Miss Beatrice Shilling Saves The Spitfire

January 16, 2018 by 54 Comments

On a bright spring morning in 1940, the Royal Air Force pilot was in the fight of his life. Strapped into his brand new Supermarine Spitfire, he was locked in mortal combat with a Luftwaffe pilot over the English Channel in the opening days of the Battle of Britain. The Spitfire was behind the Messerschmitt and almost within range to unleash a deadly barrage of rounds from the four eight Browning machine guns in the leading edges of the elliptical wings. With the German plane just below the centerline of the gunsight’s crosshairs, the British pilot pushed the Spit’s lollipop stick forward to dive slightly and rake his rounds across the Bf-109. He felt the tug of the harness on his shoulders keeping him in his seat as the nimble fighter pulled a negative-g dive, and he lined up the fatal shot.

But the powerful V-12 Merlin engine sputtered, black smoke trailing along the fuselage as the engine cut out. Without power, the young pilot watched in horror as the three-bladed propeller wound to a stop. With the cold Channel waters looming in his windscreen, there was no time to restart the engine. The pilot bailed out in the nick of time, watching his beautiful plane cartwheel into the water as he floated down to join it, wondering what had just happened.

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You’ll Really Want An “Undo” Button When You Accidentally Send A Ballistic Missile Warning

January 16, 2018 by 91 Comments

Hawaiians started their weekend with quite a fright, waking up Saturday morning to a ballistic missile alert that turned out to be a false alarm. In between the public anger, profuse apologies from officials, and geopolitical commentary, it might be hard to find some information for the more technical-minded. For this audience, The Atlantic has compiled a brief history of infrastructure behind emergency alerts.

As a system intended to announce life-critical information when seconds count, all information on the system is prepared ahead of time for immediate delivery. As a large hodgepodge linking together multiple government IT systems, there’s no surprise it is unwieldy to use. These two aspects collided Saturday morning: there was no prepared “Sorry, false alarm” retraction message so one had to be built from scratch using specialized equipment, uploaded across systems, and broadcast 38 minutes after the initial false alarm. In the context of government bureaucracy, that was really fast and must have required hacking through red tape behind the scenes.

However, a single person’s mistake causing such chaos and requiring that much time to correct is unacceptable. This episode has already prompted a lot of questions whose answers will hopefully improve the alert system for everyone’s benefit. At the very least, a retraction is now part of the list of prepared messages. But we’ve also attracted attention of malicious hackers to this system with obvious problems in design, in implementation, and also has access to emergency broadcast channels. The system needs to be fixed before any more chaotic false alarms – either accidental or malicious – erode its credibility.

We’ve covered both the cold-war era CONELRAD and the more recent Emergency Broadcast System. We’ve also seen Dallas’ tornado siren warning system hacked. They weren’t the first, they won’t be the last.

(Image: Test launch of an unarmed Minuteman III ICBM via US Air Force.)

New Part Day: MEMS Loudspeakers

January 16, 2018 by 47 Comments

MEMS, or Micro ElectroMechanical Systems, are the enabling technology that brings us smartphones, quadcopters, tire pressure monitors, and a million other devices we take for granted today. At its most basic level, MEMS is simply machining away silicon wafers to make not electronic parts, but electromechanical parts. The microphone in your cell phone isn’t an electret mic you would find in an old brick phone from the 80s — it’s a carefully crafted bit of silicon, packed in epoxy, and hanging off a serial bus.

Despite the incredible success of MEMS technology, there is still something in your smartphone that’s built on 19th-century technology. Loudspeakers haven’t changed ever, and the speaker in your newest iThing is still a coil of wire and some sort of cone.

Now there’s finally a MEMS loudspeaker A company called USound has developed the first loudspeaker that isn’t just a bunch of wire and a magnet. This is a speaker built from a silicon wafer that can be as small as 3 mm square, and as thin as 1 mm. Since these speakers are built on silicon, you can also add an amp right onto the package. This is quite literally a speaker on a chip, and we’d bet that there are already engineers at Samsung looking at stuffing this into a flagship phone.

ST and USound announced these extraordinarily small speakers would actually be made, but so far it’s been just that — an announcement. This changed at CES where ST demonstrated VR goggles with multiple MEMS speakers. Does this mean MEMS speakers are on their way to Mouser and Digikey? We eagerly await the product announcement and demo dev board kit.

Raspberry Pi Offers Soulless Work Oversight

January 15, 2018 by 8 Comments

If you’re like us, you spend more time than you care to admit staring at a computer screen. Whether it’s trying to find the right words for a blog post or troubleshooting some code, the end result is the same: an otherwise normally functioning human being is reduced to a slack-jawed zombie. Wouldn’t it be nice to be able to quantify just how much of your life is being wasted basking in the flickering glow of your monitor? Surely that wouldn’t be a crushingly depressing piece of information to have at the end of the week.

With the magic of modern technology, you need wonder no longer. Prolific hacker [dekuNukem] has created the aptly named “facepunch”, which allows you to “punch in” with nothing more than your face. Just sit down in front of your Raspberry Pi’s camera, and the numbers start ticking away. It’s like the little clock in the front of a taxi: except at the end you don’t have to pay anyone, you just have to come to terms with what your life has become. So that’s cool.

It doesn’t take much hardware to play along at home. All you need is a Raspberry Pi and the official camera accessory. Though for the full effect you should add one of the displays supported by the Luma.OLED driver so you can see the minutes and hours ticking away in real-time.

To get the facial recognition going, all you need to do is take a well-lit picture of your face and save it as a 400×400 JPEG. The Python 3 script will take care of the rest: checking the frames from the camera every few seconds to see if your beautiful mug is in the frame, and incrementing the counters accordingly.

Even if you’re not in the market for an Orwellian electronic supervisor, this project is a great example to get you started in the world of facial recognition. With a little luck, you’ll be weaponizing it in no time.

Fooling Speech Recognition With Hidden Voice Commands

January 15, 2018 by 19 Comments

It’s 2018, and while true hoverboards still elude humanity, some future predictions have come true. It’s now possible to talk to computers, and most of the time they might even understand you. Speech recognition is usually achieved through the use of neural networks to process audio, in a way that some suggest mimics the operation of the human brain. However, as it turns out, they can be easily fooled.

The attack begins with an audio sample, generally of a simple spoken phrase, though music can also be used. The desired text that the computer should hear instead is then fed into an algorithm along with the audio sample. This function returns a low value when the output of the speech recognition system matches the desired attack phrase. The input audio file is gradually modified using the mathematics of gradient descent, creating a result that to a human sounds like one thing, and to a machine, something else entirely.

The audio files are available on the site for your own experimental purposes. In a noisy environment with poor audio coupling between speakers and a Google Pixel, results were poor – OK Google only heard the human phrase, not the encoded attack phrase. Given that the sound quality was poor, and the files were generated with a different speech model, this is not entirely surprising. We’d love to hear the results of your experiments in the comments.

It’s all a part of [Nicholas]’s PhD studies around the strengths and pitfalls of neural networks. It highlights the fact that neural networks don’t always work in the way we think they do. Google’s Inception is susceptible to similar attacks with images, as we’ve seen recently.

[Thanks to Wolfgang for the tip!]

3D Printing A Better Quadcopter Frame

January 15, 2018 by 22 Comments

Before you smash the “Post Comment” button with the fury of Zeus himself, we’re going to go ahead and say it: if you want to build a decent quadcopter, buy a commercial frame. They are usually one of the cheaper parts of the build, they’re very light for how strong they are, and replacement parts are easily available. While you could argue the cost of PLA/ABS filament is low enough now that printing it would be cheaper than buying, you aren’t going to be able to make a better quadcopter frame on a 3D printer than what’s available on the commercial market.

The frame features a surprisingly low part count.

Having said that, [Paweł Spychalski] has recently shown off his 3D printed FPV racing quadcopter frame with some surprising results. The frame ended up being surprisingly stiff, and while the weight is a bit high, it’s actually lighter than he expected. If you’re looking to build a quad with the absolute minimum of expense his design might be something to look into.

Of course, [Paweł] is hardly the first person to think about printing a quad frame. But he did give his design some extra consideration to try and overcome some of the shortcomings he noticed in existing 3D printed designs. For one, rather than have four separate arms that mount to a central chassis, his design has arms that go all the way across with a thick support that goes between the motors. The central chassis is also reassuringly thick, adding to the overall stiffness of the frame.

The key here is that [Paweł] printed all the parts with 2 mm thick walls. While that naturally equates to longer print times and greater overall weight, it’s probably more than worth it to make sure the frame doesn’t snap in half the first time it touches the ground.

Beyond the printed parts, all you need to assemble this frame are about a dozen M3 nuts and bolts. Overall, between the hardware and the plastic you’re looking at a total cost of under $5 USD. In the video below [Paweł] puts the frame through its paces doing some acrobatic maneuvers, and it looks like 5 bucks well spent to us.

If you want to go all-in on 3D printed quadcopter parts, you can pair this frame with some printed propellers. Perhaps even a printed camera gimbal while you’re at it. Continue reading “3D Printing A Better Quadcopter Frame” →

Iro3d 3D Prints In Powdered Metal

January 15, 2018 by 25 Comments

Printing with plastic and even resin is getting fairly common. Metal printing, though, is still in the realm of the exotic. A company called Iro3D is aiming to change that with a steel printer that you can buy in beta for about $5000. That seems steep when you can get plastic printers for under $200, but it is sheer bargain basement for something that can print in real metal.

Of course, there’s a catch. The printer doesn’t create a solid metal object right away. What it does is prepares a crucible using sand and metal powder. You then place the crucible in a kiln and what comes out is the final product. You can see a video review of their prototype machine, below from [3D Printing Nerd]. The company’s promotional video that shows a part coming out of the kiln is also below.

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