It’s not often you’ll see us singing the praises of Microsoft on these pages, but credit where credit is due, this first-person account of how the software giant got its foot in the proverbial door by Bill Gates himself is pretty slick.

Now it’s not the story that has us excited, mind you. It’s the website itself. As you scroll down the page, the text and images morph around in a very pleasing and retro-inspired way. Running your cursor over the text makes it flip through random ASCII characters, reminding us a bit of the “decryption” effect from Sneakers. Even the static images have dithering applied to them as if they’re being rendered on some ancient piece of hardware. We don’t know who’s doing Billy’s web design, but we’d love to have them come refresh our Retro Edition.

Presentation aside, for those who don’t know the story: back in 1975, Gates and Paul Allen told the manufacturer of the Altair 8800 that they had a version of BASIC that would run on the computer and make it easier for people to use. Seeing the potential for increased sales, the company was very interested, and asked them to come give a demonstration of the software in a few weeks.

There was just one problem — Bill and Paul lied. They had never even seen an Altair in person, let alone wrote any code for one. So they set off on a mad dash to complete the project in time, with Allen famously still working on the code on the plane as they flew to the meeting. As you’ve probably guessed, they ended up pulling it off, and the rest is history.

At the very end of the page, you can download the actual source code for Altair BASIC that Gates and Allen co-delivered, presented as scans of the original printout. A little light reading as you wait to find out if that latest Windows update that’s installing is going to tell you that your machine is too old to use anymore.

You can salvage lithium 18650 cells from all sorts of modern gadgets, from disposable vapes to cordless power tools. The tricky part, other than physically liberating them from whatever they are installed in, is figuring out if they’re worth keeping or not. Just because an 18650 cell takes a charge doesn’t necessarily mean it’s any good — it could have vastly reduced capacity, or fail under heavy load.

If you’re going to take salvaging these cells seriously, you should really invest in a charger that is capable of running some capacity tests against the cell. Or if you’re a bit more adventurous, you can build this “Battery Health Monitor” designed by [DIY GUY Chris]. Although the fact that it can only accept a single cell at a time is certainly a limitation if you’ve got a lot of batteries to go though, the fact that it’s portable and only needs a USB-C connection for power means you can take it with you on your salvaging adventures.

The key to this project is a pair of chips from Texas Instruments. The BQ27441 is a “Fuel Gauge” IC, and is able to determine an 18650’s current capacity, which can be compared to the cell’s original design capacity to come up with an estimate of its overall health. The other chip, the BQ24075, keeps an eye on all the charging parameters to make sure the cell is being topped up safely and efficiently.

With these two purpose-built chips doing a lot of the heavy lifting, it only takes a relatively simple microcontroller to tie them together and provide user feedback. In this case [DIY GUY Chris] has gone with the ATmega328P, with a pair of addressable WS2812B LED bars to show the battery’s health and charge levels. As an added bonus, if you plug the device into your computer, it will output charging statistics over the serial port.

The whole project is released under the MIT license, and everything from the STL files for the 3D printed enclosure to the MCU’s Arduino-flavored firmware is provided. If you’re looking to build one yourself, you can either follow along with the step-by-step assembly instructions, or watch the build video below. Or really treat yourself and do both — you deserve it.

If your battery salvaging operation is too large for a single-cell tester, perhaps it’s time to upgrade to this 40-slot wall mounted unit.

Macro pads are handy for opening up your favorite programs or executing commonly used keyboard shortcuts. But why stop there?

That’s what [Jeroen Brinkman] must have been thinking while creating the Programmer’s Macro Pad. Based on the Arduino Pro Micro, this hand-wired pad is unique in that a single press of any of its 16 keys can virtually “type” out multiple lines of text. In this case, it’s a capability that’s being used to prevent the user from having to manually enter in commonly used functions, declarations, and conditional statements.

For example, in the current firmware, pressing the “func” key will type out a boilerplate C function:

int () { //
;
return 0;
}; // f 

It will also enter in the appropriate commands to put the cursor where it needs to be so you can actually enter in the function name. The other keys such as “array” and “if” work the same way, saving the user from having to enter (and potentially, even remember) the correct syntax.

The firmware is kept as simple as possible, meaning that the functionality of each key is currently hardcoded. Some kind of tool that would let you add or change macros without having to manually edit the source code and flash it back to the Arduino would be nice…but hey, it is a Programmers Macro Pad, after all.

Looking to speed up your own day-to-day computer usage? We’ve covered a lot of macro pads over the years, we’re confident at least a few of them should catch your eye.

Getting a look at the internals of a garden variety “wall wart” isn’t the sort of thing that’s likely to excite the average Hackaday reader. You’ve probably cracked one open yourself, and even if you haven’t, you’ve likely got a pretty good idea of what’s inside that sealed up brick of plastic. But sometimes a teardown can be just as much about the journey as it is the end result.

Truth be told, we’re not 100% sure if this teardown from [Brian Dipert] over at EDN was meant as an April Fool’s joke or not. Certainly it was posted on the right day, but the style is close enough to some of his previous work that it’s hard to say. In any event, he’s created a visual feast — never in history has an AC/DC adapter been photographed so completely and tastefully.

[Brian] even goes so far as to include images of the 2.5 lb sledgehammer and paint scraper that he uses to brutally break open the ultrasonic-welded enclosure. The dichotomy between the thoughtful imagery and the savage way [Brian] breaks the device open only adds to the surreal nature of the piece. Truly, the whole thing seems like it should be part of some avant garde installation in SoHo.

After he’s presented more than 20 images of the exterior of the broken wall wart, [Brian] finally gets to looking at the internals. There’s really not much to look at, there’s a few circuit diagrams and an explanation of the theory behind these unregulated power supplies, and then the write-up comes to a close as abruptly as it started.

So does it raise the simple teardown to an art form? We’re not sure, but we know that we’ll never look at a power adapter in quite the same way again.

It’s official, we’re living in the future. Certainly that’s the only explanation for how [wrongbaud] was able to write a three-part series of posts on hacking a cheap electric toothbrush off of AliExpress.

As you might have guessed, this isn’t exactly a hack out of necessity. With a flair for explaining hardware hacking, [wrongbaud] has put this together as a practical “brush-up” (get it?) on the tools and concepts involved in reverse engineering. In this case, the Raspberry Pi is used as a sort of hardware hacking multi-tool, which should make it relatively easy to follow along.

The first post in the series goes over getting the Pi up and running, which includes setting up OpenOCD. From there, [wrongbaud] actually cracks the toothbrush open and starts identifying interesting components, which pretty quickly leads to the discovery of a debug serial port. The next step is harassing the SPI flash chip on the board to extract its contents. As the toothbrush has a high-res color display (of course it does), it turns out this chip holds the images which indicate the various modes of operation. He’s eventually able to determine how the images are stored, inject new graphics data, and write it back to the chip.

Being able to display the Wrencher logo on our toothbrush would already be a win in our book, but [wrongbaud] isn’t done yet. For the last series in the post, he shows how to extract the actual firmware from the microcontroller using OpenOCD. This includes how to analyze the image, modify it, and eventually flash the new version back to the hardware — using that debug port discovered earlier to confirm the patched code is running as expected.

If you like his work with a toothbrush, you’ll love seeing what [wrongbaud] can do with an SSD or even an Xbox controller.

One of the most exciting trends we’ve seen over the last few years is the rise of truly personal computers — that is, bespoke computing devices that are built by individuals to fit their specific needs or wants. The more outlandish of these builds, often inspired by science fiction and sporting non-traditional layouts, tend to be lumped together under the term “cyberdecks”, but there are certainly builds where that description doesn’t quite stick, including the Cyber Writer from [Darbin Orvar].

With a 10-inch screen, you might think it was intended to be a portable, but its laser-cut Baltic birch plywood construction says otherwise. Its overall design reminds us of early computer terminals, and the 60% mechanical keyboard should help reinforce that feeling that you’re working on a substantial piece of gear from yesteryear.

The Cyber Writer is powered by the Raspberry Pi Zero W 2, which might seem a bit underpowered, but [Darbin] has paired it with a custom minimalist word processor. There’s not a lot of detail about the software, but the page for the project says it features integrated file management and easy email export of documents.

The software isn’t yet available to the public, but it sounds like [Darbin] is at least considering it. Granted, there’s already distraction-free writing software out there, but we’re pretty firm believers that there’s no such thing as too many choices.

If you’re looking for something a bit more portable, the impressive Foliodeck might be more your speed.

After seeing some of the interesting clock builds we’ve featured recently, [shiura] decided to throw their hat in the ring and sent us word about their incredible 3D printed hybrid clock that combines analog and digital styles.

While the multiple rotating rings might look complex from the front, the ingenious design behind the mechanism is powered by a single stepper motor. Its operation is well explained in the video below, but the short version is that each ring has a hook that pushes its neighboring ring over to the next digit once it has completed a full rotation. So the rightmost ring rotates freely through 0 to 9, then flips the 10-minute ring to the next number before starting its journey again. This does mean that the minute hand on the analog display makes a leap forward every 10 minutes rather than move smoothly, but we think its a reasonable compromise.

Beyond the 28BYJ-48 geared stepper motor and its driver board, the only other electronics in the build is a Seeed Studio XIAO ESP32C6 microcontroller. The WiFi-enabled MCU is able to pull the current time down from the Internet, but keep it mind it takes quite awhile for the mechanism to move all the wheels; you can see the process happen at 60x speed in the video.

If you’re looking to recreate this beauty, the trickiest part of this whole build might be the 3D print itself, as the design appears to make considerable use of multi-material printing. While it’s not impossible to build the clock with a traditional printer, you’ll have to accept losing some surface detail on the face and performing some well-timed filament swaps.

[shirua] tells us they were inspired to send their timepiece in after seeing the post about the sliding clock that just went out earlier in the week.

A spectrometer is one of those tools that many of us would love to have, but just can’t justify the price of. Sure there are some DIY options out there, but few of them have the convenience or capability of what’s on the commercial market. [Chris] from Zoid Technology recently found a portable spectrometer complete with Android application for just $150 USD on AliExpress which looked very promising…at least at first.

The problem is that the manufacturer, Torch Bearer, offers more expensive models of this spectrometer. In an effort to push users into those higher-priced models, arbitrary features such as data export are blocked in the software. [Chris] first thought he could get around this by reverse engineering the serial data coming from the device (interestingly, the spectrometer ships with a USB-to-serial adapter), but while he got some promising early results, he found that the actual spectrometer data was obfuscated — a graph of the results looked like stacks of LEGOs.

His next step was to decompile the Android application and manually edit out the model number checks. This let him enable the blocked features, although to be fair, he did find that some of them actually did require additional hardware capabilities that this cheaper model apparently doesn’t posses. He was able to fix up a few other wonky issues in the application that are described in the video below, and has released a patch that you can use to bring your own copy of the software up to snuff.

But that’s not all — while fiddling around inside the Android tool’s source code, he found the missing pieces he needed to understand how the serial data was being obfuscated. The explanation to how it works is pretty long-winded, so we’ll save time and just say that the end result was the creation of a Python library that lets you pull data from the spectrometer without relying on any of the manufacturer’s software. This is the kind of thing a lot of people have been waiting for, so we’re eager to see what kind of response the GPLv3 licensed tool gets from the community.

If you’d still rather piece together your own spectrometer, we’ve seen some pretty solid examples you can use to get started.

Another day, another Internet-connected gadget that gets abandoned by its creators. This time it’s Jooki — a screen-free audio player that let kids listen to music and stories by placing specific tokens on top of it. Parents would use a smartphone application to program what each token would do, and that way even very young children could independently select what they wanted to hear.

Well, until the company went bankrupt and shutdown their servers down, anyway. Security researcher [nuit] wrote into share the impressive work they’ve done so far to identify flaws in the Jooki’s firmware, in the hopes that it will inspire others in the community to start poking around inside these devices. While there’s unfortunately not enough here to return these devices to a fully-functional state today, there’s several promising leads.

It probably won’t surprise you to learn the device is running some kind of stripped down Linux, and [nuit] spends the first part of the write-up going over the partitions and peeking around inside the filesystem. From there the post briefly covers how over-the-air (OTA) updates were supposed to work when everything was still online, which may become useful in the future when the community has a new firmware to flash these things with.

Where things really start getting interesting is when the Jooki starts up and exposes its HTTP API to other devices on the local network. There are some promising endpoints such as /flags which let’s you control various aspects of the device, but the real prize is /ll, which is a built-in backdoor that runs whatever command you pass it with root-level permissions! It’s such a ridiculous thing to include in a commercial product that we’d like to think they originally meant to call it /lol, but in any event, it’s a huge boon to anyone looking to dig deeper in to the device.

But wait, there’s more! The Jooki runs a heartbeat script that regularly attempts to check in with the mothership. The expected response when the box pings the server is your standard HTTP 200 OK, but in what appears to be some kind of hacky attempt at implementing a secondary OTA mechanism, any commands sent back in place of the HTTP status code will be executed as root.

Now as any accomplished penguin wrangler will know, if you can run commands as root, it doesn’t take long to fire up an SSH server and get yourself an interactive login. Either of these methods can be used to get into the speaker’s OS, and as [nuit] points out, the second method means that whoever can buy up the Jooki domain name would have remote root access to every speaker out there.

Long story short, it’s horrifyingly easy to get root access on a Jooki speaker. The trick now is figuring out how this access can be used to restore these devices to full functionality. We just recently covered a project which offered a new firmware and self-hosted backend for an abandoned smart display, hopefully something similar for the Jooki isn’t far off.

You take your air quality seriously, so shouldn’t your monitoring hardware? If you’re breathing in nasty VOCs or dust, surely a little blinking LED isn’t enough to express your displeasure with the current situation. Luckily, [Tobias Stanzel] has created the AqMood to provide us with some much-needed anthropomorphic environmental data collection.

To be fair, the AqMood still does have its fair share of LEDs. In fact, one might even say it has several device’s worth of  them — the thirteen addressable LEDs that are run along the inside of the 3D printed diffuser will definitely get your attention. They’re sectioned off in such a way that each segment of the diffuser can indicate a different condition for detected levels of particulates, VOCs, and CO2.

But what really makes this project stand out is the 1.8 inch LCD mounted under the LEDs. This display is used to show various emojis that correspond with the current conditions. Hopefully you’ll see a trio of smiley faces, but if you notice a bit of side-eye, it might be time to crack a window. If you’d like a bit more granular data its possible to switch this display over to a slightly more scientific mode of operation with bar graphs and exact figures…but where’s the fun in that?

[Tobias] has not only shared all the files that are necessary to build your own AqMood, he’s done a fantastic job of documenting each step of the build process. There’s even screenshots to help guide you along when it’s time to flash the firmware to the XIAO Seeed ESP32-S3 at the heart of the AqMood.

If you prefer your air quality monitoring devices be a little less ostentatious, IKEA offers up a few hackable models that might be more your speed.

There’s many different reasons why somebody might have to hack together their own solution to a problem. It could be to save money, or to save time. Occasionally it’s because the problem is unique enough that there might not be an accepted solution, so you’re on your own to create one. We think the situation that [Raph] recently found himself in was a combination of several of these aspects, which makes his success all the sweeter.

The problem? [Raph] had a pair of foam mattresses from his camper van that needed to be made thinner — each of the three inch (7.62 cm) pieces of foam needed to have one inch (2.5 cm) shaved off as neatly and evenly as possible. Trying to pull that off over the length of a mattress with any kind of manual tools was obviously a no-go, so he built a low-rider foam cutter.

With the mattresses laying on the ground, the idea was to have the cutter simply roll across them. The cutter uses a 45″ (115 cm) long 14 AWG nichrome wire that’s held in tension with a tension arm and bungee cords, which is juiced up with a Volteq HY2050EX 50 V 20 A variable DC power supply. [Raph] determined the current experimentally: the wire failed at 20 A, and cutting speed was too low at 12 A. In the end, 15 A seemed to be the sweet spot.

The actual cutting process was quite slow, with [Raph] finding that the best he could do was about 1/8″ (3 mm) per second on the wider of the two mattresses. While the result was a nice flat cut, he does note that at some point the mattresses started to blister, especially when the current was turned up high. We imagine this won’t be a big deal for a mattress though, as you can simply put that side on the bottom.

In the end, the real problem was the smell. As [Raph] later discovered, polyurethane foam is usually cut mechanically, as cutting it with a hot wire gives off nasty fumes. Luckily he had plenty of ventilation when he was making his cuts, but he notes that the mattresses themselves still have a stink to them a couple days later. Hopefully they’ll finish outgassing before his next camping trip.

As you can imagine, we’ve covered a great number of DIY foam cutters over the years, ranging from the very simple to computerized marvels. But even so, there’s something about the project-specific nature of this cutter that we find charming.

Back in 2023, we first brought you word of the PiEEG: a low-cost Raspberry Pi based device designed for detecting and analyzing electroencephalogram (EEG) and other biosignals for the purposes of experimenting with brain-computer interfaces. Developed by [Ildar Rakhmatulin], the hardware has gone through several revisions since then, with this latest incarnation promising to be the most versatile and complete take on the concept yet.

At the core of the project is the PiEEG board itself, which attaches to the Raspberry Pi and allows the single-board computer (SBC) to interface with the necessary electrodes. For safety, the PiEEG and Pi need to remain electrically isolated, so they would have to be powered by a battery. This is no problem while capturing data, as the Pi has enough power to process the incoming signals using the included Python tools, but could be an issue if you wanted to connect the PiEEG system to another computer, say.

For the new PiEEG Kit, the hardware is now enclosed in its own ABS carrying case, which includes an LCD right in the lid. While you’ve still got to provide your own power (such as a USB battery bank), having the on-board display removes the need to connect the Pi to some other system to visualize the data. There’s also a new PCB that allows the connection of additional environmental sensors, breakouts for I2C, SPI, and GPIO, three buttons for user interaction, and an interface for connecting the electrodes that indicates where they should be placed on the body right on the silkscreen.

The crowdsourcing campaign for the PiEEG Kit is set to begin shortly, and the earlier PiEEG-16 hardware is available for purchase currently if you don’t need the fancy new features. Given the fact that the original PiEEG was funded beyond 500% during its campaign in 2023, we imagine there’s going to be plenty of interest in the latest-and-greatest version of this fascinating project.

In 2015, Tim Ellis and Jordan Noone founded Relativity Space around an ambitious goal: to be the first company to put a 3D printed rocket into orbit. While additive manufacturing was already becoming an increasingly important tool in the aerospace industry, the duo believed it could be pushed further than anyone had yet realized.

Rather than assembling a rocket out of smaller printed parts, they imagined the entire rocket being produced on a huge printer. Once the methodology was perfected, they believed rockets could be printed faster and cheaper than they could be traditionally assembled. What’s more, in the far future, Relativity might even be able to produce rockets off-world in fully automated factories. It was a bold idea, to be sure. But then, landing rockets on a barge in the middle of the ocean once seemed pretty far fetched as well.

Of course, printing something the size of an orbital rocket requires an exceptionally large 3D printer, so Relativity Space had to built one. It wasn’t long before the company had gotten to the point where they had successfully tested their printed rocket engine, and were scaling up their processes to print the vehicle’s propellant tanks. In 2018 Bryce Salmi, then an avionics hardware engineer at Relatively Space, gave a talk at Hackaday Supercon detailing the rapid progress the company had made so far.

Just a few years later, in March of 2023, the Relativity’s first completed rocket sat fueled and ready to fly on the launch pad. The Terran 1 rocket wasn’t the entirely printed vehicle that Ellis and Noone had imagined, but with approximately 85% of the booster’s mass being made up of printed parts, it was as close as anyone had ever gotten before.

The launch of Terran 1 was a huge milestone for the company, and even though a problem in the second stage engine prevented the rocket from reaching orbit, the flight proved to critics that a 3D printed rocket could fly and that their manufacturing techniques were sound. Almost immediately, Relativity Space announced they would begin work on a larger and more powerful successor to the Terran 1 which would be more competitive to SpaceX’s Falcon 9.

Now, after an administrative shakeup that saw Tim Ellis replaced as CEO, the company has released a nearly 45 minute long video detailing their plans for the next Terran rocket — and explaining why they won’t be 3D printing it.

Meet the New Boss

For the mainstream press, the biggest story has been that former Google chief Eric Schmidt would be taking over as Relativity’s CEO. Tim Ellis will remain on the company’s board, but likely won’t have much involvement in the day-to-day operation of the company. Similarly, co-founder Jordan Noone stepped down from chief technology officer to take on an advisory role back in 2020.

With the two founders of the company now sidelined, and despite the success of the largely 3D printed Terran 1, the video makes it clear that they’re pursuing a more traditional approach for the new Terran R rocket. At several points in the presentation, senior Relativity staffers explain the importance of remaining agile in the competitive launch market, and caution against letting the company’s historic goals hinder their path forward. They aren’t abandoning additive manufacturing, but it’s no longer the driving force behind the program.

For his part, The New York Times reports that Schmidt made a “significant investment” in Relativity Space to secure controlling interest in the company and his new position as CEO, although the details of the arrangement have so far not been made public. One could easily dismiss this move as Schmidt’s attempt to buy into the so-called “billionaire space race”, but it’s more likely he simply sees it as an investment in a rapidly growing industry.

Even before he came onboard, Relativity Space had amassed nearly $3 billion in launch contracts. Between his considerable contacts in Washington, and his time as the chair of the DoD’s Defense Innovation Advisory Board, it’s likely Schmidt will attempt to put Relativity the running for lucrative government launches as well.

All they need is a reliable rocket, and they’ll have a revenue stream for years.

Outsourcing Your Way to Space

In general, New Space companies like SpaceX and Rocket Lab have been far more open about their design and manufacturing processes than the legacy aerospace players. But even still, the video released by Relativity Space offers an incredibly transparent look at how the company is approaching the design of Terran R.

One of the most interesting aspects of the rocket’s construction is how many key components are being outsourced to vendors. According to the video, Relativity Space has contracted out the manufacturing of the aluminium “domes” that cap off the propellant tanks, the composite overwrapped pressure vessels (COPVs) that hold high pressure helium at cryogenic temperatures, and even the payload fairings.

This isn’t like handing the construction of some minor assemblies off to a local shop — these components are about as flight-critical as you can possibly get. In 2017, SpaceX famously lost one of their Falcon 9 rockets (and its payload) in an explosion on the launch pad due to a flaw in one of the booster’s COPVs. It’s believed the company ultimately brought production of COPVs in-house so they could have complete control of their design and fabrication.

Farming out key components of Terran R to other, more established, aerospace companies is a calculated risk. On one hand, it will allow Relativity Space to accelerate the booster’s development time, and in this case time is very literally money. The sooner Terran R is flying, the sooner it can start bringing in revenue. The trade-off is that their launch operations will become dependent on the performance of said companies. If the vendor producing their fairings runs into a production bottleneck, there’s little Relativity Space can do but wait. Similarly, if the company producing the propellant tank domes decides to raise their prices, that eats into profits.

For the long term security of the project, it would make the most sense for Relativity to produce all of Terran R’s major components themselves. But at least for now, the company is more concerned with getting the vehicle up and running in the most expedient manner possible.

Printing Where it Counts

In some cases, this is where Relativity is still banking on 3D printing in the long term. As explained in the video by Chief Technology Officer Kevin Wu, they initially planned on printing the propellant tank domes out of aluminum, but found that they couldn’t produce them at a fast enough rate to support their targeted launch cadence.

At the same time, the video notes that the state-of-the-art in metal printing is a moving target (in part thanks to their own research and development), and that they are continuing to improve their techniques in parallel to the development of Terran R. It’s not hard to imagine a point in the future where Relativity perfects printing the tank domes and no longer needs to outsource them.

While printing the structural components of the rocket hasn’t exactly worked out as Relativity hoped, they are still fully committed to printing the booster’s Aeon R engines. Printing the engine not only allows for rapid design iteration, but the nature of additive manufacturing makes it easy to implement features such as integrated fluid channels which would be difficult and expensive to produce traditionally.

Of course, Relativity isn’t alone in this regard. Nearly every modern rocket engine is using at least some 3D printed components for precisely the same reasons, and they have been for some time now.

Which in the end, is really the major takeaway from Relativity’s update video. Though the company started out with an audacious goal, and got very close to reaching it, in the end they’ve more or less ended up where everyone else in aerospace finds themselves in 2025. They’ll use additive manufacturing where it makes sense, partner with outside firms when necessary, and use traditional manufacturing methods where they’ve proven to be the most efficient.

It’s not as exciting as saying you’ll put the world’s first 3D printed rocket into space, to be sure. But it’s the path that’s the most likely to get Terran R on the launch pad within the next few years, which is where they desperately need to be if they’ll have any chance of catching up to the commercial launch providers that are already gobbling up large swaths of the market.

Hackaday Europe 2025 is in full swing, and whether you’re experiencing it live in Berlin or following along from home, here’s where you’ll find all the info you need to get the most out of it.

Event Page: https://hackaday.io/europe2025

Chat: Hackaday Discord (Channels: europe-2025 / badge-hacking)

Talk Streams: https://www.youtube.com/@hackaday/streams

Hackers enjoy a good theme, and so it comes as no surprise that every time March 14th (Pi Day) rolls around, the tip line sees an uptick in mathematical activity. Whether it’s something they personally did or some other person’s project they want to bring to our attention, a lot of folks out there are very excited about numbers today.

One of our most prolific circumference aficionados is [Cristiano Monteiro], who, for the last several years, has put together a special project to commemorate the date. For 2025, he’s come up with a robotic hand that will use its fingers to show the digits of Pi one at a time. Since there’s only one hand, anything higher than five will be displayed as two gestures in quick succession, necessitating a bit of addition on the viewer’s part.

[Cristiano] makes no claims about the anatomical accuracy of his creation. Indeed, if your mitts look anything like this, you should seek medical attention immediately. But whether you think of them as fingers or nightmarish claws, it’s the motion of the individual digits that matter.

To that end, each one is attached to an MG90 servo, which an Arduino Nano drives with attached Servo Shield. From there, it’s just a matter of code to get the digits wiggling out the correct value, which [Cristiano] has kindly shared for anyone looking to recreate this project.

If you’re hungry for more Pi, the ghostly display that [Cristiano] sent in last year is definitely worth another look. While not directly related to today’s mathematical festivities, the portable GPS time server he put together back in 2021 is another fantastic build you should check out.

Do you like scientific calculators? Don’t bother answering that question, you’re reading Hackaday so we already know the answer. We also know you’re a fan of building things yourself and open source, which makes us fairly sure you’ll be just as interested in the recently announced ClockworkPi PicoCalc as we are.

On the surface, it looks like a chunky scientific calculator, though on further inspection you’ll note it comes equipped with a QWERTY keyboard. But open up the case and what you’ve really got is an elaborate carrier board for the Raspberry Pi Pico. The PicoCalc supports all variants of the microcontroller, but realistically we can’t think of any reason that you wouldn’t just use the latest version.

With the MCU connected, you’ll have access to the PicoCalc’s 320×320 4-inch IPS screen, backlit I2C-connected keyboard, SD card slot, 8 MB PSRAM, and dual PWM speakers. Power is provided by a pair of 18650 cells (which you’ll need to supply on your own), and the board has the necessary circuitry to charge them up over USB-C.

Everything is housed in an injection molded case, but the project page says all the necessary CAD files will be eventually be released under the GPL v3 so you can 3D print or CNC your own enclosure. For now though, the only thing of note that seems to be in the PicoCalc GitHub repository is a PCB schematic.

The software side of things is a little less clear. The page mentions a BASIC interpreter, MP3 playback, and support for various programming languages, but we get the impression that’s just a list of stuff you can run on the Pi Pico. There are a few images that clearly show the PicoCalc actually being used as a calculator however, so there may be an official firmware yet to be revealed.

The PicoCalc kit is on sale now, and will set you back $75 USD — which actually includes a first-generation Pi Pico, on the off chance that you don’t already have a few laying around. We’ve been impressed with the previous offerings from ClockworkPi, so assuming this new kit maintains that same build quality, it seems like a fair enough price.

We love unique displays here at Hackaday. If you can figure out how to show information on some weird object, we’re all about it. So when [Julius Curt] wrote in to share his work on the Pasta Analog Display, we were hooked from the subject line.

But in reading his account, it ended up being even better than we hoped for. Because it turns out, getting pasta to behave properly in an electromechanical device is trickier than you might think. Oh sure, as [Julius] points out, those ridges on the side of penne might make them look like gears — but after spending the time and effort to build a particularly slick 3D printed frame to actually use them as such, it turns out they just won’t cooperate. You’d think the pasta makers of the world would have some respect for mechanical tolerances, but unfortunately not.

So if [Julius] couldn’t use the natural shape of the penne to get them to rotate, what was the alternative? First, he switched to the far larger cannelloni. Their increased internal volume, most commonly used to hold spinach and ricotta, has in this case been stuffed with a 3D printed armature. Thus each cannelloni is physically attached to a gear, which means when one of them is rotated by a 28BYJ-48 stepper motor, the rest follow.

All that’s left is to apply some artwork to the pasta (again, easier said than done), and rotate them into position. Depending on how much you can cram onto each cannelloni, the display can be rotated to show several different messages. In the video below, [Julius] shows off three distinct images rendered at the push of a button.

If you get hungry while trying to turn pasta into a workable display medium, you can always cook and eat some of your building materials. Luckily, a couple years ago Barilla released the design for an open source device to help you cook their pasta more efficiently.

Hackaday Europe 2025 is just days away, and we’ve got the finalized speaker schedule hot off the digital press. We’re also pleased to announce that the event page is now officially live, where you can find all the vital information about the weekend’s festivities in one place.

Whether you’ll be joining the fun in Berlin, or watching the live stream from home, we’ve got a fantastic lineup of speakers this year who are eager to tell us all about the projects that have been keeping them up at night recently:

Saturday Schedule

Time Has Run Out!

Tickets sold out a few days ago, so if you’ve got one we’ll see you soon, and if not, we will be streaming all of the Saturday talks live, so hit up Hackaday on the weekend and you can play along, at least virtually. And for back-channel chat, join us on the Hackaday Discord #europe-2025 channel.

While the Bus Pirate 5 is an impressive piece of hardware, the software is arguably where the project really shines. Creator [Ian Lesnet] and several members of the community are constantly working to add new features and capabilities to the hardware hacking multi-tool, to the point that if your firmware is more than a few days old there’s an excellent chance there’s a fresher build available for you to try out.

One of the biggest additions from the last week or so of development has been the I2C sniffer — a valuable tool for troubleshooting or reverse engineering devices using the popular communications protocol. [Ian] has posted a brief demo video of it in action.

It’s actually a capability that was available in the “classic” versions of the Bus Pirate, but rather than porting the feature over from the old firmware, [Ian] decided to fold the MIT licensed pico_i2c_sniffer from [Juan Schiavoni] into the new codebase. Thanks to the RP2040’s PIO, the sniffer works at up to 500 kHz, significantly outperforming its predecessor.

Admittedly, I2C sniffing isn’t anything you couldn’t do with a cheap logic analyzer. But that means dealing with captures and making sure the protocol decoder is setup properly, among other bits of software tedium. In comparison, once you start the sniffer program on the Bus Pirate 5, I2C data will be dumped out to the terminal in real-time for as long as you care to see it. For reverse engineering, it’s also very easy to move quickly from sniffing I2C packets to replaying or modifying them within the Bus Pirate’s interface.

If you already have a Bus Pirate 5, all you need to do is flash the latest firmware from the automated build system, and get sniffing. On the fence about picking one up? Perhaps our hands-on review will help change your mind.