Investigating The Science Claims Behind The Donut Solid State Battery

February 8, 2026 by Maya Posch 12 Comments

Earlier this year Donut Lab caused quite the furore when they unveiled what they claimed was the world’s first production-ready solid state battery, featuring some pretty stellar specifications. Since then many experts and enthusiasts in the battery space have raised concerns that this claimed battery may not be real, or even possible at all. After seeing the battery demonstrated at CES’26 and having his own concerns, [Ziroth] decided to do some investigating on what part of the stated claims actually hold up when subjected to known science.

On paper, the Donut Lab battery sounds amazing: full charge in less than 10 minutes, 400 Wh/kg energy density, 100,000 charge cycles, extremely safe and low cost. Basically it ticks every single box on a battery wish list, yet the problem is that this is all based on Donut’s own claims. Even aside from the concerns also raised in the video about the company itself, pinning down what internal chemistry and configuration would enable this feature set proves to be basically impossible.

In this summary of research done on Donut’s claimed battery as well as current battery research, a number of options were considered, including carbon nanotube-based super capacitors. Yet although this features 418 Wh/kg capacity, this pertains only to the basic material, not the entire battery which would hit something closer to 50 Wh/kg.

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When Clever Hardware Hacks Bite Back: A Password Keeper Device Autopsy

February 7, 2026 by Maya Posch 6 Comments

Sometimes you have this project idea in your mind that seems so simple and straightforward, and which feels just so right that you have to roll with it. Then, years later you stumble across the sad remnants of the tearful saga and the dismal failure that it portrays. Do you put it away again, like an unpleasant memory, or write it up in an article, as a tearful confession of past sins? After some coaxing by a friend, [Alessandro] worked up the courage to detail how he set about making a hardware-only password keeper, and why it failed.

The idea was so simple: the device would pretend to be a keyboard and type the passwords for you. This is not that unusual, as hardware devices like the Mooltipass do something similar. Even better, it’d be constructed only out of parts lying around, including an ATtiny85 and an HD44780 display, with bit-banged USB connectivity.

Prototyping the hardware on a breadboard.

Overcoming the challenge of driving the LC display with one pin on the MCU required adding a 74HC595 demultiplexer and careful timing, which sort of worked when the stars aligned just right. Good enough, but what about adding new passwords?

This is where things quickly skidded off the tracks in the most slapstick way possible, as [Alessandro] solved the problem of USB keyboard HID devices being technically ‘output-only’, by abusing the indicator statuses for Caps Lock, Num Lock, and Scroll Lock. By driving these from the host PC in just the right way you can use them as a sort of serial protocol. This incidentally turned out to be the most reliable part of the project.

Where the project finally tripped and fell down the proverbial flight of stairs was when it came to making the bit-banged USB work reliably. As it turns out, USB is very unforgiving with its timing unlike PS/2, making for an infuriating user experience. After tossing the prototype hardware into a box, this is where the project gathered dust for the past years.

If you want to give it a try yourself, maybe using an MCU that has more GPIO and perhaps even a USB hardware peripheral like the STM32F103, ESP32-S3 or something fruit-flavored, you can take a gander at the project files in the GitHub repository.

We’re always happy to see projects that (ab)use the Lock status indicators, it’s always been one of our favorite keyboard hacks.

A Failed SwitchBot Plug Mini And Cooking Electrolytics

February 7, 2026 by Maya Posch 5 Comments

Poorly designed PCBs and enclosures that slowly cook the electrolytic capacitors within are a common failure scenario in general, but they seem especially prevalent in so-called Internet-of-Things devices. The SwitchBot Plug Mini that [Denki Otaku] took a look at after many reports of them failing is one such example.

The location of the failed electrolytic cap in the SwitchBot Plug Mini. (Credit: Denki Otaku, YouTube)

These Mini Plugs are ‘smart’ plugs that fit into a regular outlet and then allow you to control them remotely, albeit not integrated into a wall or such like the Shelly 2.5 smart relay that also began dying in droves. Yet whereas with the Shelly relays this always seemed to take a few years to show up, generally in the form of WiFi connectivity issues, these SwitchBot plugs sometimes failed within weeks or start constantly switching the relay on and off.

After SwitchBot started an exchange program for these plugs, [Denki Otaku] decided to examine these failed devices from affected users. Inside a dead unit the secondary side’s 680 µF capacitor was clearly bulging and had cooked off its electrolyte as a teardown of a dead capacitor confirmed. After replacing this one capacitor a formerly unresponsive plug sprung back to life.

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Making A DIY Refrigerated Vest With Battery And Solar Power

February 7, 2026 by Maya Posch 27 Comments

Keeping a cool head is difficult at the best of times, least of all when it’s summer and merely thinking of touching bare skin to the pavement already gets you a second-degree burn. Unfortunately, it’s not possible to spend all summer in an air-conditioned room, but what if you took said room with you? Introducing [Hyperspace Pirate]’s air-conditioned vest.

Following on from last time’s adventures with a battery-powered air-conditioner that merely blew cold air onto one’s overheating body, this time the same compressor is used for a more compact build.

Since obviously using your body as part of the condenser would be uncomfortable, instead a heat exchanger was used that transfers the delicious frosty cold to water-filled tubing, zip-tied inside a very fashionable vest.

The basic unit runs on a couple of LiPo packs, but a solar-powered circuit was also built and tested using two small-ish panels. Of course, the requisite backpack-sized setup for that configuration is somewhat bulky, but at least the panels can also provide shade in addition to power for the compressor, hitting two fiery birds with one frosty stone.

Compared to one of those solar-powered caps with a built-in fan, this unit with some refinement could actually be an improvement, as well as keeping you a lot chillier. We’re looking forward to [Hyperspace]’s trial runs in the upcoming Floridian summer, as well as future chilling adventures.

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Why PlayStation Graphics Wobble, Flicker And Twitch

February 6, 2026 by Maya Posch 13 Comments

Although often tossed together into a singular ‘retro game’ aesthetic, the first game consoles that focused on 3D graphics like the Nintendo 64 and Sony PlayStation featured very distinct visuals that make these different systems easy to distinguish. Yet whereas the N64 mostly suffered from a small texture buffer, the PS’s weak graphics hardware necessitated compromises that led to the highly defining jittery and wobbly PlayStation graphics.

These weaknesses of the PlayStation and their results are explored by [LorD of Nerds] in a recent video. Make sure to toggle on subtitles if you do not speak German.

It could be argued that the PlayStation didn’t have a 3D graphics chip at all, just a video chip that could blit primitives and sprites to the framebuffer. This forced PS developers to draw 3D graphics without such niceties like a Z-buffer, putting a lot of extra work on the CPU.

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BreezyBox: A BusyBox-Like Shell And Virtual Terminal For ESP32

February 6, 2026 by Maya Posch 18 Comments

Much like how BusyBox crams many standard Unix commands and a shell into a single executable, so too does BreezyBox provide a similar experience for the ESP32 platform. A demo implementation is also provided, which uses the ESP32-S3 platform as part of the Waveshare 7″ display development board.

Although it invokes the BusyBox name, it’s not meant to be as stand-alone as it uses the standard features provided by the FreeRTOS-based ESP-IDF SDK. In addition to the features provided by ESP-IDF it adds things like a basic virtual terminal, current working directory (CWD) tracking and a gaggle of Unix-style commands, as well as an app installer.

The existing ELF binary loader for the ESP32 is used to run executables either from a local path or a remote one, a local HTTP server is provided and you even get ANSI color support. Some BreezyBox apps can be found here, with them often running on a POSIX-compatible system as well. This includes the xcc700 self-hosted C compiler.

You can get the MIT-licensed code either from the above GitHub project link or install it from the Espressif Component Registry if that’s more your thing.

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How Industrial Robot Safety Was Written In Blood

February 5, 2026 by Maya Posch 33 Comments

It was January 25th of 1979, at an unassuming Michigan Ford Motor Company factory. Productivity over the past years had been skyrocketing due to increased automation, courtesy of Litton Industry’s industrial robots that among other things helped to pick parts from shelves. Unfortunately, on that day there was an issue with the automated inventory system, so Robert Williams was asked to retrieve parts manually.

As he climbed into the third level of the storage rack, he was crushed from behind by the arm of one of the still active one-ton transfer vehicles, killing him instantly. It would take half an hour before his body was discovered, and many years before the manufacturer would be forced to pay damages to his estate in a settlement. He only lived to be twenty-five years old.

Since Robert’s gruesome death, industrial robots have become much safer, with keep-out zones, sensors, and other safety measures. However this didn’t happen overnight; it’s worth going over some of the robot tragedies to see how we got here.

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