Increase Your Blinkenlights With This Silicon Wafer Necklace

November 14, 2023 by 5 Comments

Necklaces aren’t often very high-tech, mostly because of the abuse they have to go through being worn. This was obviously a problem that needed solving, so [Matt Venn] decided to change that by making a necklace out of ASICs just in time for Supercon.

Although this isn’t the first time [Matt] made such a necklace, he though his previous one was “too hip-hop” and not enough “15 million dollar Nikon Lithography Stepper”. Obviously, this means designing the whole chain, art included, from scratch with the blinkenlights to match. Together with [Pat Deegan] and [Adam Zeloof], the team created a beautiful technopunk necklace with art on every chain link and of course a real silicon wafer with a RISC-V tapeout from 2022 on it.

With [Adam] doing modeling for the chain links, and [Pat] and [Matt] designing the electronics required for the mandatory blinkenlights, and some last-minute soldering and assembling the project was finished just in time for Supercon, where it fit right in with all the other blinkenlights. It even runs on one of the RISC-V cores from the same tapeout as the central wafer!

A large, teardrop-shaped van with a wide, friendly face sits in a grassy field. A grey canvas pop top is opened on its top and solar panels extend from either side of its roof, making it look somewhat like a large insect with wings extended.

An Off-Grid EV Camper Van

November 14, 2023 by 34 Comments

Despite our predilection for creature comforts like electricity, it can be nice to get away from it all from time-to-time. Students from Eindhoven University of Technology developed Stella Vita to let you glamp from the power of the sun alone.

Solar-powered vehicles have been plying the highways for decades, but we’re only now getting vehicles with multiple seats that could potentially be used for transport outside of protected race conditions. While production vehicles that can charge off the sun are yet to appear in any appreciable numbers, universities are continuing to push the envelope of what’s possible in a solar car.

Stella Vita is a whale shark-esque camper van designed to be as aerodynamic as possible while still housing all the accoutrements one would want when car camping including a large bed, inductive cooktop, fridge, shower, sink, toilet, and standing room via a pop top. The 2 kW solar array expands to 4 kW when parked via two wings extending from the pop top that also function as awnings for your base camp. By keeping the car lightweight (1,700 kg or 3,700 lb) and aerodynamic, it can go about 600 km (370 mi) on a single charge with its 60 kWh battery.

While it’s still experimental, the team took Stella Vita on a road trip of 3,000 km (1,900 mi) to the south of Spain and were able to get there with only a couple charging stops to account for technical difficulties. A full charge on solar alone takes 2-3 days, which we can see being a convenient amount of time to stop in one spot for your outdoor adventures before heading home or to your next destination.

If you want to build a slightly smaller off-grid camper that’s fueled by coffee instead, you might want to check out this bike camper or this other example.

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There’s No AI In A Markov Chain, But They’re Fun To Play With

November 14, 2023 by 72 Comments

Amid all the hype about AI it sometimes seems as though the world has lost sight of the fact that software such as ChatGPT contains no intelligence. Instead it’s an extremely sophisticated system for extracting plausible machine generated content from the corpus on which it is trained. There’s a long history behind machine generated text, and perhaps the simplest example comes in the form of a Markov chain. [Ben Hoyt] takes us through how these work, and provides some Python code so that you can roll your own.

If you’re uncertain what a Markov chain is, consider the predictive text on your phone. It works by offering the statistically most likely next word in your sentence, and should you accept all of its choices it will deliver sentences which are superficially readable but otherwise complete nonsense. He demonstrates with very simple short source texts how a collocate probability map is generated for two-word phrases, and how from that a likely next word can be extracted. It’s not AI, but it can be a lot of fun to play with and it opens the door to the entire field of computational linguistics. We haven’t set one loose on Hackaday’s archive yet but we suspect it would talk a lot about the Arduino.

We’re talking about Markov chains here with respect to language, but it’s also worth remembering that they work for music too.

Header: Bad AI image with Dall-E prompt, “Ten thousand monkeys with typewriters”.

Testing Various Properties Of LEGO-Compatible Axles

November 14, 2023 by 9 Comments

If you ever wondered what’d happen if you were to use LEGO Technic parts, but they were made out of something other than plastic, the [Brick Experiment Channel] has got you covered. Pitting original Lego axles against their (all except steel commercially available) equivalents made out of carbon fiber, aluminium and steel, some of the (destructive) results are very much expected, while some are more surprising.

Lego-compatible axle test results. (Credit: Brick Experiment Channel, YouTube)

Starting off with the torque test, each type of axle is connected with others and rotated with increasing torque until something gives out. Unsurprisingly, the plastic Technic part fails first and renders itself into a twist, before the carbon fiber version gives up. Aluminium is softer than steel, so ultimately the latter wins, but not before a range of upgrades to the (LEGO-based) testing rig, as these much stronger axles require also strong gears and the like to up the torque.

When it comes to durability, all except the original LEGO version didn’t mind having plastic rubbing against them for a while. Yet for friction in general, the plastic version did better, with less friction. Whether or not this is due to material wearing away is a bit of a question. Overall, stainless steel gets you a lot of strength, but in a dense (8000 kg/m3) package, aluminium comes somewhat close, with 2700 kg/m3, and carbon fiber (1500 kg/m3) does better than the original part (1400 kg/m3), with only a bit more weight, though at roughly ten times the cost.

On that note, we’re looking forward to the first 100% stainless steel LEGO Technic kit, reminiscent of the era when Meccano came in the form of all-metal components and a bucket of bolts.

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Detecting Neutrinos, The Slippery Ghost Particles That Don’t Want To Interact

November 14, 2023 by 62 Comments

Neutrinos are some of the most elusive particles that are well-known to science. These tiny subatomic particles have no electric charge and an extremely small mass, making them incredibly difficult to detect. They are produced in abundance by the sun, as well as by nuclear reactions on Earth and in supernovae. Despite their elusive nature, scientists are keen to detect neutrinos as they can provide valuable information about the processes that produce them.

Neutrinos interact with matter so rarely that it takes a very special kind of detector to catch them in the act. These detectors come in a few different flavors, each employing its unique method to spot these elusive particles. In this article, we’ll take a closer look at how these detectors work and some of the most notable examples of neutrino detectors in the world today.

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D-POINT: A Digital Pen With Optical-Inertial Tracking

November 14, 2023 by 4 Comments

[Jcparkyn] clearly had an interesting topic for their thesis project, and was conscientious enough to write up a chunk of it and release it to the wild. The project in question is a digital pen that uses some neat sensor fusion to combine the inputs from a pen-mounted gyro/accelerometer with data from an optical tracking system provided by an off-the-shelf webcam.

A six degrees of freedom (6DOF) tracking system is achieved as a result, with the pen-mounted hardware tracking orientation and the webcam tracking the 3D position. The pen itself is quite neat, with an ALPS/Alpine HSFPAR003A load sensor measuring the contact pressure transmitted to it from the stylus tip. A Seeed Xaio nRF52840 sense is on duty for Bluetooth and hosting the needed IMU. This handy little module deals with all the details needed for such a high-integration project and even manages the charging of a single 10440 lithium cell via a USB-C connector.

Positional tracking uses Visual Pose Estimation (VPE) assisted with ArUco markers mounted on the end of the stylus. A consumer-grade (i.e. uncalibrated) webcam is all that is required on the hardware side. The software utilizes the familiar OpenCV stack to unroll the effects of the webcam rolling shutter, followed by Perspective-n-Point (PnP) to estimate the pose from the corrected image stream. Finally, a coordinate space conversion is performed to determine the stylus tip position relative to the drawing surface.

The sensor fusion is taken care of with a Kalman filter, smoothed with the typical Rauch-Tung-Striebel (RTS) algorithm before being passed onto the final application. This process is running in Python using the NumPy module, as you would expect, but accelerated using the Numba JIT compiler.

Motion tracking is not news to us, we’ve seen many an implementation over the years, such as this one. But digital input pens? Why aren’t they more of a thing?

Thanks to [Oliver] for the tip!

Pi Zero FPV Robot Uses Tiny Motor & Gears

November 14, 2023 by 4 Comments

We’ve seen plenty of first-person view (FPV) robots built using the Raspberry Pi Zero, but this one from [Shane] has an interesting twist: rather than directly driving the wheels from big motors, it uses small motors and gearboxes to drive the wheels, with some of the gears being 3D printed.

[Shane] has posted the full details of this cute little robot, complete with 3D models, code, and plans for the PCB that connects the Zero to the motors. These motors are N20 ones, which are much smaller and cheaper than what we usually see used in these projects, and run faster. They also often come with a gearbox that reduces the speed to something a bit more useful. Each motor drives the two wheels on one side through a 3D printed gear for tank-style steering.

To run the whole thing off a single LiPo battery, [Shane] also designed his own Pi Hat that converted the voltage to 5 V and added a couple of H bridge chips for the motors. It is a cute little build, but the requirement for a custom Pi hat perhaps puts it beyond most beginners, who might be interested in a cheap, straightforward build like this. Does anybody have any alternatives?

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