TechyMagThings

We’ve seen the GeekMagic SmallTV line of devices before — these cheap gadgets combine a microcontroller and a display in a little plastic case that can be used to show the time or weather. Powered by either an ESP8266 or an ESP32, the things could easily pass for a hobby build if it wasn’t for their professionally produced enclosures. In fact, we wouldn’t be surprised if GeekMagic lifted the idea from an existing DIY project.

As you might expect we’ve seen several hacks for these devices already, which usually involves replacing the stock firmware. But this latest approach is unique in that you don’t need to mess with the stock software, nor do you need to break out the soldering iron. By leveraging a built-in photo viewer function of the SmallTV [Yongha Kim] shows how you can get the gadget to display pretty much whatever you want.

The trick here is that the image is being generated by a machine on the network, say your desktop or server, and being pushed over to the SmallTV over HTTP. In this example the image is being generated in Python with the Pillow library, and [Yongha] has it showing Claude and Codex usage data, but you could really approach this however you wish.

All you need to do is create a 240×240 image and shoot it over to the device, so you’re free to come up with whatever sort of visuals you’d like. It even supports GIF if you’d like to work animation into it. The content can of course be whatever information you’re interested in showing, and it can be generated by whatever programming language or tool you’re most comfortable with. It’s a fascinating proof of concept, and now that the method has been demonstrated we’re interested to see where the community can take it.

If this all sounds a little too easy for your tastes, don’t worry. There’s a plenty deep rabbit hole you can dive into should you elect to replace the device’s firmware entirely.

One of the problems with planetary science is that you generally cannot easily investigate the exact conditions in their interior, so you’re left to extrapolate what is happening inside them based on surface scans. One of the resulting questions is what ice giants like Neptune and Uranus in Earth’s solar system have exactly at their core. We do know that it is mostly rocks and ice, but what kind of ice you end up with at these intense pressures is a good question that [Alexis Forestier] et al. set out to answer, with their results published in a Physical Review Letter paper (ArXiv preprint).

It’s noteworthy that there isn’t just water ice at these planetary cores, with this study only investigating water ice specifically. In order to get the water to the pressures it would experience courtesy of ice giant gravity, a diamond anvil was used, with synchrotron x-ray diffraction allowing for the changes to the sample to be observed.

The phase diagram of water includes a number of phases beyond what us Earth-dwellers would call ‘ice’, with at higher pressures above about 80 GPa the formation of ice X, featuring a body-centered cubic (BCC) oxygen sublattice. Subsequent discovered phases were face-centered cubic (FCC) and now hexagonal close-packed (HCP) ice, all differing in the packing of the oxygen sublattice.

In addition to extreme pressures, temperatures also had to be increased by using the laser heating feature of the diamond anvil. At around 2,000K and over 200 GPa the HCP phase was found, with a mixed FCC-HCP phase at intermediate pressures.

Although not immediately providing answers to questions pertaining to the aforementioned ice giants, it gives planetary scientists yet another clue that they can use in future investigations, as well as provide more insight into this most fascinating phase of water that’s actually its own little galaxy of phases.

There are some projects that seem at first sight to be easy, but anyone who tries them finds a whole heap of unexpected problems and turns to the off-the-shelf device. PCB antennas for example, or data links using LEDs, whether IR or visible. The latter doesn’t faze [Luca Soltoggio] though, because he has two ESP32s talking to each other using visible light. Best of all, both use a single LED as both transmitter and receiver.

The software is called SecurePair, and is an Arduino library for exchanging keys and communicating with encryption. The LEDs are the cool hardware hack but it’s designed to work with ESPNow or LoRa too, indeed a typical use case would see light for pairing and wireless for the exchange of encrypted data.. In case you were wondering, it relies on the property of an LED that it’s also a photodiode of sorts. Best of all, while the examples have two ESP32s, it’s not limited to that number and many more can join the conversation if needed.

Check out the video below to see it in action — if you’re curious about LEDs as sensors, we’ve been there too.

With the rise of synthetic polymers in everywhere from clothing, packaging and beyond, we have also seen a corresponding rise in fragments of these polymers in the environment. These micro- and nanoplastics (MNPs) come in a wide variety of sizes, but have in common that they do not break down very easily, leaving filtration as an important way to keep them out of our potable water sources. A recent paper by [Ethan A. Crawford] et al. in  Separation and Purification Technology details a way to use a low-cost, 3D-printed filtration mesh to filter out up to 90% of MNPs using their prototype.

This prototype uses a multi-layer filtration system printed in PLA, creating a flow-through system in which polyethylene glycol (PEG) acts as a sacrificial additive to the PLA. Whereas creating the fine pores required for filtration of MNPs is impossible using FDM printing, the spheres of PEG that form inside the printed filter can be subsequently etched away using nothing but hot (80°C) water, leaving behind a porous surface capable of trapping fine particles.

These pores are characterized in the paper, with the PLA-PEG10 sample showing the best porous structure while maintaining structural integrity of the PLA material. With 20 layers of these filters a filtration efficiency of 90% was achieved, though as the authors note aspects like improving the system and potential reusability still have to be investigated.

We have previously looked at MNPs, including how little we know about how many of them really are inside our bodies right now, and how lab gloves may be contaminating test results.

Building anything that flies from scratch is an ambitious undertaking, even if it’s ‘just’ radio-controlled. 3D printing the aircraft isn’t that odd these days, but putting a hot jet engine into a plastic airframe is another ambitous reach. Getting said 3D printed airframe up to the transonic speed of Mach 0.8? Ambition, thy name is Kingchaser. Or at least, that’s the name [The Mach Initiative] give to their very ambitious aircraft, the video about which is embedded below.

The airframe is largely 3D printed from PETG– that’s all the orange bits– but there are carbon fiber rods and an aluminum frame to help take up the strain. The black section around the motor is printed from PPS-CF– that’s Polyphenylene sulfide with carbon fibre–wrapped in carbon fiber to take the heat. This all builds off a smaller PLA version that’s already flown called Kingfisher, which claimed the title of the first 3D printed jet. That flight is on their YouTube channel, if you’re interested.

Now with a bigger aircraft and a much bigger engine– 300 N or 68 lbf of thrust– they’re going for the speed record. If they get even close to the design goal of mach 0.8, they’re absolutely going to leave the world’s fastest drone– a 626 km/h quadcopter we’ve written about— in the dust.

The switch to PETG from PLA, for the record, was to deal with the expected aerodynamic heating at that speed, about 990 km/h or 615 mph. An interesting detail many don’t bother with when it comes to 3D printed airplanes is that the skin has all been polished smooth, since skin drag is dominant at that speed regime. The video is just chock full of those little details that it takes to defeat drag and get to the record speed, and there’s more to come from [The Mach Initiative].

Speaking of remote controlled speed records, we covered another batch of brits take home the land speed record a few years back. May [The Mach Initiative] see such success!

Copper sulfate crystals are probably among one of the prettiest crystals you can grow at home, with even just a simple setup with some copper scrap and vinegar already capable of producing lots of them. Yet what if you want to grow really big ones? In that case the [Crystalverse] has got your back, with a recent video that expands on an older blog post.

In lieu of the copper-and-vinegar approach you can also obtain copper sulfate directly, since it’s a common fungicide, rootkiller as well as drying agent. This means that your local brick-and-mortar retailer or favorite online store probably has a few kg of the stuff available for sale.

As with most large crystal growing procedures the key is to have a saturated solution, which for copper sulfate just takes near-boiling water, to create a mesmerizingly blue liquid if there are no contaminants in it. By adding slightly more copper sulfate there are also crystallization sites on the bottom of the jar to draw these away from your large crystal.

From there it’s the same as with growing other large crystals – even those from sugar – with a seed crystal suspended into the solution, along with a silent prayer to the crystal gods that said seed crystal continues to grow without any defects. One gotcha with copper sulfate crystals is that the intense blue color is largely due to the presence of water molecules. This means that once it dehydrates, it turns effectively white.

Also of note that is the slower the crystal grows, the better the result is likely to be. During the months that it takes for these large crystals to grow, you need to carefully manage the copper sulfate solution, remove competing crystals on the bottom of the container and keep the temperature as constant as possible.

Back in the old days the IBM-PC, like most of its contemporary computers, shipped with BASIC in ROM. Even after it stopped living in ROM, IBM-Compatibles shipped with GW-BASIC, and now we have a project that asks: what if they still did? Thoreau BASIC is GW-BASIC, but updated for the 21st century.

It’s meant to be code-compatible with all old GW-BASIC code — which means, yes, line numbers and GOTOs abound — but it can boot from a modern x86 PC’s UEFI or run under Windows and take full advantage of modern hardware with 64-bit memory and multithreading support. Graphics are 24-bit at any resolution your monitor can handle, and there are a number of handy built-in commands to handle file management, graphics — including sprites — mouse and keyboard input, 32-channel sound, and more. It is also not strictly an interpreted language. Programs can be compiled to run under Windows or bare-metal on UEFI x86 machines.

It’s not open source, but the project is “pay what you want” over on Itch.io, where you can also see a number of examples.

We’ve seen other attempts to revive BASIC over the years, like MoonBASIC or BASIC-256, but we have to admit it’s never going to be the dominant force it once was, regardless of how nostalgic we might get. That’s probably for the best, but it’s still nice to know you can boot to BASIC if you really, really want to. Do you think it would work with our preprocessor?