Mechanosynthesis Of Atomic Carbon Structures Using Inverted-Mode STM

Generally chemical synthesis involves putting a variety of compounds together in an environment where they will react and self-assemble into the desired product. Direct mechanical manipulation could be significantly more effective with synthesizing various substances. This mechanosynthesis is however not that simple, despite the deceptive appearance of those ball-and-stick representations in high school chemistry class.

This is demonstrated in a recent (pre-publication) study by [Megan Cowie] et al. using inverted-mode STM. One could say that in a sense what we’re trying to accomplish is somewhat akin to what biological cells do in their ribosome, where compounds are synthesized into a protein string using a template. The difference here being that rather than merely trying to create a 2D structure that then folds into a desired shape, we would like to build 3D structures directly.

Using a scanning tunneling microscope (STM) you can measure a surface on a nanoscale, with the inversed principle used in inverted-mode STM (IM-STM) to physically move individual molecules. In the paper the construction of carbon-based 3D structures using IM-STM is demonstrated.

In the paper it is demonstrated how C2 units can be moved using the tip of an IM-STM setup for subsequent polyyne structure construction through C-C bond formation at the target site. Although it’s not quite yet the leap into Neal Stephenson’s The Diamond Age with its science-based matter compilers – i.e. molecular assemblers – it’s definitely another step closer to making advanced feats of nanotechnology a part of every day life.

Radio-Gaga Is A Toddler Friendly Remote In A Radio

Humans of all ages like music, but you can’t exactly pass a toddler the aux cable. That’s not to say the younger set don’t have their own particular tastes– they absolutely do, and they absolutely love to take control and inflict them on the rest of us. [nbr23] has a toddler who loves both music and tactile controls, and decided to combine the two for them with a project he calls Radio-Gaga, which is a gutted Panasonic radio that calls up tunes via Home Assistant.

Interestingly enough the radio is now just a remote control– the speaker has been removed along with the rest of the radio hardware. The buttons and dials are still there, though, letting the toddler control what tunes are on offer and at what volume via couple of potentiometers hooked to an ESP32. The sound itself is being served up from the homelab to a USB speaker. There’s one notable flaw with this architecture: if the batteries die on the remote, “Let it Go” does not until an adult intervenes manually or recharges the remote.

One interesting lesson [nbr23] wanted to share was that he was able to improve an unsatisfactorily slow startup time by assigning the device a static IP on his network– apparently the single longest step in getting the tunes going was negotiating a DHCP lease. Skipping that gets the tunes playing in under a second, which is fast enough even for the most impatient of tiny humans.

If you prefer a more self-contained device, we’ve seen toddler jukeboxes that keep storage and speaker built-in, many with NFC control. 

Overpowered RC Car + Gimbal Cam = The Greatest Chase Vehicle We’ve Ever Seen

Modern cinema relies very heavily on quadrotor drones, because they make for very smooth, very easy to position platforms. From slow pans to chase shots, drones are great– if your shots can be taken at a high enough altitude. Close to the ground, things get a bit dodgier. That’s where [Transistor Man]’s camera chase vehicle comes in— it’s a rover, so it excels close to the ground. In fact, it can’t go anywhere else, except perhaps if provided with a jump. It’s got a hefty gimbal to hold the camera steady on any terrain, a decade-old surplus radio to provide full HD FPV to the remote driver, and a powerful 1/5th scale radio control rally chassis to make it all go. Plus googly eyes, because everything is better with googly eyes.

It looks like an enormous amount of fun to drive, but more importantly it provides smooth, cinematic shots from the professional Sony camera held in the gimbal. One big takeaway is that when 3D printing something that will bounce around this much, you can’t rely on pure strength– flexible filaments are your friend. Just about everything printed ended up remade in TPU if it didn’t start that way. The other takeaway is that we’ve reached enough of a technological plateau that if you scrounge around, you can build something to take a top-of-the-line footage with decade-old castoffs, like the gimbal and radio used in this project, which is a great thing for hobbyists and small studios.

If you can’t find surplus, you could always DIY a gimbal. We’re not filmmakers, but we find ourselves wondering how shots made with this rover would compare to a camera slider.

Reviving Mystery Nintendo 64 Game Cartridge Found In The Woods

As far as things go that you are likely to find during a relaxing walk in the forest, Nintendo 64 game cartridges probably do not rank high on that list. Yet this is what happened to a friend of [BlueBox Tinkers] a few years back, leaving him dying to see whether the cartridge would still work, as well as what game it is since its labels got obliterated courtesy of its time spent enjoying the outdoors. Fortunately he recently got a chance to see whether he could revive this cartridge.

The insides look pretty much like what you’d expect after presumably months or years of exposure, with the metal shield severely corroded. The PCB does however look pretty decent still, with obvious signs of corrosion on the front-side vias, and a pretty gross-looking back side.

Unfortunately it wasn’t confirmed whether this friend tried to stick this old cartridge into an N64 console, but [BlueBox Tinkers] wasn’t going to take any such chances. First up was an inspection and deep cleaning of the PCB, showing that it had escaped real damage, with the shield having taken the brunt of the corrosion. Cleaning up the shield and the insides of the plastic shell is by far the hardest part, with the pitted metal and rust stuck on the plastic. For a full restoration you’d probably want to for a reproduction shell and shield here.

Ultimately the game turned out to still work, with the mystery game sadly fairly predictable, but with someone’s old save files still intact. Somehow it seems that what Nintendo did to make N64 cartridges dust- and child-resistant also makes it survive in the woods, so if you find one during a forest walk, it’s totally worth it to adopt it and take it home.

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Get A Handle On This Compact Pi Portable

Between the speed and reliability of modern desktop 3D printers and the abundance of powerful single-board computers, there’s never been a better time to build a personal computing device that bucks traditional forms for something more bespoke. Whether you want to go all in on Gibsonian cyberdeck aesthetic or a distraction-free writing device to take notes on, there’s no shortage of examples out there that you can turn to for inspiration.

A recent entry into the field, the Don’t Panic Cyberdeck from [Paul Rickards], is a particularly approachable specimen for those looking to experiment with alternative computing experiences. While the final product certainly stands out among the throngs of nearly identical laptops, it doesn’t take a huge investment in time or money to put one of your own together.

Which is not to say the project is simplistic, exactly. Rather, as [Paul] released the design under the Creative Commons license and was kind enough to provide not only a detailed Bill of Materials but assembly instructions, the community is able to benefit from the sleepless nights he no doubt put into it.

In it’s baseline configuration, the Don’t Panic uses a Raspberry Pi 3A+, a Pimoroni HyperPixel 4.0 Square LCD (touch optional), and a Rii 518BT keyboard. Those core components would be enough to get you up and running, but if you want battery power you’ll also need to add a LX-2BUPS UPS board and a pair of 18650 cells. Audio might be nice as well, and for that [Paul] recommends a PAM8403 breakout board. He’s even got a printable volume knob that slips over the board’s potentiometer and peeks outside the case.

Of course, the best cyberdeck builds are customized to meet their owner’s specific needs, so your loadout doesn’t need to match [Paul]’s exactly. Except the handle, anyway. That feature is non-negotiable. Mainstream computers have far too few handles for our liking.

A Brief History Of The Crazy Old 7-Segment Display

How old is the seven-segment display? Surely it is a product of the 1970s. After all, calculators started showing up, and the height of junior high humor was plugging 7734 into your calculator and showing it to someone upside down. Of course, for it to go mainstream, maybe they really originated in the 1960s, but no earlier than that, right? Actually, no. Sure, the LED seven-segment display had to wait for LEDs. But the actual idea is much older than that.

The concept of building numbers from a small set of reusable segments predates LED displays by decades. In fact, the basic idea appears in patents from the early 1900s and may have roots in even older mechanical signs and printing techniques.

The history isn’t entirely straightforward. Unlike vacuum tubes or transistors, segmented displays evolved gradually through a series of practical ideas rather than one defining invention.

Blacking out the Eight

While looking into the history of segmented displays, I was reminded of something I’d seen years ago in retail stores: reusable price tags printed with rows of eights.

Rather than printing every possible price, the clerk simply used a marker to black out portions of each figure, transforming an 8 into whatever digit was needed. Cover a few strokes, and the eight becomes a three. Remove a different set, and it becomes a zero or a five. It was, in essence, a manual segmented display.

Finding the exact origin of these price tags is akin to finding out where Romans bought sponges. They were inexpensive commercial supplies, not the sort of products that historians carefully documented. My recollection is from the middle of the twentieth century, but the underlying concept is almost certainly older.

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Fixing A Dodgy Cheap Audio DAC

One of the attractions of buying at the bottom end of the electronics market by mail order from China is that you never quite know what will come your way. Sometimes it’s a diamond in the rough, while with others it’s a mess. Occasionally along comes something which should work but doesn’t, and that’s the moment when you wonder if you could fix it. [Nyanpasu64] had just such a device, an HDMI to VGA converter with audio that didn’t work. What could be wrong?

The HDMI to VGA chip has an onboard audio digital-to-analog converter (DAC), and it’s a delta-sigma design. This type of DAC is frequently used in audio applications because it works by shifting its switching frequency many times higher than the input sample rate, thus reducing considerably the distortion. This one wasn’t performing as advertised though, and the problem turned out to be that switching frequency being all over the output. Clearly the filter wasn’t working, which led to the design of a new filter. The write-up is therefore an extensive dive into filter design, and in part also a discovery of the effect of impedance on them.

For a super-cheap module to cause so much work, one might ask why not simply spend a few more dollars and get a better one. But had they done that we wouldn’t have seen this write-up, so we’re sticking with team cheap.

We’ve looked at audio DACs, in the past.