Pi Hand Is A Digital Display Of A Different Sort

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.

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Hackaday Podcast Episode 312: Heart Attacks, The Speed Of Light, And Self-balancing

Elliot does the podcast on the road to Supercon Europe, and Al is in the mood for math and nostalgia this week. Listen in and find out what they were reading on Hackaday this week.

The guys talked about the ESP-32 non-backdoor and battery fires. Then it was on to the hacks.

Self-balancing robots and satellite imaging were the appetizers, but soon they moved on to Kinect cameras in the modern day. Think you can’t travel at the speed of light? Turns out that maybe you already are.

Did you know there was a chatbot in 1957? Well, sort of. For the can’t miss stories: watches monitor your heart and what does the number e really mean?

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in DRM-free MP3 and stream it on the big speakers.

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You Know Pi, But Do You Really Know E?

Pi Day is here! We bet that you know that famous constant to a few decimal points, and you could probably explain what it really means: the ratio of a circle’s circumference to its diameter. But what about the constant e? Sure, you might know it is a transcendental number around 2.72 or so. You probably know it is the base used for natural logarithms. But what does it mean?

The poor number probably needed a better agent. After all, pi is a fun name, easy to remember, with a distinctive Greek letter and lots of pun potential. On the other hand, e is just a letter. Sometimes it is known as Euler’s number, but Leonhard Euler was so prolific that there is also Euler’s constant and a set of Euler numbers, none of which are the same thing. Sometimes, you hear it called Napier’s constant, and it is known that Jacob Bernoulli discovered the number, too. So, even the history of this number is confusing.

But back to math, the number e is the base rate of growth for any continually growing process. That didn’t help? Well, consider that many things grow or decay through growth. For example, a bacteria culture might double every 72 hours. Or a radioactive sample might decay a certain amount per century. Continue reading “You Know Pi, But Do You Really Know E?”

Utah’s FORGE: A Research Laboratory For Enhanced Geothermal Systems

Geothermal heat is a tantalizing source of energy that’s quite literally right below our feet. At the same time geothermal energy is hard to develop as the Earth’s crust is too thick in most places, limiting this to areas where magma is close enough to the surface and the underground rock permeable enough for water. The Utah FORGE facility is a field site were researchers are developing and testing ways to increase the scope of geothermal energy.

An Enhanced Geothermal System (EGS) is designed to be capable of using geothermal energy where this is normally not feasible through a technique that’s reminiscent of the hydraulic fracturing (‘fracking’) used by the oil and gas industry, but rather than creating more fractures, it instead uses hydro-shearing to prop open existing fractures and thus create the through-flow of water needed to extract geothermal energy.

So far FORGE has reported the successful creation of a geothermal reservoir where before there was none. This facility is located in the Milford valley in southwest Utah, which has some hydrothermal activity at the nearby Roosevelt Hot Springs, but through EGS other parts of this valley and similar areas could conceivably be used for generating electricity and for community heating as well. In a 2024 study by University of Utah scientists, it is described how the Milford valley’s volcanic past has left a large body of magma below a thick barrier of granitic rock that could provide access to geothermal resources with EGS to create the requisite fluid permeability.

FORGE is not the only facility working on EGS, but many other sites around the world having ceased activities after issues ranging from induced seismicity, susceptibility to earthquakes and budget shortages. Much like fracking, EGS is likely to cause earthquakes. Whether EGS can be made economically feasible still remains to be seen.

This Week In Security: The X DDoS, The ESP32 Basementdoor, And The CamelCase RCE

We would be remiss if we didn’t address the X Distributed Denial of Service (DDoS) attack that’s been happening this week. It seems like everyone is is trying to make political hay out of the DDoS, but we’re going to set that aside as much as possible and talk about the technical details. Elon made an early statement that X was down due to a cyberattack, with the source IPs tracing back to “the Ukraine area”.

The latest reporting seems to conclude that this was indeed a DDoS, and a threat group named “Dark Storm” has taken credit for the attack. Dark Storm does not seem to be of Ukrainian origin or affiliation.

We’re going to try to read the tea leaves just a bit, but remember that about the only thing we know for sure is that X was unreachable for many users several times this week. This is completely consistent with the suspected DDoS attack. The quirk of modern DDoS attacks is that the IP addresses on the packets are never trustworthy.

There are two broad tactics used for large-scale DDoS attacks, sometimes used simultaneously. The first is the simple botnet. Computers, routers, servers, and cameras around the world have been infected with malware, and then remote controlled to create massive botnets. Those botnets usually come equipped with a DDoS function, allowing the botnet runner to task all the bots with sending traffic to the DDoS victim IPs. That traffic may be UDP packets with spoofed or legitimate source IPs, or it may be TCP Synchronization requests, with spoofed source IPs.

The other common approach is the reflection or amplification attack. This is where a public server can be manipulated into sending unsolicited traffic to a victim IP. It’s usually DNS, where a short message request can return a much larger response. And because DNS uses UDP, it’s trivial to convince the DNS server to send that larger response to a victim’s address, amplifying the attack.

Put these two techniques together, and you have a botnet sending spoofed requests to servers, that unintentionally send the DDoS traffic on to the target. And suddenly it’s understandable why it’s so difficult to nail down attribution for this sort of attack. It may very well be that a botnet with a heavy Ukrainian presence was involved in the attack, which at the same time doesn’t preclude Dark Storm as the originator. The tea leaves are still murky on this one.

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ClockworkPi Unveils New PicoCalc Handheld

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.

The Trials And Tribulations Of Building A Pasta Display

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.

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