No Assembly Required For This Compliant Mechanism Dial Indicator

July 15, 2020 by 10 Comments

If you’ve ever had the good fortune — or, after a shop mishap, the misfortune — to see the insides of a dial indicator, you’ll know the workings of these shop essentials resemble nothing so much as those of a fine Swiss watch. The pinions, gears, and springs within transmit the slightest movement of the instrument’s plunger to a series of dials, making even the tiniest of differences easy to spot.

Not every useful dial indicator needs to have those mechanical guts, nor even a dial for that matter. This compliant mechanism 3D-printed dial-free indicator is perfect for a lot of simple tasks, including the bed leveling chores that [SunShine] designed it for. Rather than print a bunch of gears and assemble them, [SunShine] chose to print the plunger, a fine set of flexible linkage arms, and a long lever arm to act as a needle. The needle is attached to a flexible fulcrum, which is part of the barrel that houses the plunger. Slight movements of the plunger within the barrel push or pull on the needle, amplifying them into an easily read deflection. When attached to the head of a 3D-printer and scanned over the bed, it’s easy to see even the slightest variation in height and make the corresponding adjustments. Check it out in the video below.

We’re big fans of compliant mechanisms, seeing them in everything from robot arms and legs to thrust vectoring for an RC plane. This might look like something from a cereal box, and it certainly doesn’t have the lasting power of a Starrett or Mitutoyo, but then again it costs essentially nothing, and we like that too.

Continue reading “No Assembly Required For This Compliant Mechanism Dial Indicator” →

Exposing Computer Monitor Side-Channel Vulnerabilities With TempestSDR

July 15, 2020 by 12 Comments

Having been endlessly regaled with tales of side-channel attacks and remote exploits, most of us by now realize that almost every piece of gear leaks data like a sieve. Everything from routers to TVs to the power supplies and cooling fans of computers can be made to give up their secrets. It’s scary stuff, but it also sounds like a heck of a lot of fun, and with an SDR and a little software, you too can get in on the side-channel action.

Coming to us via software-defined radio buff [Tech Minds], the video below gives a quick tour of how to snoop in on what’s being displayed on a monitor for almost no effort or expense. The software that makes it possible is TempestSDR, which was designed specifically for the job. With nothing but an AirSpy Mini and a rubber duck antenna, [Tech Minds] was able to reconstruct a readable black and white image of his screen at a range of a few inches; a better antenna and some fiddling might improve that range to several meters. He also shares a trick for getting TempestSDR set up for all the popular SDRs, including SPRplay, HackRF, and RTL-SDR.

Learning what’s possible with side-channel attacks is the key to avoiding them, so hats off to [Tech Minds] for putting together this simple, easy-to-replicate demo. To learn even more, listen to what [Samy Kamkar] has to say about the subject, or check out where power supplies, cryptocurrency wallets, and mixed-signal microcontrollers are all vulnerable.

Continue reading “Exposing Computer Monitor Side-Channel Vulnerabilities With TempestSDR” →

Printed It: Print-in-Place PCB Gripper

July 15, 2020 by 10 Comments

The goal of Printed It is to showcase creations that truly embrace the possibilities offered by desktop 3D printing. The most obvious examples are designs that can be printed quickly and cheaply enough that they’re a valid alternative to commercially available products. But as previous entries into the series have shown, there are also technical considerations. Is it simply a duplicate of something that could be produced via traditional means, or does the design really benefit from the unique nature of 3D printing?

A perfect example is the Print-in-Place PCB Holder/Gripper created by SunShine. This design is able to hold onto PCBs (or really, whatever you wish) without any additional components. Just pull it off the bed, and put it to work. While having to add a rubber band or generic spring would hardly be an inconvenience, there’s always something to be said for a design that’s truly 100% printable.

The secret is the dual flat spiral springs integrated into the device’s jaws. While most of the common thermoplastics used in desktop 3D printing are relatively stiff, the springs have been designed in such a way that they can be printed in standard PLA. The backside of the jaws have teeth that mesh together, so the energy of the springs is combined to provide a clamping force. Serrations have been added to the jaws to catch the edge of the PCB and help stabilize it.

Visually, it’s certainly striking. The design largely eschews right angles, giving it an almost biological appearance. Many have compared it to the head of a mantis, or perhaps some piece of alien technology.

There’s no question that the design leverages the strengths of 3D printing either; there’s no other way to produce its intricate interlocking components, especially without the use of any sort of fasteners. In short, this design is an ideal candidate for Printed It. But there’s still one question to answer: does it actually work?

Continue reading “Printed It: Print-in-Place PCB Gripper” →

Arduino Plays NES Games

July 15, 2020 by 14 Comments

Watching the advancement of technology is interesting enough by looking at improved specifications for various components as the years go by. But clock speeds, memory size, and power consumption are all fairly intangible compared to actual implementation of modern technology when compared to days of yore. For example, this $40 microcontroller can do what a video game console was able to do in the 80s for a tenth of the (inflation adjusted) price.

The NESDUE is an emulator for NES games which runs completely on an Arduino Due. The Arduino does have some limitations that have to be worked around to get the Nintendo to work, though. For one, it needs to be overclocked to be playable and it also needs a workaround to get past the memory limit of 96 kB of RAM. From there, a small screen is wired up along with a controller (from a Super Nintendo) and the gaming can begin.

This is an impressive feat for an Arduino platform to accomplish, especially with the amount of memory tweaking that has to happen. This might be the most advanced gaming system available that runs everything on an Arduino, right up there with the Arduinocade which can provide an arcade-like experience straight from the Arduino as well.

Continue reading “Arduino Plays NES Games” →

The Many Methods Of Communicating With Submarines

July 15, 2020 by 36 Comments

It sometimes seems hard to believe that we humans have managed to explore so little of what we have so much of: the seas. Oceans cover something like 70 percent of the world’s surface, but we’ve only mapped 20 percent of the ocean floor. The 228,000 ocean-dwelling species that we know about represents about ten percent of the estimated total aquatic species. And almost all the life we know about, and the area that we’ve explored thoroughly, is limited to the first few hundred meters from the surface.

The paucity of our deep-water investigatory efforts has a lot to do with the hostility of the sea to those who haven’t evolved to survive in it. It takes extreme engineering and fantastically expensive machines to live and work even a few meters down, and even then submariners quickly become completely isolated from the rest of the world once they’re down there. Underwater communication is particularly challenging, since the properties of seawater confound efforts to use it as a communications medium.

Challenging though it may be, underwater communication is possible, and in this article we’ll take a look at a few modalities that have made operating under the sea possible, and a new technology that might just extend the Internet below the waves.

Continue reading “The Many Methods Of Communicating With Submarines” →

X-Ray Sleuthing Unveils The Fake In Your Adaptors

July 15, 2020 by 36 Comments

Lets face it, the knock-off variety of our favourite adaptors, cables and accessories are becoming increasingly challenging to spot. We would be the first to admit, to have at some point, been stooped by a carefully crafted counterfeit by failing to spot the tell-tale yet elusive indicators such as the misplaced font face, the strategically misspelled logo or perhaps the less polished than expected plastic moulding and packaging. When you finally come around to using it, if you are lucky the item is still more or less functionally adequate, otherwise by now the inferior performance (if not the initial cost!) would have made it pretty obvious that what you have is infact a counterfeit.

[Oliver] recently found himself in a similar situation, after acquiring a seemingly original Lightning to Headphone Adaptor. Rather than dismay, [Oliver] decided to channel this energy into an excellent forensic investigation to uncover just what exactly made this imitation so deceptive. He began by comparing the packaging, printed typeface and the plastic moulding, all of which gave very little away. [Oliver] concluded that atleast superficially, the clone was rather good and the only way to settle this was to bring out the X-ray, of course!  

The resulting images of the innards make it blatantly obvious as to why the adaptor is indeed very fake. For a start, compared to the original adaptor, the clone hosts a far more thin BOM count! If you are really serious in getting some training to better spot counterfeits, check out a post we featured earlier on the subject!

DIY Dongle Breathes Life Into Broken Ventilators

July 15, 2020 by 51 Comments

We have a new hero in the COVID-19 saga, and it’s some hacker in Poland. Whoever this person is, they are making bootleg dongles that let ventilator refurbishers circumvent lockdown software so they can repair broken ventilators bought from the secondhand market.

The dongle is a DIY copy of one that Medtronic makes, which of course they don’t sell to anyone. It makes a three-way connection between the patient’s monitor, a breath delivery system, and a computer, and lets technicians sync software between two broken machines so they can be Frankensteined into a single working ventilator. The company open-sourced an older model at the end of March, but this was widely viewed as a PR stunt.

This is not just the latest chapter in the right-to-repair saga. What began with locked-down tractors and phones has taken a serious turn as hospitals are filled to capacity with COVID-19 patients, many of whom will die without access to a ventilator. Not only is there a shortage of ventilators, but many of the companies that make them are refusing outside repair techs’ access to manuals and parts.

These companies insist that their own in-house technicians be the only ones who touch the machines, and many are not afraid to admit that they consider the ventilators to be their property long after the sale has been made. The ridiculousness of that aside, they don’t have the manpower to fix all the broken ventilators, and the people don’t have the time to wait on them.

We wish we could share the dongle schematic with our readers, but alas we do not have it. Hopefully it will show up on iFixit soon alongside all the ventilator manuals and schematics that have been compiled and centralized since the pandemic took off. In the meantime, you can take Ventilators 101 from our own [Bob Baddeley], and then find out what kind of engineering goes into them.