Solarpunk is all about combining that DIY hacker ethos with sustainability and renewable resources. Our usual PCB manufacturing methods, with their bevy of chemical baths and petrochemical resins aren’t exactly the most sustainable. Digging up some clay and firing it into a circuit board? Very sustainable! And apparently doable, as demonstrated by [Emily Velasco] on Mastadon.
Of course anybody could take a ceramic wafer and call it a circuit board, but that’s only part of what [Emily] did. The ceramic wafer is apparently native clay, which is very cool. Even cooler is that she’s baked the traces into the pottery. While you could conceivably use some sort of conductive glaze for this, what [Emily] did was stamp her desired circuit into the unfired ceramic using a 3D-printed stamp, and then fill the depression with copper powder after the first firing. After that, a second firing is done in a reducing atmosphere to melt/sinter the copper together–it’s not totally clear which is happening here–without burning up.
The results speak for themselves; on the finished demo board, a pair of LEDs blink happily away, driven by the astable oscillator circuit baked right into the clay– and of course the components soldered to it. You’ll have to click through to see it, though.
Given those not-so-sustainable petrochemicals behind our favourite PCBs may be in short supply, this is a timely hack. If it seems familiar, that’s because we featured virtually the same technique last year, but using more-expensive silver powder instead of copper, and a campfire instead of a kiln.
Texas Instruments SA5532A variant of the 5532 op-amp. (Credit: Raimond Spekking, Wikimedia)
First introduced in 1979 by Signetics, the NE5532 was a pretty spiffy dual op-amp for the time with low noise and low distortion. Over the years it has become a standard part that showed up in countless audio products, and has become a so-called jellybean generic component with Texas Instruments (TI) being one of countless manufacturers.
It being such a standard, multi-sourced part makes it thus even more puzzling that TI has now decided to completely overhaul this IC in a way that makes it incompatible with even the original Signetics NE5532. These changes are covered in detail by [Dave] of EEVblog as his mind is pretty much blown at such an incomprehensible change.
The changes entail an entirely different manufacturing process and a big change in specifications, while making no change to the part number. In revision K of the TI datasheet these changes are first seen, with some specifications changed for the better, like a higher unity gain bandwidth by 2 MHz, but a much slower slew rate.
Although the 5532 op-amps are multi-sourced, there are good reasons to just stick with manufacturers like TI, as that means receiving a product change notification (PCN) when anything changes. In the PCN related to this op-amp a change to process node is noted, along with other changes, but no reasoning.
Among the other big changes are a reduction in the supply voltage from 22V to 18V, and a halving of the ESD protection from 2kV to 1kV. Although it might be slightly more efficient on the new process node this way, it clearly comes with a lot of trade-offs that make it an overall worse op-amp, while also being incompatible with the same op-amp from other manufacturers.
In the video [Dave] goes through the datasheets of this jellybean part of other manufacturers, showing that they still have the original 1980s specifications. Only one exception here was the NE5532DR from Shenzhen HuaXuanYang Electronics, whose supply rail voltage is also 18V for some reason, along with a similar internal transistor configuration that reduces the ESD resistance.
In addition to the NE5532 op-amp, it seems that TI also took an ax to the OPA134 op-amp, by removing its offset trim feature and listing the pins as ‘NC’, with a warning to not connect these pins and also worsening other specifications. This makes these similar jellybean parts incompatible, with no change to the part number. Worse is that it continues with the LMH6518, whose changes [Dave] argues might even kill oscilloscopes as they are commonly found in those.
Meanwhile the LM317M also got an overhaul, but here TI opted to give it a new part name, calling it the LM317MQ with at first glance no major degradations in the specifications, but instead some actual improvements. This makes it even more puzzling why TI didn’t give the other ICs a new part number to differentiate them from the jellybean part.
Until there’s some clarification from the side of TI, it might be a good idea to source these jellybean parts from a manufacturer that is not TI, especially when replacing these ICs in older devices.
For those who have never played the hit video games Undertale and Deltarune, the games are partially known for their interesting characters, many of which have eerie, surreal, and expressive designs. One of the more memorable characters from Deltarune is Tenna, a game show host of sorts whose distinguishing feature is an old television as a head, as well as a colorful suit. As a result he’s been the subject of a number of recreations by various cosplayers and makers like [BigRig Creates].
This version of the character was actually inspired by a previous build by [BunnyBii] which used an iPad as the interactive screen/face. Inside the television, though, the actual human found this to be front heavy and limiting in the ways that it could be used interactively, especially since the only way to see the outside world in this version was with a small endoscope and screen. [BigRig Creates]’s version builds on this idea but swaps out the iPad for a Raspberry Pi, allowing for much more customization, and uses a pair of Xreal glasses instead of a screen for the view of the outside world from in the television.
To get the whole costume together, the head is 3D printed with all of the electronics inside, and a game controller integrated into a handheld microphone controls the animations shown on the screen. A vibrant, custom-tailored suit with white gloves rounds out the ensemble, along with a pair of 3D-printed shoe covers since actual yellow shoes were a bit pricy. There were some interesting problems to solve along the way, specifically with regards to power management for all the electronics, but in the end it all seems to have come together quite well. [BigRig Creates] is no stranger to builds with unusual displays, though; one of our favorites was the world’s largest Nintendo 3DS.
Previously, I looked at using the Linux video loopback system from the command line. The basic trick was simple enough: capture video from a real camera, process it with something like ffmpeg, and write the result to a fake camera device via the v4l2loopback device. Then a browser, or any camera-enabled software, sees the fake camera as if it were real. This allows you to manipulate video before sending it to the rest of the world.
That works, and for those of us who like command lines, it’s easy enough to execute. But not everyone loves the command line. In the comments, there was another obvious answer: use OBS Studio.
While OBS is excellent, it is also a bit like using a laser to chop a carrot. If you already use OBS, fine. If you only want to crop a webcam, add an effect, mirror an image, or feed a virtual camera, it can feel like a lot. If you must have a GUI, you can try Webcamoid, which sits somewhere between a simple webcam viewer and a full video production system.
Webcamoid gives you a GUI for selecting a camera, applying effects, and sending the result to a virtual camera. Conceptually, it is much closer to the command-line loopback setup from the previous post than to OBS. You are still building a pipeline from input camera to output camera, but now you can do much of it with buttons and menus instead of shell commands.
That’s in theory, of course. Implementing Webcamoid turned out to be quite the exercise. Granted, this probably varies depending on where you install software. If your distro has a clean working copy of Webcamoid and its dependencies, good for you. For everyone else, keep reading.
Most larger ride-around landscaping machinery has a similar transmission, a transaxle containing a gearbox, or in some cases, a continuously variable drive. [Made In Garage] has a Toro lawn tractor with just such a setup, and when the transaxle failed he replaced it with a hydraulic drive.
The video below is a classic bit of workshop porn, as he fabricates both the hubs and the rear frame to fit a pair of hydraulic motors. The throttle pedal is a hydraulic valve with the lever swapped for a pedal, and the hydraulic reservoir, in a nice touch, is an old fire extinguisher.
We’re not so sure about the pipework in such an exposed position under the machine as we think it would inevitably be damaged, but you can’t argue with the results. Having used a rough service mower with a hydraulic drive in the past, we appreciate always being exactly at the right ratio for the engine.
In the world of buzzwords, the acronym ‘AI’ has absolutely been the buzziest of buzzing buzzwords for at least a few years now. Where previously terms like ‘smart’ and ‘intelligent’ sufficed to promote a product, we are now being told that we are living in an age where this supposedly newfangled ‘artificial intelligence’ is doing literally everything faster and better while also curing cancer on the side. Yet, as a wise man once said: “You keep using that word. I do not think it means what you think it means.”
The obvious implication of using a term like ‘artificial intelligence’ in this manner is that it brings to mind a modern version of early last century’s ‘electronic brain’ vernacular alongside the rise of digital computers. Yet rather than electrons in vacuum tubes and semiconductors propelling us into a brave new world of super-intelligence, we now just use said devices to doom scroll and to engage in passive-aggressive online communications like the typical primate groups in a virtual jungle defending their turf.
Similarly, the term AI is massively oversold today, least of all in the inherent presupposition that we somehow have finally cracked the mystery of the brain and have created an intelligence that can go toe-to-toe with humans and even our corvid dinosaur friends. Perhaps the worst part is that there is a veritable mountain of fascinating algorithms and other constructs that help us automate many tasks today, making it somewhat rude to just give up and call everything ‘AI’ like we learned nothing from the 1980s AI craze.
So what is exactly being smoothed over by the glossy marketing of ‘everything is AI’?
Operating systems are great things to have for general purpose computing, but sometimes they can just get in the way. There’s RAM overhead and processor cycles required for all that operating, after all. For something like a game system, it seems unnecessary. The NES certainly did well enough without an OS, as did its various successors for several console generations.
[Inkbox] wanted to get back to those heady days by programming bare-metal games for a Rasberry Pi 3 that had sat unused since 2016. Games are on cartridge, running bare metal, in assembly — as God and Masayuki Uemura intended. Also, the console is a dodecahedron, because the name GameCube was already taken.
The GitHub link above doesn’t exactly have documentation, at least as of this writing, so you’ll need to watch the video to get the full details. The dodecahedron form factor might not be ideal for packing away in a bag, but as a handheld we have to admit it does look comfortable to hold. Two faces of the dodecahedron get a half-dozen buttons each, which are wired to a GPIO pin on the Pi via a Schmitt trigger for hardware debounce. Like all good consoles, it uses cartridges, these ones being adapted from SD cards on large PCBs derived from a project we featured before.
That all sounds great, but it’s the assembly programming we’re really interested in — skip to around the seven-minute mark in the video for that. Ultimately it’s a build video, so not the ideal tutorial for ARM assembly programming, but it might not be a bad introduction for some. Unfortunately you don’t get line-by-line of the PacMan game he put together — but he does have it in the repository for you to examine. The repo also has STLs if you want to make a dodecahedron of your own.
Of course he’s got a RetroPi cartridge as well, loaded with emulators, and we suspect that’s mostly how this GameDodecahedron will get used. Still, we’ll always have a soft spot for assembly code and projects that use it — be it on ARM, good old 6502, the open-source RISC V architecture, or even the absolute monster of op codes that is x86.
