During the AI research boom of the 1970s, the LISP language – from LISt Processor – saw a major surge in use and development, including many dialects being developed. One of these dialects was Scheme, developed by [Guy L. Steele] and [Gerald Jay Sussman], who wrote a number of articles that were published by the Massachusetts Institute of Technology (MIT) AI Lab as part of the AI Memos. This subset, called the Lambda Papers, cover the ideas from both men about lambda calculus, its application with LISP and ultimately the 1980 paper on the design of a LISP-based microprocessor.

Scheme is notable here because it influenced the development of what would be standardized in 1994 as Common Lisp, which is what can be called ‘modern Lisp’. The idea of creating dedicated LISP machines was not a new one, driven by the processing requirements of AI systems. The mismatch between the S-expressions of LISP and the typical way that assembly uses the CPUs of the era led to the development of CPUs with dedicated hardware support for LISP.

The design described by [Steele] and [Sussman] in their 1980 paper, as featured in the Communications of the ACM, features an instruction set architecture (ISA) that matches the LISP language more closely. As described, it is effectively a hardware-based LISP interpreter, implemented in a VLSI chip, called the SCHEME-78. By moving as much as possible into hardware, obviously performance is much improved. This is somewhat like how today’s AI boom is based around dedicated vector processors that excel at inference, unlike generic CPUs.

During the 1980s LISP machines began to integrate more and more hardware features, with the Symbolics and LMI systems featuring heavily. Later these systems also began to be marketed towards non-AI uses like 3D modelling and computer graphics. As however funding for AI research dried up and commodity hardware began to outpace specialized processors, so too did these systems vanish.

Top image: Symbolics 3620 and LMI Lambda Lisp machines (Credit: Jason Riedy)

Vector Control, also known as Field Oriented Control or FOC is an AC motor control scheme that enables fine-grained control over a connected motor, through the precise control of its phases. In a recent video [Excessive Overkill] goes through the basics and then the finer details of how FOC works, as well as how to implement it. These controllers generally uses a proportional integral (PI) loop, capable of measuring and integrating the position of the connected motor, thus allowing for precise adjustments of the applied vector.

If this controller looks familiar, it is because we featured it previously in the context of reviving old industrial robotic arms. Whether you are driving the big motors on an industrial robot, or a much smaller permanent magnet AC (PMAC) motor, FOV is very likely the control mechanism that you want to use for the best results. Of note is that most BLDC motors are actually also PMACs with ESC to provide a DC interface.

The actual driving is done with two MOSFETs per phase, forming a half-bridge, switching between the two rails to create the requisite PWM signal for each phase. Picking the right type of MOSFET was somewhat hard, especially due to the high switching currents and the high frequency at 25 kHz. The latter was picked to prevent audible noise while driving a robot. Ultimately SiC MOSFETs were picked, specially the GeneSiC G3R30MT12K. Of note here are the four legs, with a fourth Kelvin Source pin added. This is to deal with potential gate drive issues that are explained in the video.

With the hardware in place, whether following the [Excessive Overkill] GitHub projects or not, what makes all of it work is the software. This is where the microcontroller aspect is essential, as it has to do all the heavy lifting of calculating the new optimal vector and thus the current levels per phase. In this controller an STM32F413 is used, which generates the PWM signals to drive the half-bridges, while reading the measurements from the motors with its ADC.

As can be seen in the resulting use of this controller with old industrial robots, the FOC controller works quite well, with quiet and smooth operation. This performance is why we’re likely to see FOC and PMAC motors used in applications like 3D printers in the future, though the rule of ‘good enough’ makes the cost of an FOC controller still a tough upsell over a simple open loop stepper-based system.

Carnivorous plants are a fascinating part of the natural world, especially species like the Venus flytrap (Dionaea muscipula) that rely on what is effectively a spring-loaded trap to ensnare unsuspecting prey. As also seen with species like the waterwheel plant (Aldrovanda vesiculosa), species like sundews are a lot more chill with movement in the order of seconds, excluding D. glanduligera which displays a similar sub-second response as the Venus flytrap. Over the years there has been much speculation about the exact mechanism that enables such a fast response, with [Hiraku Suda] and colleagues offering an explanation, via a recently published paper in Nature Communications.

The sensory hairs that line the Venus flytrap’s leaves are finely tuned to respond to certain kind of stimuli using calcium threshold signals. This is something which was previously known already, but the exact mechanism still proved to be elusive.

This new study shows that a mechanosensor called DmMSL10 lies at the core of the touchiness of these plants by breeding a version where this particular stretch-activated chloride ion (Cl^–) channel is absent.

While the mechanical action of the sensor hair triggers the release of calcium ions in both the wild- and knockout dmmsl10 variant, the action potential generation rate was much lower in the latter, while the former continued to generate action potentials even after major stimulation had ceased. This demonstrates that DmMSL10 is essential for the processing of slight stimulation of the sensor hairs and thus prey detection.

A subsequent experiment with some ants being allowed to wander around on the leaves of the wild- and knockout type plants further served to demonstrate the point, with the wild type catching the first ant to waddle onto the leaf, while the knockout type leaf didn’t even twitch as four successive ants failed to propagate the calcium signal sufficiently to close the leaf.

With this knowledge we now have a likely mechanism for how D. muscipula and friends are able to generate the long range calcium signals that ultimately allow them to snack on these tasty protein-and-nitrogen packets on legs. Further research is likely to illuminate how exactly these mechanisms were evolved in parallel with similar mechanisms in animals.

The overall theme of the early part of the Cold War was that of subterfuge — with scientific missions often providing excellent cover for placing missiles right on the USSR’s doorstep. Recently NASA rediscovered Camp Century, while testing a airplane-based synthetic aperture radar instrument (UAVSAR) over Greenland. Although established on the surface in 1959 as a polar research site, and actually producing good science from e.g. ice core samples, beneath this benign surface was the secretive Project Iceworm.

By 1967 the base was forced to be abandoned due to shifting ice caps, which would eventually bury the site under over 30 meters of ice. Before that, the scientists would test out the PM-2A small modular reactor. It not only provided 2 MW of electrical power and heat to the base, but was itself subjected to various experiments. Alongside this public face, Project Iceworm sought to set up a network of mobile nuclear missile launch sites for Minuteman missiles. These would be located below the ice sheet, capable of surviving a first strike scenario by the USSR. A lack of Danish permission, among other complications, led to the project eventually being abandoned.

It was this base that popped up during the NASA scan of the ice bed. Although it was thought that the crushed remains would be safely entombed, it’s estimated that by the year 2100 global warming will have led to the site being exposed again, including the thousands of liters of diesel and tons of hazardous waste that were left behind back in 1967. The positive news here is probably that with this SAR instrument we can keep much better tabs on the condition of the site as the ice cap continues to grind it into a fine paste.

Top image: Camp Century in happier times. (Source: US Army, Wikimedia)

Although the saying of caveat emptor rings loudly in the mind of any purveyor of electronic components, the lure of Very Cheap Stuff is almost impossible to resist. Sure, that $0.60 Ti ADS1115 ADC on LCSC feels like it almost has to be a knock-off since the same part on Digikey is $4 a pop, and that’s when you buy a pack of 1,000. Yet what if it’s a really good knockoff that provides similar performance for a fraction of the price, such as with those cheap ADC boards you can get from Amazon? Cue [James Bowman] letting curiosity getting the better of him and ordering a stash of four boards presumably equipped with at least some kind of cheapo knockoff part, mostly on account of getting all boards for a mere $2.97.

The goal was of course to subject these four purported ADS1115s to some testing and comparison with the listed performance in the Ti datasheet. Telling was that each of the ADCs on the boards showed different characteristics, noticeably with the Data Rate. This is supposed to be ±10% of the nominal, so 7.2 – 8.8 times per second in 8 samples per second mode, but three boards lagged at 6.5 – 7 SPS and the fourth did an astounding 300 SPS, which would give you pretty noisy results.

Using a calibrated 2.5 voltage source the accuracy of the measurements were also validated, which showed them to be too low by 12 mV. The good news was that a linear correction on the MCU can correct for this, but it shows that despite these parts being ADS1115 compatible and having features like the PGA working, you’re definitely getting dinged on performance and accuracy.

[James] said that he’s going to run the same tests on an ADS1115 board obtained from Adafruit, which likely will have the genuine part.  We would also love to see someone test the $0.60 version from LCSC to see whether they can match the datasheet. Either way, if you are eyeing this ADC for your own projects, it pays to consider whether the compromises and potential broken-ness of the knockoffs are worth it over coughing up a bit more cash. As they say, caveat emptor.

There’s no rule that says that logic circuits must always use electrically conductive materials, which is why you can use water, air or even purely mechanical means to implement logic circuits. When it comes to [soiboi soft]’s squishy robots, it thus makes sense to turn the typical semiconductor control circuitry into an air-powered version as much as possible.

We previously featured the soft and squishy salamander robot that [soiboi] created using pneumatic muscles. While rather agile, it still has to drag a whole umbilical of pneumatic tubes along, with one tube per function. Most of the research is on microfluidics, but fortunately air is just a fluid that’s heavily challenged in the density department, allowing the designs to be adapted to create structures like gates and resistors.

Logically, a voltage potential or a pressure differential isn’t so different, and can be used in a similar way. A transistor for example is akin to the vacuum tube, which in British English is called a valve for good reason. Through creative use of a flexible silicone membrane and rigid channels, pulling a vacuum in the ‘gate’ channel allows flow through the other two channels.

Similarly, a ‘resistor’ is simply a narrowing of a channel, thus resisting flow. The main difference compared to the microfluidics versions is everything is a much larger scale. This does make it printable on a standard FDM printer, which is a major benefit.

Quantifying these pneumatic resistors took a bit of work, using a pressure sensor to determine their impact, but after that the first pneumatic logic circuits could be designed. The resistors are useful here as pull-downs, to ensure that any charge (air) is removed, while not impeding activation.

The design, as shown in the top image, is a 5-stage ring oscillator that provides locomotion to a set of five pneumatic muscles. As demonstrated at the end of video, this design allows for the entire walking motion to be powered using a single input of compressed air, not unlike the semiconductor equivalent running off a battery.

While the somewhat bulky nature of pneumatic logic prevents it from implementing very complex logic, using it for implementing something as predictable as a walking pattern as demonstrated seems like an ideal use case. When it comes to making these squishy robots stand-alone, it likely can reduce the overall bulk of the package, not to mention the power usage. We are looking forward to how [soiboi]’s squishy robots develop and integrate these pneumatic circuits.

If there ever was a toy that enjoys universal appeal and recognition, the humble Rubik’s Cube definitely is on the list. Invented in 1974 by sculptor and professor of architecture Ernő Rubik with originally the name of Magic Cube, it features a three-by-three grid of colored surfaces and an internal mechanism which allows for each of these individual sections of each cube face to be moved to any other face. This makes the goal of returning each face to its original single color into a challenge, one which has both intrigued and vexed many generations over the decades. Maybe you’ve seen one?

Although there have been some variations of the basic 3×3 grid cube design over the years, none have been as controversial as the recently introduced WOWCube. Not only does this feature a measly 2×2 grid on each face, each part of the grid is also a display that is intended to be used alongside an internal processor and motion sensors for digital games. After spending many years in development, the Rubik’s WOWCube recently went up for sale at $299, raising many questions about what market it’s really targeting.

Is the WOWCube a ‘real’ Rubik’s Cube, and what makes something into a memorable toy and what into a mere novelty gadget that is forgotten by the next year like a plague of fidget spinners?

The Cube’s Genius

Originally created as a 3D visualization aid for Rubik’s students, the key to the Cube is a sphere. Specifically, the rotation occurs around said internal sphere, with the outer elements interlocked in such a way that they allow for free movement along certain planes. It is this simple design that was turned into a toy by the 1980s, with its popularity surging and never really fading.

There are a few definitions of a ‘toy’, which basically all come down to ‘an object to play with’, meaning something that provides pleasure through act of interacting with it, whether that’s in the innocent sense of a child’s playing time, or the mind-in-gutter adult sense. These objects are thus effectively without real purpose other than to provide entertainment and potentially inflict basic skills on a developing mind.

Although this may seem like a clear-cut distinction, there is a major grey zone, inside of which we find things like of ‘educational toys’ and games like chess. These are toys which are explicitly designed to only provide some kind of reward after a puzzle is solved, often requiring various levels of mental exertion.

It’s hard to argue that a Rubik’s Cube isn’t an educational toy, especially considering its original purpose within the education system. After shuffling the faces of the cube, the goal is to somehow move the individual blocks of color back to their fellow colors on a singular face. This is a process that can be done through a variety of methods, the easiest of which is to recognize the patterns that are formed by the colors.

Generally, solving a Rubik’s Cube is done algorithmically, using visual recognition of patterns and applying the appropriate response. While a casual ‘Cuber’ can solve a standard 3×3 cube in less than half an hour using the basic layer-by-layer algorithm, so-called speedcubers can knock this down to a few seconds by applying far more complicated algorithms. As of May 2025 the world record for fastest single solve stands at 3.05 seconds, achieved by Xuanyi Geng.

In this regard, one can easily put Rubik’s Cube in the same general ‘toy’ category as games like chess, go, and shogi. Although the Cube isn’t by itself a multiplayer game, it also clearly invites competition and a social atmosphere in which to better oneself at the game.

Does It WOW?

With the Cube so firmly established in the global community’s psyche and the multi-colored ‘toy’ a symbol of why paying attention during math classes can absolutely pay off later in life, this brings us to the WOWCube. Looking at the official website for the item, one can’t help but feel less than inspired.

Backing up a bit, the device itself is already a major departure from the Cube. Although the WOWCube’s price tag at $299 is absolutely worthy of a ‘Wow’, the 2×2 configuration is decidedly underwhelming. Yes, it rotates like a Cube, and you could use it like a regular 2×2 Cube if that is your thing and you hate a challenge, but the general vibe is that you’re supposed to be playing the equivalent of Flash or phone games on the screens, in addition to using it like a geometrically-challenged smartphone to display statuses and notifications.

For these applications you have the use of a total of 24 1.4″ IPS LC displays, each with a 240 x 240 resolution. Due to the 2×2 configuration, you have eight blocks that can be moved around, each with its own built-in processor, battery, speaker and 6-axis IMU sensor for gyroscope and accelerometer functionality. These blocks communicate with each other using a magnetic system, and after up to five hours of play time you have to recharge it on the special charger.

Currently you can only pre-order the special Rubik’s WOWCube, with delivery expected ‘by Christmas 2025’. You can however get a good idea of what the experience will be like from videos like the 2022 review video of a pre-production unit by MetalJesusRocks, who also helpfully did a teardown while reconnecting the battery in one block after it disconnected during use.

The internals of a 2022-era WOWCube block. (Credit: MetalJesusRocks, YouTube)

Although this happened with a preproduction unit, it provides some indications regarding the expected lifespan of a WOWCube, as these devices are likely to experience constant mechanical forces being applied to it. With no touchscreen, you have to sometimes rather violently tap the cube or shake it to register user input, which will likely do wonders for long-term reliability.

In the earlier referenced pre-production review, the conclusion was – especially after having a group of random folk try it out – that although definitely an interesting device, it’s too expensive and too confused about who or what it is targeting. This is also the vibe in a brief production unit review by major gadget YouTube channel Mrwhosetheboss, whose ‘Overkill Toys’ video spent a few minutes fiddling with a 2023-era, $599 Black Edition WOWCube before giving it the ‘impressive, but why’ thumbs down.

This also reveals the interesting aspect here, namely that the WOWCube never was designed by the Rubik’s Cube company for Rubik’s Cube users, but rather it’s the Cubios Inc. company that created the WOWCube Entertainment System. The company that owns the Rubik’s brand name, Spin Master, has decided to make this $299 version of with official Rubik’s Cube branding. Basically, you could have bought your own WOWCube all along for the past few years now.

More Of A MehCube

Considering the overwhelming chorus of crickets that greeted the release of earlier versions of the WOWCube Entertainment System, it seems unlikely that slapping Rubik’s Cube branding on a WOWCube will do much to change the outcome. Although Cube enthusiasts don’t mind shelling out a few hundred bucks for a magnetically levitated, fairy dust-lubricated Cube to gain that 0.1 second advantage in competitive solving, this is totally distinct from this WOWCube product.

While absolutely impressive from a technological perspective, and likely a fun toy for (adult) children who can  use it to keep themselves occupied with a range of potentially educational games, the price tag and potentially fragile nature of the device rather sours the deal. You do not want to give the WOWCube to a young child who may drop it harder than a $1,400 iPad, while giving Junior a dodgy $5 Rubik’s Cube clone to develop their algorithmic skills with is far less of a concern.

So if Rubik’s Cube fans don’t seem interested in this device, and the average person might be interested, but only if it was less than $100, it would seem that the WOWCube is condemned to be just another overpriced gadget, and not some kind of ‘digital re-imagining’ of the veritable Cube, as much as the marketing makes you want to sign up for a WOWClub subscription and obligatory ‘AI’ features.