If you’ve ever sloshed coffee out of your mug and watched the tiny particles scurry to the edges of the puddle, then you’ve witnessed a genuine mystery of fluid mechanics called the coffee ring effect. The same phenomenon happens with spilled wine, and with functional inks like graphene.
The coffee ring effect makes it difficult to print graphene and similar materials onto silicon wafers, plastics, and other hard surfaces because of this drying problem. There are already a few commercial options that can be used to combat the coffee ring effect, but they’re all polymers and surfactants that negatively affect the electronic properties of graphene.
Some of us are oblivious to how often we touch our faces. The current finding is we reach for our eyes, nose, or mouth every three to four minutes. Twenty times per hour is an awful lot of poking, picking, itching, and prodding when we’re supposed to keep our hands away from glands that can transmit and receive disease. To curb this habit and enter the 2020 Hackaday Prize, [Lloyd lobo] built a proof-of-concept device that sounds the alarm when you reach for your face.
We see an Arduino Uno connected to the classic HC-SR04 ultrasonic distance sensor, an LED, and we have to assume a USB battery pack. [Lloyd] recommends the smaller Nano, we might reach for the postage-stamp models and swap the ultrasonic module out for the much smaller laser time of flight sensor. At its soul, this is an intruder alarm. Instead of keeping siblings out of your room, you will be keeping your hands out of the area below the bill of the hat where the sensor is mounted. If you regularly lift a coffee cup to your lips, it might chastise you, and if you chew sunflower seeds, you might establish a tempo. *crunch* *chip* *beep* *crunch* *chip* *beep*
What is perhaps most interesting though, is that the agencies did the leg work to track the malware to its source: the GRU — Russian intelligence. The name Drovorub translates into “woodcutter” and is apparently the name the GRU uses for the program.
A look inside the code shows it is pretty mundane. There’s a server with a JSON configuration file and a MySQL backend. It looks like any other garden-variety piece of code. To bootstrap the client, a hardcoded configuration allows the program to make contact with the server and then creates a configuration file that the kernel module actively hides. Interestingly, part of the configuration is a UUID that contains the MAC address of the server computer.
The rootkit won’t persist if you have UEFI boot fully enabled (although many Linux computers turn UEFI signing off rather than work through the steps to install an OS with it enabled). The malware is easy to spot if you dump raw information from the network, but the kernel module makes it hard to find on the local machine. It hooks many kernel functions so it can hide processes from both the ps command and the /proc filesystem. Other hooks remove file names from directory listings and also hides sockets. The paper describes how to identify the malware and they are especially interested in detection at scale — that is, if you have 1,000 Linux PCs on a network, how do you find which ones have this infection?
If imitation is the sincerest form of flattery, what then are we to make of something that shares only a few of the original’s design elements, operates in a completely different way, and has been scaled down to a fifth its size? Still seems like flattery to us.
Despite the changes, it’s clear where [Love Hultén] took inspiration for his miniature Marble Machine XS. Readers will no doubt see in it elements from [Martin Molin]’s original Marble Machine, the fantastic plywood and Lego musical contraption, along with his new Marble Machine X, the construction of which never seems to end. Like the originals, [Love]’s miniature version uses a lot of steel balls, albeit considerably scaled down, and it still uses a programming drum to determine where and when to drop them. But rather than strike real traditional instruments, the falling balls strike synthesizer keys, triggering a range of sounds through its built-in speaker. The whole thing is powered by a small electric motor rather than being hand-cranked and is small enough to sit on a desktop, a decided advantage over the mammoth machines to which it pays homage.
We have to say that as much as we love the hacksmanship of the original Marble Machine and the craftsmanship of its successor, the look and feel of [Love]’s machine just blows us away. We’re not sure what materials he used, but the whole hammertone paint scheme and Meccano look is a feast for nostalgic eyes.
Hasselhoff make Larson Scanners famous. That’s the name for the scanning red lights on the front of KITT, the hero car from the popular 1980s TV series Knight Rider. Despite serving a solely aesthetic role, they remain a fun and popular LED project to this day. Putting a new twist on the old concept, [Pete Prodoehl] whipped up a Larson Scanner that you crank to operate.
Built out of LEGO, the project relies on a hand crank to work. The crank turns a drum, onto which is placed several strips of conductive Maker Tape – a steel/nylon material which we’ve looked at before. Strips of tape running side-by-side are bridge by segments of tape on the drum as it turns. The LEDs are switched on in the requisite pattern of a traditional Larson scanner.
The project has inspired further possibilities, such as using similar techniques to produce an electronic music box or player piano that will change tempo as the user changes the speed with the crank. [Pete] notes that turning the crank is an inherently enjoyable experience, and given the wonder inherent in hand-cranked musical projects like Marble Machine X, we can’t wait to see where this one goes next. Video after the break.
Pulling off a flashy project that gets the viral-media hug of widespread approval feels great. Getting there is no easy path to walk and often times the craft that went into a finished project doesn’t even take the back seat but gets no mention at all. Often I find I’m more impressed by — or a least my attention is more strongly captured by — the skills put on display as prominently as the finished build.
Case-in-point this week comes from the model railroad work of [Diorama111]. Seeing an OLED screen in the nose of an HO scale locomotive just like the real-life version is impressive, but how many people missed the one-off soldering masterpiece that went into this one? You’ll marvel at the SMD techniques used with through-hole protoboard on this one.
Occasionally we do get to look over the shoulder of the master as decades of skills are shared for the purpose of passing them on. So was the case back in May when we watched as [Leo] walked through his tips and tricks for prototyping at the electronics bench. This included a lot of non-obvious but clever stuff; tips on working with copper tape for solder buses, using Teflon tubing with bare wire instead of stripping PVC-insulated wire, and a deep dive into copper clad prototyping.
So remember all of us hardware geeks when you look to tell the story of your project. We want to know how it was done at least as much as what was done. There was a time when electronic designers were a separate work group from electronic technicians (and wow, those technicians were in a league of their own). These days we all have that technician hat hanging on our workbenches and I’m always interested in packing in yet another unlearnt skill. Throw us a bone!
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If you are smart, you wouldn’t hand your house key over to a stranger for a few minutes, right? But every time you use your key to unlock your door, you are probably broadcasting everything an attacker needs to make their own copy. Turns out it’s all in the sound of the key going into the lock.
The attack didn’t require special hardware. The team used audio capture from common smartphones. While pushing your phone close to the lock while the victim inserts a key might be problematic, it isn’t hard to imagine a hacked phone or smart doorbell picking up the audio for an attacker. Long-range mikes or hidden bugs are also possible.
There are practical concerns, of course. Some keys have a plateau that causes some clicks to skip, so the algorithm has to deal with that. It sounds like the final result be a small number of key possibilities and not just converge on one single key, but even if you had to carry three or four keys with you to get in, it is still a very viable vulnerability.
The next step is to find a suitable defense. We’ve heard that softening the pins might reduce the click, but we wondered if it would be as well to put something in that deliberately makes loud clicks as you insert the key to mask the softer clicks of the pins.