could deliver high-resolution photos.

The Vivatar Retro Keychain Camera costs $12.88, and wears “FULL HD” and “14MP” branding on the packaging. It’s actually built by Sakar International, a company that manufactures products for other brands to license. Outside of the branding, though, [FoxTailWhipz] figured the resolution claims were likely misleading. Taking photos quickly showed this was the case, as whatever setting was used, the photos would always come out at 640 x 480, or roughly 0.3 megapixels. He thus decided a teardown would be the best way to determine what was going on inside. You can see it all in the video below.

Pulling the device apart was easy, revealing that the screen and battery are simply attached to the PCB with double-sided tape. With the board removed from the case, the sensor and lens module are visible, with the model number printed on the flex cable. The sensor datasheet tells you what you need to know. It’s a 2-megapixel sensor, capable of resolutions up to 1632 x 1212. The camera firmware itself seems to not even use the full resolution, since it only outputs images at 640 x 480.

It’s not that surprising that an ultra-cheap keychain camera doesn’t meet the outrageous specs on the box. At the same time, it’s sad to see major retailers selling products that can’t do what they say on the tin. We see this problem a lot, in everything from network cables to oscilloscopes.

Continue reading “Tearing Down Walmart’s $12 Keychain Camera” →

All-Screen Keyboard Has Flexible Layouts

December 15, 2025 by 29 Comments

Most keyboards are factory-set for a specific layout, and most users never change from the standard layout for their home locale. As a multilingual person, [Inkbox] wanted a more flexible keyboard. In particular, one with the ability to change its layout both visually and logically, on the fly. Thus was born the all-screen keyboard, which can swap layouts on demand. Have a look at the video below to see the board in action.

The concept is simple enough: It’s a keyboard with transparent keys and a screen underneath. The screen displays the labels for the keys, while the transparent plastic keys provide the physical haptic interface for the typist. The device uses a Raspberry Pi to drive the screen. [Inkbox] then designed a plastic frame and transparent keys, which are fitted with magnets, which in turn are read by Hall effect sensors under the display. This eliminates the need for traditional key switches, which would block light from the screen below.

Unfortunately for [Inkbox], the prototype was very expensive (about $1,400 USD) and not particularly functional as a keyboard. However, a major redesign tackled some of these issues. Version two had a smaller screen with a different aspect ratio. It also jettisoned the Hall effect sensors and uses plastic keys capacitively operating a traditional touch screen. Some design files for the keyboard are available on Github for the curious.

An all-screen keyboard is very cool, if very complicated to implement. There are other ways to change your layout that aren’t quite as fancy, of course. You can always just make custom keycaps and remap layouts on a regular mechanical keyboard if desired. Still, you have to admire the work that went into making this thing a reality.

Continue reading “All-Screen Keyboard Has Flexible Layouts” →

Finally, A Pipe Slapophone With MIDI

December 14, 2025 by 6 Comments

If you live in a major city, you’ve probably seen a street performer with some variety of slapophone. It’s a simple musical instrument that typically uses different lengths of PVC pipe to act as resonant cavities. When struck with an implement like a flip-flop, they release a dull but pleasant tone. [Ivan Miranda] decided to build such an instrument himself and went even further by giving it MIDI capability. Check it out in the video below.

[Ivan’s] design uses a simple trick to provide a wide range of notes without needing a lot of individual pipes. He built four telescoping pipe assemblies, each of which can change length with the aid of a stepper motor and a toothed belt drive. Lengthening the cavity produces a lower note, while shortening it produces a higher note. The four pipe assemblies are electronically controlled to produce notes sent from a MIDI keyboard, all under the command of an Arduino. The pipes are struck by specially constructed paddles made of yoga mats, again controlled by large stepper motors.

The final result is large, power-hungry, and vaguely playable. It’s a little unconventional, though, because moving the pipes takes time. Thus, keypresses on a MIDI keyboard set the pipes to a given note, but don’t actually play it. The slapping of the pipe is then triggered with a drum pad.

We love weird instruments around these parts.

Continue reading “Finally, A Pipe Slapophone With MIDI” →

Get Statistical About Your Pet With This Cat Tracking Dashboard

December 13, 2025 by 3 Comments

Cats can be wonderful companions, but they can also be aloof and boring to hang out with. If you want to get a little more out of the relationship, consider obsessively tracking your cat’s basic statistics with this display from [Matthew Sylvester].

The build is based around the Seeedstudio ReTerminal E1001/E1002 devices—basically an e-paper display with a programmable ESP32-S3 built right in. It’s upon this display that you will see all kinds of feline statistics being logged and graphed. The data itself comes from smart litterboxes, with [Matthew] figuring out how to grab data on weight and litterbox usage via APIs. In particular, he’s got the system working with PetKit gear as well as the Whisker Litter Robot 4. His dashboard can separately track data for four cats and merely needs the right account details to start pulling in data from the relevant cat cloud service.

For [Matthew], the build wasn’t just a bit of fun—it also proved very useful. When one of his cats had a medical issue recently, he was quickly able to pick up that something was wrong and seek the help required. That’s a pretty great result for any homebrew project. It’s unrelated, too, but Gnocci is a great name for a cat, so hats off for that one.

We’ve featured some other fun cat-tracking projects over the years, too. If you’re whipping up your own neat hardware to commune with, entertain, or otherwise interact with your cat, don’t hesitate to let us know on the tipsline.

Hidden Camera Build Proves You Can’t Trust Walnuts

December 12, 2025 by 10 Comments

Typically, if you happened across a walnut lying about, you might consider eating it or throwing it to a friendly squirrel. However, as [Penguin DIY] demonstrates, it’s perfectly possible to turn the humble nut into a clandestine surveillance device. It turns out the walnut worriers were right all along.

The build starts by splitting and hollowing out the walnut. From there, small holes are machined into the mating faces of the walnut, into which [Penguin DIY] glues small neodymium magnets. These allow the walnut to be opened and snapped shut as desired, while remaining indistinguishable from a regular walnut at a distance.

The walnut shell is loaded with nine tiny lithium-polymer cells, for a total of 270 mAh of battery capacity at 3.7 volts. Charging the cells is achieved via a deadbugged TP4056 charge module to save space, with power supplied via a USB C port. Holes are machined in the walnut shell for the USB C port as well as the camera lens, though one imagines the former could have been hidden purely inside for a stealthier look. The camera itself appears to be an all-in-one module with a transmitter built in, with the antenna installed in the top half of the walnut shell and connected via pogo pins. The video signal can be picked up at a distance via a receiver hooked up to a smart phone. No word on longevity, but the included batteries would probably provide an hour or two of transmission over short ranges if you’re lucky.

If you have a walnut tree in your backyard, please do not email us about your conspiracy theories that they are watching you. We get those more than you might think, and they are always upsetting to read. If, however, you’re interested in surveillance devices, we’ve featured projects built for detecting them before with varying levels of success. Video after the break.

Continue reading “Hidden Camera Build Proves You Can’t Trust Walnuts” →