Machine Learning Helps Electron Microscopy

April 3, 2023 by 8 Comments

Machine learning is supposed to help us do everything these days, so why not electron microscopy? A team from Ireland has done just that and published their results using machine learning to enhance STEM — scanning transmission electron microscopy. The result is important because it targets a very particular use case — low dose STEM.

The problem is that to get high resolutions, you typically need to use high electron doses. However, bombarding a delicate, often biological, subject with high-energy electrons may change what you are looking at and damage the sample. But using reduced electron dosages results in a poor image due to Poisson noise. The new technique learns how to compensate for the noise and produce a better-quality image even at low dosages.

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An Ultra Low Power Dash Cam

April 3, 2023 by 19 Comments

Dash cameras are handy as they provide a video recording of interactions on the road. However, their utility comes from the fact that they are always recording while driving. This always-on means power draw. [Kuzysk] took it upon himself to cut that power draw by a factor of almost 70x.

He found his existing dash cam from MiVue consumed 3.5mA in idle which works out to be a whole amp-hour every 12 days. The custom version takes just 50uA which means it will draw an amp-hour in two years. The brains of the chip are formed by an ATmega328 and an LM2596M, which is a simple step-down regulator. Interestingly, [Kuzysk] purchased clones and original chips and found that the cheaper clones had a lower switching frequency but a much lower power draw. Programming an Arduino bootloader onto the board is fairly straightforward and [Kuzysk] kindly provides his code. It can detect the ACC voltage that’s on when the engine is on and is powered by a permanent 12v connection to the battery.

Overall it’s a straightforward hack that goes through rolling your own Arduino, optimizing for low power, and putting it all together into a polished project. Perhaps for the next version, he can use the ATmega to control a cheaper camera and make it smart.

Thanks to [Microchip makes] and [Abe] for the tip!

Picture of the PCIce card with a fan attached

Server Network Cards Made Extra Cool

April 3, 2023 by 25 Comments

Using cheap and powerful server expansion cards in your desktop builds is a tempting option for many hackers. Of course, they don’t always fit mechanically or work perfectly; for instance, some server-purpose cards are designed for intense amounts of cooling that servers come with, and will overheat inside a relatively calm desktop case. Having encountered such a network card, [Chris] has developed and brought us the PCIce – a PCIe card that’s a holder and a controller for a 80mm fan.

The card gets fan 12V from the PCIe slot, and there’s an ATTiny to control the fan’s speed, letting you cycle through speeds with a single button press and displaying the current speed through LEDs. There’s a great amount of polish put into this card – from making it mechanically feature-complete with all the fancy fasteners, to longevity-oriented firmware that even makes sure to notice if the EEPROM-stored settings ever get corrupted. At the moment, the schematics and the ATTiny firmware are open-source, [Chris] has promised to publish hardware files after polishing them, and has also manufactured a batch of PCIce cards for sale.

When it comes to making use of cheap server-purpose cards, a cooling solution is good to see – we’ve generally seen adapters from proprietary form-factors, like this FlexLOM adapter from [TobleMiner] to make use of cheap high-throughput network cards with slightly differing mechanical dimensions and pinouts. Every batch of decommissioned server cards has some potential with only a slight hitch or two, and it’s reassuring to see hackers make their eBay finds really work for them.

A Compact Camera Running Linux? What’s Not To Like!

April 3, 2023 by 25 Comments

One of the devices swallowed up by the smartphone for the average person is the handheld camera, to the extent that the youngsters are reported to be now rediscovering 20-year-old digital cameras for their retro cool factor. Cameras aren’t completely dead though, as a mirrorless compact or a DSLR should still blow the socks off a phone in competent hands. They’ve been around long enough to be plentiful secondhand, which makes [Georg Lukas]’ look at a ten-year-old range of models from Samsung worth a second look. Why has a deep dive into old cameras caught our eye? These cameras run Linux, in the form of Samsung’s Tizen distribution.

His interest in the range comes from owning one since 2014, and it’s in his earlier series of posts on hacking that camera that we find some of the potential it offers. Aside from the amusement that it runs an unprotected X server, getting to a root shell is fairly straightforward as we covered at the time, and it turns out to be a very hackable device.

Cameras follow a Gartner hype cycle-like curve in the popularity stakes, so for example the must-have bridge cameras and compact cameras of the late-2000s are now second-hand-store bargains. Given that mirrorless cameras such as the Samsung are now fairly long in the tooth, it’s likely that they too will fall into a pit of affordability before too long. One to look out for, perhaps.

Largest Ever Hydrogen Fuel Cell Plane Takes Flight

April 3, 2023 by 72 Comments

In the automotive world, batteries are quickly becoming the energy source of the future. For heavier-duty tasks, though, they simply don’t cut the mustard. Their energy density, being a small fraction of that of liquid fuels, just can’t get the job done. In areas like these, hydrogen holds some promise as a cleaner fuel of the future.

Universal Hydrogen hopes that hydrogen will do for aviation what batteries can’t. The company has been developing flight-ready fuel cells for this exact purpose, and has begun test flights towards that very goal.

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PiEEG Offers Affordable Brain-Computer Interface

April 3, 2023 by 13 Comments

One day in the future, we may interact with our electronic devices not with physical input or even voice commands, but simply by thinking about what we want to do. Such brain–computer interfaces (BCIs), combined with machine learning, could allow us to turn our ideas into reality faster and with less effort than ever before — imagine being able to produce a PCB design simply by thinking about how the completed circuit would work. Of course as an assistive technology, BCIs would be nothing less than life-changing for many.

Today BCIs are in their infancy, but that doesn’t mean there isn’t room for hackers and makers to experiment with the concept. [Ildar Rakhmatulin] has been working on low-cost open source BCIs for years, and with the recent release of his PiEEG on Crowd Supply, thinks he’s finally found an affordable solution that will let individuals experiment with this cutting edge technology.

Implemented as a shield that can be connected to a Raspberry Pi 3 or 4, the PiEEG features 8 channels for connecting wet or dry electrodes that can measure biosignals such as those used in electroencephalography (EEG), electromyography (EMG), and electrocardiography (ECG). With the electrodes connected, reading these biosignals is as easy as running a Python script. While primarily designed for neuroscience experimentation, [Ildar] says the device is also useful for learning more about signal processing, filters, and machine learning.

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Self-Healing Concrete: What Ancient Roman Concrete Can Teach Us

April 3, 2023 by 30 Comments

Concrete is an incredibly useful and versatile building material on which not only today’s societies, but also the ancient Roman Empire was built. To this day Roman concrete structures can be found in mundane locations such as harbors, but also the Pantheon in Rome, which to this day forms the largest unreinforced concrete dome in existence at 43.3 meters diameter, and is in excellent condition despite being being nearly 1,900 years old.

Even as the Roman Empire fell and receded into what became the Byzantine – also known as the Eastern Roman – Empire and the world around these last remnants of Roman architecture changed and changed again, all of these concrete structures remained despite knowledge of how to construct structures like them being lost to the ages. Perhaps the most astounding thing is that even today our concrete isn’t nearly as durable, despite modern inventions such as reinforcing with rebar.

Reverse-engineering ancient Roman concrete has for decades now been the source of intense study and debate, with a recent paper by Linda M. Seymour and colleagues adding an important clue to the puzzle. Could so-called ‘hot mixing’, with pockets of reactive lime clasts inside the cured concrete provide self-healing properties?

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