Having a computer that locks its screen after a few minutes of inactivity is always a good idea from a security standpoint, especially in offices where there is a lot of foot traffic. Even the five- or ten-minute activity timers that are set on most workstations aren’t really perfect solutions. While ideally in these situations we’d all be locking our screens manually when we get up, that doesn’t always happen. The only way to guarantee that this problem is solved is to use something like this automatic workstation locker.
The project is based around the LD2410 presence sensor — a small 24 GHz radar module featuring onboard signal processing which simplifies the detection of objects and motion. [Enzo] paired one of these modules with a Seeed Studio XIAO nRF52840 development board to listen to the radar module and send the screen lock keyboard shortcut to the computer when it detects that the user has walked away from the machine. The only thing that [Enzo] wants to add is a blinking LED to let the user know when the device is about to timeout so that it doesn’t accidentally lock the machine when not needed.
One of the parts of this build that is a little bit glossed over is the fact that plenty of microcontroller platforms can send keystrokes to a computer even if they’re not themselves a USB keyboard. Even the Arduino Uno can do this, so by now this feature is fairly platform-agnostic. Still, you can use this to your advantage if you have the opposite problem from [Enzo] and need your computer to stay logged in no matter what.
In it, we learn that the aforementioned black paint from Ford had so much asphalt in it that black was the only color that would work. Not to go down a This Is Spinal Tap rabbit hole, but there were several kinds of black on those Model Ts. Over 30 of them were used for various purposes. The paints also dried in different ways. While the assembly only took 12 hours, the paint drying time took days, even weeks backing up production and begging for innovation. [edconway] then fast-forwards to an era of “conspicuous consumption and ‘planned obsolescence’” with DuPont’s invention of Duco that brought color to the world of automobiles.
See the article for the real story of advances in paint technology and drying time. Paint application technology has also steadily improved over the years, so we recommend diving in to get the century’s long story.
Members of Pixelbar woke up to shocking news on Wednesday morning this week as they learned that a fire had destroyed the building housing their Rotterdam hackerspace. Pictures of the fire are pretty dramatic and show the entire building ablaze. We’re not familiar with Pixelbar specifically, but most hackerspaces seem to share space with other businesses in repurposed warehouses and other industrial buildings, and it looks like that was the case here. Local coverage doesn’t indicate that a cause has been determined, but they do say that “large batches of wood” were stored in or near the structure, which likely contributed to the dramatic display. There don’t seem to be reports of injuries to civilians or first responders, so that’s a blessing, but Pixelbar seems to have been completely destroyed. If you’re in a position to help, check out their GoFundMe page. As our own Jenny List, who currently lives in The Netherlands, points out, spaces suitable for housing a hackerspace are hard to come by in a city like Rotterdam, which is the busiest port in Europe. That means Pixelbar members will be competing for space with businesses that have far deeper pockets, so anything you can donate will likely go a long way toward rebuilding.
The electronics world has lost a guru. On June 7th this year, Don Lancaster passed away. [Brad] from Tech Time Travellerpaid tribute to Don in a recent video. Don Lancaster was perhaps best known as the designer of the TV Typewriter. The Typewriter drew characters on a TV screen when the user typed on a keyboard. It was the fundamental part of a simple terminal. This was quite an accomplishment in 1973 when the article was first published.
Don embodied the hacker spirit by figuring out low-cost (cheap) ways to overcome obstacles. His genius was his ability to communicate his methods in a way even non-technical people could understand. Keyboards are a great example. Back in the 1970’s a simple keyboard cost hundreds of dollars. Don figured out how to build one from scratch and published an article explaining how to do it.
A research paper titled Biological Organisms as End Effectors explores the oddball approach of giving small animals jobs as grippers at the end of a robotic arm. Researchers show that pill bugs and chitons — small creatures with exoskeletons and reflexive movements — have behaviors making them useful as grippers, with no harm done to the creatures in the process. The prototypes are really just proofs of concept, but it’s a novel idea that does work in at least a simple way.
Pill bugs reflexively close, and in the process can grasp and hold lightweight objects. The release is simply a matter of time; researchers say that after about 115 seconds a held object is released naturally when the pill bug’s shell opens. While better control over release would be good, the tests show basic functionality is present.
Another test involves the chiton, a small mollusk that attaches to things with suction and can act as an underwater end effector in a similar way. Interestingly, a chiton is able to secure itself to wood and cork; materials that typical suction cups do not work on.
A chiton also demonstrates the ability to manipulate a gripped object’s orientation. Chitons seek dark areas, so by shining light researchers could control in which direction the creature attempts to “walk”, which manipulates the held object. A chiton’s grip is strong, but release was less predictable than with pill bugs. It seems chitons release an object more or less when they feel like it.
This concept may remind readers somewhat grimly of grippers made from dead spiders, but researchers emphasize that we have an imperative to not mistreat these living creatures, but to treat them carefully as we temporarily employ them in much the same manner as dog sleds or horses have been used for transportation, or carrier pigeons for messages. Short videos of both pill bug and chiton grippers are embedded below, just under the page break.
[Julio] has an older computer sitting on a desk, and recorded a quick video with it showing how fast this computer can do seemingly simple things, like open default Windows applications including the command prompt and Notepad. Compared to his modern laptop, which seems to struggle with even these basic tasks despite its impressive modern hardware, the antique machine seems like a speed demon. His videos set off a huge debate about why it seems that modern personal computers often appear slower than machines of the past.
After going through plenty of plausible scenarios for what is causing the slowdown, [Julio] seems to settle on a nuanced point regarding abstraction. Plenty of application developers are attempting to minimize the amount of development time for their programs while maximizing the number of platforms they run on, which often involves using a compatibility layer, which abstracts the software away from the hardware and increases the overhead needed to run programs. Things like this are possible thanks to the amount of computing power of modern machines, but not without a slight cost of higher latency. For applications developed natively, the response times would be expected to be quite good, but fewer applications are developed natively now including things that might seem like they otherwise would be. Notepad, for example, is now based on UWP.
While there are plenty of plausible reasons for these slowdowns in apparent speed, it’s likely a combination of many things; death by a thousand cuts. Desktop applications built with a browser compatibility layer, software companies who are reducing their own costs by perhaps not abiding by best programming practices or simply taking advantage of modern computing power to reduce their costs, and of course the fact that modern software often needs more hardware resources to run safely and securely than equivalents from the past.
What do you do, when you move into a shared apartment and find only one socket is available among four electric toothbrushes? Revert to an old-style manual brush? If you’re [luisengineering], not a bit of it. He’s modified an electric toothbrush with the only sensible power plant, a three-horsepower twin cylinder four-stroke gasoline motor. You’ll need to turn on translated subtitles from the original German to watch it, but we hope you’ll agree it’s worth it.
After explaining the problem, the video below the break continues with the assembly of the motor, a model unit available through the usual online suppliers. This alone is interesting, for no doubt many of us have seen these motors for sale and retain some curiosity about them. We expected him to retain the electric drive for the toothbrush and use a generator, but instead, he hooks up the motor via a shaft directly to the input gear. With three horsepower behind the brush, this will surely shift that stubborn plaque! Astoundingly as you can see in the video below the break the contraption works, and both he and a friends perform their dental ablutions with it.
We like the blend of craziness and engineering embodied by this project, and we commend it to you on that basis. If you’re short of electric toothbrush modding ideas, how about an engraving tool?