Year: 2020

Another Blinky Light Project — With A COVID-19 Twist

March 24, 2020 by 3 Comments

It seems all anyone is talking about right now is the virus scare that has most of us with a little extra time on our hands. [Paul Klinger] — a name we’ve seen before — built a blinking LED project to pass the time. So what? Well, the lights are made to look like a SARS-CoV-2 virus and the LEDs blink the virus RNA code. You can see the results in the video below.

This isn’t very surprising when you consider we’ve seen [Paul] make tiny things and even blink out his own DNA, so he’s clearly got some specific interests in this area.

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Wind Farms In The Night: On-Demand Warning Lights Are Coming

March 24, 2020 by 117 Comments

There appears to be no shortage of reasons to hate on wind farms. That’s especially the case if you live close by one, and as studies have shown, their general acceptance indeed grows with their distance. Whatever your favorite flavor of renewable energy might be, that’s at least something it has in common with nuclear or fossil power plants: not in my back yard. The difference is of course that it requires a lot more wind turbines to achieve the same output, therefore affecting a lot more back yards in total — in constantly increasing numbers globally.

Personally, as someone who encounters them occasionally from the distance, I find wind turbines mostly to be an eyesore, particularly in scenic mountainous landscapes. They can add a futuristic vibe to some otherwise boring flatlands. In other words, I can not judge the claims actual residents have on their impact on humans or the environment. So let’s leave opinions and emotions out of it and look at the facts and tech of one issue in particular: light pollution.

This might not be the first issue that comes to mind when thinking about wind farms. But wind turbines are tall enough to require warning lights for air traffic safety, and can be seen for miles, blinking away in the night sky. From a pure efficiency standpoint, this doesn’t seem reasonable, considering how often an aircraft is actually passing by on average. Most of the time, those lights simply blink for nothing, lighting up the countryside. Can we change this?

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Turn By Wire Is A Machinist’s Sixth Sense

March 24, 2020 by 14 Comments

It’s hard not to be a little intimidated by the squeaks and whirs that come with your first journey into a machine shop. Here, skilled machinists pilot giant hunks of cast iron that turn metals into piles of chips to yield beautiful parts. But what if machine tools themselves didn’t have to seem so scary. What if using them could feel a bit more intuitive, even, dare we say, natural from the get-go?

Enter Turn by Wire, a unique set of force feedback and machine control concepts applied to a lathe brought to you by researchers [Rundong Tian], [Vedant Saran], [Mareike Kritzler], [Florian Michahelles], and [Eric Paulos] at Berkelely.

Turn by Wire vastly reimagines the relationship between a user’s control inputs and the machine outputs in two ways: (1) by changing the mapping between the hand cranks and machine movements and (2) by changing the haptic feedback felt by the machinist. Since both of these interactions can be defined programmatically, the researchers created three unique ways of interacting with the lathe. First, by defining a tool path in the graphic user interface (GUI), the machinist can use a single hand crank to step forward and back in time along that toolpath. Second, by applying virtual guidelines in the GUI, both the machine and the hand cranks will physically snap to the guide lines when they are sufficiently close. Finally, the hand cranks can be used to teach the machinist a technique by adding resistive forces into the hand cranks depending on movement while a machinist is stepping through a process like peck drilling.

This is a great example of [Tom Knight’s] “just wrap a computer around it!” as mentioned by [Bunnie Huang] when we featured the IQ Motor Modules. It’s a powerful example of how putting a computer between the controls and the machine can correct for real world imperfections, be they in the mechanics of the machine of the operator. For the curious, have a look at [Rundong’s] paper published at UIST and [Vedant’s] master’s thesis.

 

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Coronavirus Testing: Just The Facts

March 24, 2020 by 42 Comments

The news these days is dominated by the one big story: the COVID-19 pandemic. Since the first reports of infection surfaced in China sometime in late 2019, the novel coronavirus that causes the disease, bloodlessly dubbed SARS-CoV-19, has swept around the globe destroying lives, livelihoods, and economies. Getting a handle on the disease has required drastic actions by governments and sacrifices by citizens as we try to slow the rate of infection

As with all infectious diseases, getting ahead of COVID-19 is a numbers game. To fight the spread of the virus, we need to know who has it, where they are, where they’ve been, and whom they’ve had contact with. If we are unable to gather the information needed to isolate potential carriers, all that we can do is impose mass quarantines and hope for the best. Hence the need for mass COVID-19 testing, and the understandable hue and cry about its slow pace and the limited availability of test kits.

But what exactly do these test kits contain? What makes mass testing so difficult to implement? As we shall see, COVID-19 testing is anything but simple, even if the underlying technology, PCR, is well-understood and readily available. A lot of the bottlenecks are, as usual, bureaucratic, but there are technical limits too. Luckily, there are clever ways around those restrictions, but understanding the basics of COVID-19 testing is the best place to start.

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Breaking Into A Secure Facility: STM32 Flash

March 24, 2020 by 20 Comments

In a perfect world, everything would be open source. Our current world, on the other hand, has a lot of malicious actors and people willing to exploit trade secrets if given the opportunity, so chip manufacturers take a lot of measures to protect their customers’ products’ firmware. These methods aren’t perfect, though, as [zapb] shows while taking a deeper look into an STM microcontroller.

The STM32F0 and F1 chips rely on various methods of protecting their firmware. The F0 has its debug interface permanently switched off, but the F1 still allows users access to this interface. It uses flash memory read-out protection instead, which has its own set of vulnerabilities. By generating exceptions and exploiting the intended functions of the chip during those exceptions, memory values can be read out of the processor despite the memory read-out protection.

This is a very detailed breakdown of this specific attack on theses controllers, but it isn’t “perfect”. It requires physical access to the debug interface, plus [zapb] was only able to extract about 94% of the internal memory. That being said, while it would be in STM’s best interests to fix the issue, it’s not the worst attack we’ve ever seen on a piece of hardware.

Inverse Kinematics Robot Arm Magna-Doodles The Time For You

March 24, 2020 by 8 Comments

Following a surge of creativity fueled by the current lockdown, [Diglo] writes in with his tabletop clock driven by a robotic arm drawing on a Magna Doodle tablet. And if you have one of those still lying around with some old toys and don’t mind cannibalizing it for the project, you too can follow along the source files to build your own.

The clock works by exploiting the principle that Magna Doodle tablets work by being drawn on with a magnetic stylus. That way, to draw on one of them you don’t need to add a point of articulation to bring the pen up and down, [Diglo] simply attached a controllable electromagnet to the end of a two-dimensional SCARA arm. In total, the whole build uses three stepper motors, two to control the movement of the arm, and one on the back of the tablet to sweep a magnetic bar which “erases” it.

This clock is similar to another we’ve featured a few years ago, which also used a Magna Doodle, but greatly improves on the idea. If a Magna Doodle seems too childish to build a magnetic clock however, there’s always ferrofluidic displays to try to dip your fingers into, but we really think you should watch this one in action after the break first.

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Ingenious Hacks That Brought The Original Prince Of Persia To Life

March 23, 2020 by 6 Comments

For many 8-bit computing veterans, the original Prince of Persia game was our first exposure to fluid life-like animation on screen. This groundbreaking technical achievement earned the game’s place in nostalgia and history. Ars Technica invited its original creator [Jordan Mechner] to sit in front of a camera and talk through many technical and game design challenges he had to solve. (Video embedded below. Bonus: correct pronunciation of Karateka directly from the creator’s mouth.)

Enjoy the journey back in time as [Jordan] broke down the convoluted process behind Prince of Persia‘s rotoscope animation. Starting with VCR footage, to film negatives, to tracing out with black markers and white correction fluid to generate a high contrast reference suitable for the (then) state-of-the-art digitizer. But generating those frames was just the beginning! They consumed majority of an Apple II’s memory, thus fighting memory constraints was a persistent headache. Fortunately for us, that limitation also motivated memorable elements such as our “Shadow Man” alter ego.

This Prince of Persia feature is the latest episode of Ars Technica’s “War Stories” series, inviting people behind notable games to talk about their work behind the scenes. The creators of Myst put a lot of effort into minimizing the impact of CD-ROM seek times, an entirely theoretical endeavour as they had no CD burner for verification. The creators of Crash Bandicoot paged in game content from CD in 64kb chunks as a player progressed, allowing creation of levels too large to fit in a PlayStation’s memory all at once. Read over these and other short synopsis of episodes so far or go straight to their YouTube playlist.

If this talk of wrangling bits with 6502 assembly code has whet your appetite for more, the source code for Prince of Persia is available for digging into. Don’t worry if you have long since lost track of your Apple II (or never had one) as the code can run in an emulator.

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