Quantum Circuit Uses Just A Few Atoms

June 25, 2022 by Al Williams 5 Comments

Researchers at the University of New South Wales and a startup company, Silicon Quantum Computing, published results of their quantum dot experiments. The circuits use up to 10 carbon-based quantum dots on a silicon substrate. Metal gates control the flow of electrons. The paper appears in Nature and you can download the full paper from there.

What’s new about this is that the dots are precisely arranged to simulate an organic compound, polyacetylene. This allowed researchers to model the actual molecule. Simulating molecules is important in the study of exotic matter phases, such as superconductivity. The interaction of particles inside, for example, a crystalline structure is difficult to simulate using conventional methods. By building a model using quantum techniques on the same scale and with the same topology as the molecule in question, simulation is simplified.

The SSH (Su-Schreffer-Heeger) model describes a single electron moving along a one-dimensional lattice with staggered tunnel couplings. At least, that’s what the paper says and we have to believe it. Creating such a model for simple systems has been feasible, but for a “many body” problem, conventional computing just isn’t up to the task. Currently, the 10 dot model is right at the limit of what a conventional computer can simulate reasonably. The team plans to build a 20 dot circuit that would allow for unique simulations not feasible with classic computing tech.

The dots are made with a scanning tunneling microscope and there is a Goldilocks effect regarding the size of the dots. If they are too small, the energy levels are overwhelmed by phosphorous donors. Too large, and capacitive coupling between dots makes the system unstable.

We’ll admit, the science in the paper is pretty dense. But the Methods section outlines what it takes to create something like this. You’ll need silicon, high-temperature ovens, and the ability to handle exotic gasses and perform lithography. Pretty much an IC fab in your basement. However, we did wonder if anyone homebrewing chips had ever tried STM lithography like this as an alternative to optical lithography. Seems like it might be possible.

We can’t help with some of the more exotic gear, but if you want to build an STM, it has been done. While you can make quantum dots in your kitchen, we don’t think they are going to work the same.

The Prints Don’t Stop With This Prusa I3 MK3 Mod

June 25, 2022 by Matthew Carlson 21 Comments

One of the issues with 3D printing is that when a print is done, you need to go back and pull the print off the bed to reset it for the next one. What if you needed to print 600 little parts for whatever reason? Most people might say get lots of printers and queue them up. Not [Pierre Trappe], as he decided that his Prusa i3 MK3S+ would print continuously.

The setup was dubbed Loop and consisted of a few parts. First, there’s an arm that sweeps the build plate to clear the printed pieces, a slide for the pieces to descend on, and a stand for the printer to sit on that puts it at an angle. The next step is to modify OctoPrint to allow a continuous print queue. The slicer needs to change as [Pierre] provides some G-code to reset the printer and clear the print.

We were especially impressed with the attention to detail in the documentation for this one. There’s extensive guidance on getting the bed adhesion just right, as you can’t have it come off mid-print, but you need it to detach cleanly and easily when the arm sweeps across the bed. Calibrating that first layer is essential, and he provides handy instructions to dial it in. Additionally, temperature and material play a crucial role, and [Pierre] documented the different materials and temperatures he used while developing Loop.

While continuous belt printers are arguably the “correct” answer to the question of printing 600 little parts, they come with their own baggage. Being able to pull off something similar on a printer as reliable and well supported as the Prusa i3 makes for a compelling alternative.

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picture of a brambling (a small bird), with "BirdNET-Pi" written above it

Neural Network Identifies Bird Calls, Even On Your Pi

June 25, 2022 by Arya Voronova 20 Comments

Recently, we’ve stumbled upon the extensive effort that is the BirdNET research platform. BirdNET uses a neural network to identify birds by the sounds they make, and is a joint project between the Cornell Lab of Ornithology and the Chemnitz University of Technology. What strikes us is – this project is impressively featureful and accessible for a variety of applications. No doubt, BirdNET is aiming to become a one-stop shop for identifying birds as they sing.

There’s plenty of ways BirdNET can help you. Starting with likely the most popular option among us, there are iOS and Android apps – giving the microphone-enabled “smart” devices in our pockets a feature even the most app-averse hackers can respect. However, the BirdNET team also talks about bringing sound recognition to our browsers, Raspberry Pi and other SBCs, and even microcontrollers. We can’t wait for someone to bring BirdNET to a RP2040! The code’s open-source, the models are freely available – there’s hardly a use case one couldn’t cover with these.

About that Raspberry Pi version! There’s a sister project called BirdNET-Pi – it’s an easy-to-install software package intended for the Raspberry Pi OS. Having equipped your Pi with a USB sound card, you can make it do 24/7 recording and analysis using a “lite” version of BirdNET. Then, you get a web interface you can log into and see bird sounds identified in real-time. Not just that – BirdNET-Pi also processes the sounds and creates spectrograms, keeps the sound in a database, and can even send you notifications.

The BirdNET-Pi project is open, too, of course. Not just that – the BirdNET-Pi team emphasizes everything being fully local, unless you choose otherwise, and perhaps decide to share it with others. Many do make their BirdNET-Pi instances public, and there’s a lovely interactive map that shows bird sounds all across the world!

BirdNET is, undoubtedly, a high-effort project – and a shining example of what a dedicated research team can do with a neural network and an admirable goal in mind. For many of us who feel joy when we hear birds outside, it’s endearing to know that we can plug a USB sound card into our Pi and learn more about them – even if we can’t spot them or recognize them by sight just yet. We’ve covered bird sound recognition on microcontrollers before – also using machine learning.

A Passive Automatic CNC Tool Changer

June 25, 2022 by Dave Rowntree 18 Comments

[Marius Hornberger] has been busy hacking his “Hammer” CNC router again, and now it sports a much desired feature — an automatic tool-changer. Having wanted one for a while, [Marius] was unhappy sacrificing a big chunk of useable bed area just to park the tool-changer magazine. An obvious solution would be to have the magazine retract away from the bed, outside of the working area. Sadly, the CNC controller had only enough spare outputs to drive the pneumatic tool changer (mounted on the spindle) leaving none spare to control the magazine assembly. So, there was only one obvious route to take, use some simple spring-loaded mechanics to move the magazine into tool-picking range with the Y axis motion instead.

Obviously, the whole thing is CNC machined on the machine itself, taking only a couple of iterations and smidge of table-saw action to get everything to fit well and operate smoothly without binding or colliding with the moving gantry. A cunning pair of levers on each end of the magazine allow it to move much further than the advancing gantry, swinging it quickly into position when the Y axis is at the extreme of its travel, and retracting away when the gantry moves back. Another nice addition to the build was a tool depth sensor (AKA: a switch) mounted off to one side, which allows the machine to find the bottom of each tool, if it is not known, so the Z axis can compensate. When combined with the automatically retracting dust shoe, this is a definitely a CNC build we’d love to see in a shop near us!

We’ve had a fair few CNC hacks over the years, including tool changers, like this one, but 3D printers can use some tool changer love too!

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Giant Xbox Series X Works Like A Real One

June 25, 2022 by Lewin Day 10 Comments

Like most home consoles, the Xbox Series X was specifically designed to fit neatly in the average home theater unit. [Michael Pick] thought that wasn’t quite big enough, and set out to build the world’s largest working Xbox Series X himself.

The build was in part inspired by a Microsoft creation: a large fridge in the shape of an Xbox Series X. However, [Michael] wanted to go further, maintaining the gaming functionality and more faithfully recreating details like the divot on the top of the console.

Carefully positioned servos press the Xbox’s buttons

The first step was to build a big wooden frame, with wooden panels screwed on to create the basic form of the console. Creating the lovely curved and perforated top was done by 3D printing a series of pieces that were all glued together to emulate the feature on the real console itself. The back was also given fake giant ports that look just like the real thing.

The real hack is inside, though. The Xbox hardware itself just sits inside the frame on a little shelf. There’s a handful of servo motors set up to press the real console’s buttons when the corresponding buttons are pressed on the giant Xbox itself. It goes a long way to making the build feel “real” to the user.

The final build measures over 2 meters (6.5 feet) tall and 1 meter wide, weighing in at a total of 113 kg (250 lbs). It was good enough to win [Michael] a Guinness World Record for his trouble. The build was later donated to a local youth center in Georgia.

We’ve seen [Michael]’s giant builds before, too; his 300%-sized Nerf Gun was a particular highlight. Video after the break.

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Hacker Diary: Embedded World 2022

June 25, 2022 by Elliot Williams 11 Comments

Yesterday I went up to the Embedded World trade fair in Nuremburg, Germany. As a lone hacker, you often feel more than a little out of place when you buy chips in single unit quantities and the people you’re talking to are used to minimum order quantities of a million. But what’s heartening is how, once you ask an interesting question, even some of the suit-wearing types flip into full-on kids who like to explain the fun tech. I struck up conversations with more than a couple VPs of global chip behemoths, and they were cool.

But my heart is still with the smaller players, and the hackers. That’s where the innovation is. I met up with Colin O’Flynn, of Chip Whisperer fame — his company is selling fancier chip-glitching tools, but he still had a refined version of the open source, quick-and-dirty zapper circuit from his Remoticon talk last year. There was a small local company producing virtual buttons that were essentially Pepper’s Ghost illusions floating in mid-air, and the button press was detected by reflective IR. Cool tech, but I forgot the company’s name — sorry!

Less forgettable was Dracula Technologies, a French company making inkjet-printable organic solar cells. While they wouldn’t go into deep details about the actual chemistry of what they’re doing, I could tell that it pained them to not tell me when I asked. Anyway, it’s a cool low-power solar tech that would be awesome if it were more widespread. I think they’re just one of many firms in this area; keep your eyes on organic solar.

When talking with a smaller German FPGA manufacturer, Cologne Chip, about their business, I finally asked about the synthesis flow and was happily surprised to hear that they were dedicated to the fully open-source Yosys toolchain. As far as I know, they’re one of the only firms who have voluntarily submitted their chips’ specs to the effort. Very cool! (And a sign of things to come? You can always hope.)

I met a more than a few Hackaday readers just by randomly stumbling around, which also shows that the hacker spirit is alive in companies big and small. All of the companies have to make demos to attract our attention, but from talking to the people who make them, they have just as much fun building them as you or I would.

And last but not least, I ran into Hackaday regular Chris Gammell and my old boss and good friend Mike Szczys who were there representing the IoT startup Golioth, and trying to fool me into using an RTOS on microcontrollers. (Never say never.) We had an awesome walkaround and a great dinner.

If you ever get the chance to go to a trade show like this, even if you feel like you might be out of your league, I encourage you to attend anyway. You’d be surprised how many cool geeks are hiding in the least likely of places.

[Banner image: Embedded World]

NASA Called, They Want Their Cockroaches Back

June 25, 2022 by Al Williams 29 Comments

News hit earlier this month that the infamous “cockroach moon dust” was up for auction? Turns out, NASA is trying to block the sale as they assert that they own all the lunar material brought back from the Apollo missions. What? You didn’t know about cockroach moon dust? Well, it is a long and — frankly — weird story.

It may sound silly now, but there was real concern in 1969 that Apollo 11 might bring back something harmful. So much so that NASA tricked out an RV and kept the astronauts and a volunteer in it for about three weeks after they came home. During that time they were tested and some experiments were done to see if they’d been exposed to anything nasty.

One of those experiments was to feed lunar dust to cockroaches (by the way, the table of contents has a mistake in it — check out page 8). Seriously. But that isn’t even the really weird part. A scientist who worked on the project by the name of Marion Brooks decided she wanted a memento, so she extracted the lunar dust from the dead cockroaches and saved it in a vial. At least we learned a new word: chyme.

RR Auction — the RR stands for Remarkable Rarities — was starting the bidding for some dead cockroaches and a vial of chyme at about 12 grand but it was sure to go higher than that, perhaps up to $400,000 USD. That was before they got a cease and desist from NASA.

It appears the collection has been sold at least once before. NASA has cracked down on anyone selling lunar material as even those given to people are considered on loan from the agency. However, many of the rocks given to different countries and state governments are now unaccounted for.

Back in 2002, interns Thad Roberts and Tiffany Fowler worked in the building where NASA stores most of the moon rocks it has. They took a 600-pound safe containing about 100 grams of moon samples and some other materials. With some help, Roberts tried to fence them to an amateur rock collector who helped the FBI set up a sting. Roberts got over 8 years in federal prison for his efforts, just a little more than an accomplice, Gordon McWhorter, who claimed to have been duped by Roberts. There have been a few other cases of theft, most of which remain unsolved.

This is one of those tricky things. From NASA’s point of view, they own all the moon rocks (with a few exceptions, mostly of material that didn’t come from Apollo). If you steal them, they want them back and if you are given them on loan they don’t appreciate you giving them away, selling them, or losing them. On the other hand, outside of outright theft like the Roberts case, it is hard to imagine that you want to control old roach chyme.

There’s two things we do wonder. First, who saves roach chyme even if it did start as lunar dust? Second, if three little pebbles brought back by the Soviet Luna 16 probe sold for over $850,000 and this dust might have gone for $400,000, why aren’t more of these “New Space” startups scrambling to bring some fresh samples back? Seems like it might pay for itself.