A Modular Macro Keypad

September 26, 2026 by 9 Comments

The introduction of the ATmega32U4 microcontroller, with its integrated USB controller, made a lot of hardware tasks much simpler than they were before. One of the arenas it revolutionized was custom keyboards, making it much easier to build not only standard mechanical keyboards, but keyboards of all kinds of shapes and layouts and custom macro keyboards as well. This trend has continued on for the better part of the past decade with other microcontrollers beyond the 32U4 now available as well, but this modular macro keypad takes it to a new level by keeping that simplicity but also keeping costs down.

The suutari20, as it is called by its creator [Squalius] is able to achieve these aims by using 3.5 mm jacks commonly found in audio equipment. Each jack can support up to three keys, with the hub ultimately able to support 18 different keys. Those can include analog devices as well, such as volume knobs or jog controllers. The macro pad is powered by an RP2040 microcontroller from a Raspberry Pi Pico and uses QMK firmware, so those already familiar with custom keyboard programming will have no problem getting started.

From there, all that’s needed is a case, in this example a 3D printed one, and the commodity audio hardware to plug everything in to. It enables whatever functions can be thought of in a macro pad, and although the design focuses on simplicity and cost, this macro pad takes the concept to the extreme with modular keys that each have their own microcontroller built-in.

Continue reading “A Modular Macro Keypad” →

A grid of screenshots of various applications on the CYD PDA

Cheap Yellow Display Dreams Of PDA

September 26, 2026 by 14 Comments

Everybody loves the Cheap Yellow Display (CYD) ESP32 dev boards, so why not treat yours to a little PDA? That’s right: turn it into a Portable Digital Assistant and relive the glory days of Palm with this project from [sau412].

For those readers who are too young to remember, a PDA was basically a phoneless and cameraless smart-phone, and devices running Palm Corporation’s Palm OS ruled the roost for most of the 90s and early 2000s. [sau412] hasn’t written an emulator or port of Palm OS; rather he’s created his own firmware for the ESP32-based CYD that is inspired by the PDAs of yore, and has many features you’d have expected back in the day. That includes a Gopher browser, to let you check out the undying alternative to the World Wide Web. There isn’t a general-purpose web browser, but there are RSS and Wikipedia readers, and what else do you need? At least you won’t end up doomscrolling.

There are also a passel of games and a BASIC interpreter, and the usual practical things like a calendar, calculator and contact list. Everything from ebook readers to translators, all of it by [sau421]. If you’ve got a CYD kicking around, you could do worse than give it a little PDA. Using the web-based flasher, we had it up and running in five minutes or so, but without an SD card we couldn’t test all the apps.

This is hardly the first ESP32 PDA  that we’ve featured, but leaning into the CYD means it’s the simplest project to replicate.  If you’re jonesing for the original Palm OS experience on more modern hardware, Pumpkin OS can get you going on x86 or ARM.

 

Self-Repairing Conductive Material From Liquid Metal

September 26, 2026 by 4 Comments

PCB circuits are cool, but you know what is cooler? Terminator circuits that’s what! And what if the same material that makes Terminator circuits could also be used for smart heat sinks, flexible circuits, and self-healing material properties? Well, that is exactly what the lab at Virginia Tech’s VT MADE Lab has created, presented by Joel from [3DPrintingNerd].

Continue reading “Self-Repairing Conductive Material From Liquid Metal” →

A Pocket-Sized Digital Fish Tank

September 26, 2026 by 18 Comments

The problem with trying to make a fish tank fit in your pocket is that you’ll either end up with water everywhere or a bunch of dead fish. Perhaps that’s why [StratoBuilds] pursued a digital solution instead.

The concept behind Pocket Tank is relatively simple—it’s a small device that displays a virtual tank with a bunch of little fish swimming around inside. It’s based on the Waveshare ESP32-S3-Touch-AMOLED-1.8, which, if you’re wondering, is an ESP32-S3 with a 1.8″ screen attached, all wrapped up in a convenient plastic housing.

Thanks to the powerful microcontroller, there’s plenty of grunt on tap to run and display a small simulated fish tank. [StratoBuilds] whipped up a system wherein fish movement and animations are handled by regular code running at 25-30 fps, while the fish’s decision making is handled by a custom large language model that was condensed down to run on the ESP32 itself. As the fish swim around the tank, the situation is observed by the LLM and the fish’s current goals are changed accordingly depending on what’s going on. Much like a Tamogotchi, there are regular maintenance tasks for the user to handle, too, like cleaning the tank and feeding the fish to keep them alive.

The blog post and YouTube video do a great job of explaining the project; files are on GitHub for those that wish to tinker more directly. It’s funny, because when we normally look at fish tanks, we’re talking about real ones.

Continue reading “A Pocket-Sized Digital Fish Tank” →

The Least Annoying Of All Evils

September 26, 2026 by 62 Comments

If you missed the hubbub this week, it was discovered that the Raspberry Pi Foundation added code in the firmware that locks the boot process up if non-original RAM chips are detected onboard. Hot-rodding your Pi is a time-honored tradition in these parts. We do wonder just how many folks are taking the risk of hot-airing the memory off the board, versus paying the extra cash to get one with more RAM. But according to Raspberry Pi, enough boards are showing up that have the RAM surreptitiously replaced, and often defective, that they took the step to lock the machine down.

Should users be alerted to potentially unscrupulous behavior by the companies selling them single-board computers? I think we’d all say “sure”. But should that entirely brick the device? And prevent people from upgrading their own? The hacker in me says “no”. Is there any way to reconcile these two? Our own [Arya Voronova] suggests that it’s no big deal to flash an older version of the initial firmware, and we concur, although it does leave behind all the improvements since 2023, and it will only get less fresh as time goes by.

How to announce that the board has non-factory memory without breaking it? [Jeff Geerling] suggested a non-matching-memory bit that users could check, but then they could also neglect to check. My cellphone has a screen that appears every bootup, and requires me to press the power button to continue, because I rooted the phone and installed an open-source OS. It’s a hassle for sure, but it’s a lot better than bricking the phone or disallowing user firmware entirely.

Doing the same thing for the Raspberry Pi isn’t as easy. You never know what, if any, peripherals are connected, so you can’t guarantee that there’s a screen to alert you or even necessarily a keyboard on which you could acknowledge. We’re reminded of a similar situation with FTDI USB-to-serial converter chips ages ago. Their driver software simply refused to work with counterfeit versions of their chips. Hackers were up in arms, largely because we couldn’t know if the parts were genuine at purchase time, and the counterfeits were widely distributed even by reliable resellers.

So what about it? Can you think up a tamper-evident signal that could run on boot on a Raspberry Pi, maybe a headless system installed in some difficult-to-reach place? Maybe ideally the equivalent of the cell phone’s scare message? It would have to be hard to overlook, but keep the machine running, notifying the user that things aren’t kosher, but not preventing them from getting to work. Sounds like a tall order to us.

This article is part of the Hackaday.com newsletter, delivered every seven days for each of the last 200+ weeks. It also includes our favorite articles from the last seven days that you can see on the web version of the newsletter. Want this type of article to hit your inbox every Friday morning? You should sign up!

You Can Make A Microprocessor That’s All Your Own

September 26, 2026 by 7 Comments

For a while now we’ve followed the slow progression of affordable integrated circuit fabrication, and through the likes of Tiny Tapeout we’ve seen impressive strides made. But they’re not the only player in the space, and [Breaking Taps] has a video showing their microprocessor built using wafer.space.

The microprocessor itself is a little unusual, being a transport triggered architecture design with two busses. The whole thing might better be described as a system-on-chip than a microprocessor, as like a microcontroller it contains both memory and peripherals. He’s used Spade to design the thing, and we get an in-depth look at all the steps involved between design and fabrication. It’s a level or two more difficult than passing the DRC standards for your PCB fabricator. The result is a chip carrier with the chip itself visible under clear epoxy. It’s using an old fabrication technology so the silicon is surprisingly big, but unlike Tiny Tapeout’s cell based fabrication the whole chip is the one circuit. Mounting it on a PCB and using a breadboard, he’s able to demonstrate it running simple programs.

It’s clear that having your own IC fabricated is not for everyone, as even though wafer.space has performed minor miracles it’s still a service for people with a few dollars in hand. But look at it this way, we’re still near the start of this particular curve, and we expect that further affordability breakthroughs will follow.

Continue reading “You Can Make A Microprocessor That’s All Your Own” →

Easy Ways To Sink A Hardware Startup

September 26, 2026 by 16 Comments

[Ryan Walker] may have written up his observations a few years ago, but the lessons are just as relevant today as they were back then. He shares five easy ways to sink your hardware startup.

It’s a reminder that while hardware startups are unique, there are basic business realities that still apply because the hardware itself is going to be only one part of a whole. These business fundamentals can be a drag, but it’s worth giving them some attention. But if that’s not your jam, no worries. As [Ryan] experienced, they will explain themselves one way or another.

A good one is skipping market research. Do customers actually exist for this thing? Or forgoing market testing — do the customers actually want it enough to pay for it? One of the worst things to be stuck with is a product that everyone likes, but nobody wants to buy.

Premature optimization is another good one that a number of our readers can probably relate to in one way or another. It’s one thing to buy a tool or a part that one doesn’t end up needing, but when that gets scaled up it can put a real dent in a fledgling business’s development.

We’ve also shared insights on what it takes to develop a product and get it out there, whether as a solo entrepreneur or as part of a larger team, to help nudge the process toward success.