Deep-Sleep Problems Lead To Forensic Investigation Of Troublesome Chip

When you buy a chip, how can you be sure you’re getting what you paid for? After all, it’s just a black fleck of plastic with some leads sticking out of it, and a few laser-etched markings on it that attest to what lies within. All of that’s straightforward to fake, of course, and it’s pretty easy to tell if you’ve got a defective chip once you try it out in a circuit.

But what about off-brand chips? Those chips might be functionally similar, but still off-spec in some critical way. That was the case for [Kevin Darrah] which led to his forensic analysis of potentially counterfeit MCU chips. [Kevin] noticed that one of his ATMega328 projects was consuming way too much power in deep sleep mode — about two orders of magnitude too much. The first video below shows his initial investigation and characterization of the problem, including removal of the questionable chip from the dev board it was on and putting it onto a breakout board that should draw less than a microamp in deep sleep. Showing that it drew 100 μA instead sealed the deal — something was up with the chip.

[Kevin] then sent the potentially bogus chip off to a lab for a full forensic analysis, because of course there are companies that do this for a living. The second video below shows the external inspection, which revealed nothing conclusive, followed by an X-ray analysis. That revealed enough weirdness to warrant destructive testing, which showed the sorry truth — the die in the suspect unit was vastly different from the Atmel chip’s die.

It’s hard to say that this chip is a counterfeit; after all, Atmel may have some sort of contract with another foundry to produce MCUs. But it’s clearly an issue to keep in mind when buying bargain-basement chips, especially ones that test functionally almost-sorta in-spec. Caveat emptor.

Counterfeit parts are depressingly common, and are a subject we’ve touched on many times before. If you’d like to know more, start with a guide.

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A Beginner’s Guide To X-Ray Crystallography

In graduate school, I had a seminar course where one of the sections was about X-ray crystallography. I was excited, because being able to discern the three-dimensional structure of macromolecules just by shining X-rays on them seemed like magic to me. And thanks to a lackluster professor, after the section it remained just as much of a mystery.

If only I’d had [Steve Mould] as a teacher back then. His latest video does an outstanding job explaining X-ray crystallography by scaling up the problem considerably, using the longer wavelength of light and a macroscopic target. He begins with a review of diffraction patterns, those alternating light and dark bands of constructive and destructive interference that result when light shines on two closely spaced slits — the famous “Double-Slit Experiment” that showed light behaves both as a particle and as a wave and provided our first glimpse of quantum mechanics. [Steve] then doubled down on the double-slit, placing another pair of slits in the path of the first. This revealed a grid of spots rather than alternating bands, with the angle between axes dependent on the angle of the slit pairs to each other.

 

To complete the demonstration, [Steve] then used diffraction to image the helical tungsten filament of an incandescent light bulb. Shining a laser through the helix resulted in a pattern bearing a striking resemblance to what’s probably the most famous X-ray crystallogram ever: [Rosalind Franklin]’s portrait of DNA. It all makes perfect sense, and it’s easy to see how the process works when scaled down both in terms of the target size and the wavelength of light used to probe it.

Hats off to [Steve] for making something that’s ordinarily complex so easily understandable, and for filling in a long-standing gap in my knowledge.

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This CT Scan Of A PCB Is The Accidental ASMR We Didn’t Know We Needed

At risk of getting any ASMR buffs who might be reading cranky because there’s no audio, [Chris], or [@no1089] on Twitter, has gifted us with this visually stunning scan of his Maxim MAX86160 in-ear heart monitor mounted on a rigidflex PCB. You can take a look, in the video below the break.

If you’re wondering why anyone would scan a board, other than boredom, know that it’s actually quite common. X-Ray machines are commonly used as a quick, passive way to check a board that’s fresh off the production line. These aren’t the X-Rays like those of broken bones you’re (hopefully not too) used to seeing though, they’re Computed Tomography scans (CT scans, CAT scans), in effect just 3D X-Rays.

CT Scan of a BGA

For electronics manufacturers and assemblers, CT scans are incredibly useful because they provide a non-destructive way to check for errors. For example, how do you know if that middle BGA pin is actually soldered correctly? You could run a functional test and make sure everything is working (at least, everything you check), but that takes time. The longer it takes to validate, the higher the manufacturing cost. In manager speak: “cost bad. Fast good.”

It’s also common to use a CT scan to create a full 3D model of a board. This makes it easy to check every little detail, especially the ones that are visually obscured by surface mount devices or critical signal paths that are buried under board layers.

Highlight of solder joints on small-outline integrated circuit (SOIC) to a PCB’s pads.

If you want to geek out on CT scans, you can learn more about the lab that did this scan or by wading into this unclassified research paper from Australia’s Cyber and Electronic Warfare Division.

But we know you really want more of this video, but better. And we’ve got the goods. For the chill folk among you, here’s a 55-minute version without all the CT scan info cluttering the screen. For those of you currently blasting eDM in your headphones, here’s a 30 second clip of it looping at ~5x speed. Eat your heart out:

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It’s NICER In Orbit

Given the sheer volume of science going on as the International Space Station circles above our heads every 90 minutes or so, it would be hard for any one experiment to stand out. ISS expeditions conduct experiments on everything from space medicine to astrophysics and beyond, and the instruments needed to do the science have been slowly accreting over the years. There’s so much stuff up there that almost everywhere you turn there’s a box or pallet stuck down with hook-and-loop fasteners or bolted to some bulkhead, each one of them doing something interesting.

The science on the ISS isn’t contained completely within the hull, of course. The outside of the station fairly bristles with science, with packages nestled in among the solar panels and other infrastructure needed to run the spacecraft. Peering off into space and swiveling around to track targets is an instrument with the friendly name NICER, for “Neutron Star Interior Composition Explorer.” What it does and how it does it is interesting stuff, and what it’s learning about the mysteries of neutron stars could end up having practical uses as humanity pushes out into the solar system and beyond.

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Perovskites: Not Just For Solar Cells Anymore

If you’ve been around long enough, you’ll know there’s a long history of advances in materials science that get blown far out of proportion by both the technical and the popular media. Most of the recent ones seem to center on the chemistry of carbon, particularly graphene and nanotubes. Head back a little in time and superconductors were all the rage, and before that it was advanced ceramics, semiconductors, and synthetic diamonds. There’s always some new miracle material to be breathlessly and endlessly reported on by the media, with hopeful tales of how one or the other will be our salvation from <insert catastrophe du jour here>.

While there’s no denying that each of these materials has led to huge advancements in science, industry, and the quality of life for billions, the development cycle from lab to commercialization is generally a tad slower than the press would have one believe. And so when a new material starts to gain traction in the headlines, as perovskites have recently, we feel like it’s a good opportunity to take a close look, to try to smooth out the ups and downs of the hype curve and manage expectations.

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X-Rays Are The Next Frontier In Space Communications

Hundreds of years from now, the story of humanity’s inevitable spread across the solar system will be a collection of engineering problems solved, some probably in heroic fashion. We’ve already tackled a lot of these problems in our first furtive steps into the wider galaxy. Our engineering solutions have taken humans to the Moon and back, but that’s as far as we’ve been able to send our fragile and precious selves.

While we figure out how to solve the problems keeping us trapped in the Earth-Moon system, we’ve sent fleets of robotic emissaries to do our exploration by proxy, to make the observations we need to frame the next set of engineering problems to be solved. But as we reach further out into the solar system and beyond, our exploration capabilities are increasingly suffering from communications bottlenecks that restrict how much data we can ship back to Earth.

We need to find a way to send vast amounts of data back as quickly as possible using as few resources as possible on both ends of the communications link. Doing so may mean turning away from traditional radio communications and going way, way up the dial and developing practical means for communicating with X-rays.

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Hackaday Podcast Ep 007 – Everything Microcontrollers, Deadly Clock Accuracy, CT X-Rays, Mountains Of E-Waste

Elliot Williams and Mike Szczys look at all that’s happening in hackerdom. This week we dive deep into super-accurate clock chips, SPI and microcontroller trickery, a new (and cheap) part on the microcontroller block, touch-sensitive cloth, and taking a home X-ray to the third dimension. We’re saying our goodbyes to the magnificent A380, looking with skepticism on the V2V tech known as DSRC, and also trying to predict weather with automotive data. And finally, what’s the deal with that growing problem of electronic waste?

Links for all discussed on the show are found below. As always, join in the comments below as we’ll be watching those as we work on next week’s episode!

Direct download (88.7 MB)

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