Tech In Plain Sight: Security Envelopes

You probably get a few of these things each week in the mail. And some of them actually do a good job of obscuring the contents inside, even if you hold the envelope up to the light. But have you ever taken the time to appreciate the beauty of security envelope patterns? Yeah, I didn’t think so.

The really interesting thing is just how many different patterns are out there when a dozen or so would probably cover it. But there are so, so many patterns in the world. In my experience, many utilities and higher-end companies create their own security patterns for mailing out statements and the like, so that right there adds up to some unknown abundance.

So, what did people do before security envelopes? When exactly did they come along? And how many patterns are out there? Let’s take a look beneath the flap.

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Deteriorating section of the UCIL plant near Bhopal, India. (Credit: Luca Frediani, Wikimedia)

Cleaning Up Bhopal: The World’s Worst Industrial Disaster

Forty years ago, on the night of Sunday 2 December of 1984, people in the city of Bhopal and surrounding communities were settling in for what seemed like yet another regular night. The worst thing in their near future appeared to be having to go back to school and work the next day. Tragically, many of them would never wake up again, and for many thousands more their lives would forever be changed in the worst ways possible.

During that night, clouds of highly toxic methyl isocyanate (MIC) gas rolled through the streets and into houses, venting from the Bhopal pesticide plant until the leak petered out by 2 AM. Those who still could wake up did so coughing, with tearing eyes and stumbled into the streets to escape the gas cloud without a clear idea of where to go. By sunrise thousands were dead and many more were left severely ill.

Yet the worst was still to come, as the number of casualties kept rising, legal battles and the dodging of responsibility intensified, and the chemical contamination kept seeping into the ground at the crippled plant. Recently there finally seems to be progress in this clean-up with the removal of 337 tons of toxic waste for final disposal, but after four decades of misgivings and neglect, how close is Bhopal really to finally closing the chapter on this horrific disaster?

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One Small Step: All About Stepper Motors

The primary feature of stepper motors is listed right within their name: their ability to ‘step’ forwards and backwards, something which they (ideally) can do perfectly in sync with the input provided to their distinct coils. It’s a feature that allows the connected controller to know the exact position of the stepper motor, without the need for any sensor to provide feedback after a movement, saving a lot of hardware and effort in the process.

Naturally, this is the optimal case, and there are a wide number of different stepper motor configurations in terms of coil count,  types of rotors and internal wiring of the coils, as well as complications such as skipped steps due to mechanical or driver issues. Despite this, in general stepper motors are quite reliable, and extremely versatile. As a result they can be found just about anywhere where accurate, step-based movement is desirable, such as (3D) printers and robotics.

For each application the right type of stepper motor and driving circuit has to be determined, of course, as they also have many reasons why you’d not want to use them, or just a particular type. When diving into a new stepper motor-based project, exactly what are the considerations to pay attention to?

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2024: As The Hardware World Turns

With 2024 now officially in the history books, it’s time to take our traditional look back and reflect on some of the top trends and stories from the past twelve months as viewed from the unique perspective Hackaday affords us. Thanks to the constant stream of tips and updates we receive from the community, we’ve got a better than average view of what’s on the mind of hardware hackers, engineers, and hobbyists.

This symbiotic relationship is something we take great pride in, which is why we also use this time of year to remind the readers just how much we appreciate them. We know it sounds line a line, but we really couldn’t do it without you. So whether you’ve just started reading in 2024 or been with us for years, everyone here at Hackaday thanks you for being part of something special. We’re keenly aware of how fortunate we are to still be running a successful blog in the era of YouTube and TikTok, and that’s all because people like you keep coming back. If you keep reading it, we’ll keep writing it.

So let’s take a trip down memory lane and go over just a handful of the stories that kept us talking in 2024. Did we miss your favorite? Feel free to share with the class in the comments.

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New Years Circuit Challenge: Make This RFID Circuit

A 125kHz PCB antenna, a spiral pattern on a PCB.
The Proxmark3 PCB 125kHz antenna., GNU GPL version 2, GitHub link.

Picture this: It’s the end of the year, and a few hardy souls gather in a hackerspace to enjoy a bit of seasonal food and hang out. Conversation turns to the Flipper Zero, and aspects of its design, and one of the parts we end up talking about is its built-in 125 kHz RFID reader.

It’s a surprisingly complex circuit with a lot of filter components and a mild mystery surrounding the use of a GPIO to pulse the receive side of its detector through a capacitor. One thing led to another as we figured out how it worked, and as part of the jolity we ended up with one member making a simple RFID reader on the bench.

Just a signal generator making a 125 kHz square wave, coupled to a two transistor buffer pumping a tuned circuit. The tuned circuit is the coil scavenged from an old RFID card, and the capacitor is picked for resonance in roughly the right place. We were rewarded with the serial bitstream overlaying the carrier on our ‘scope, and had we added a filter and a comparator we could have resolved it with a microcontroller. My apologies, probably due to a few festive beers I failed to capture a picture of this momentous event. Continue reading “New Years Circuit Challenge: Make This RFID Circuit”

Release Your Inner Ansel Adams With The Shitty Camera Challenge

Social media microblogging has brought us many annoying things, but some of the good things that have come to us through its seductive scrolling are those ad-hoc interest based communities which congregate around a hashtag. There’s one which has entranced me over the past few years which I’d like to share with you; the Shitty Camera Challenge. The premise is simple: take photographs with a shitty camera, and share them online. The promise meanwhile is to free photography from kit acquisition, and instead celebrate the cheap, the awful, the weird, and the wonderful in persuading these photographic nonentities to deliver beautiful pictures.

Where’s The Hack In Taking A Photo?

Of course, we can already hear you asking where the hack is in taking a photo. And you’d be right, because any fool can buy a disposable camera and press the shutter a few times. But from a hardware hacker perspective this exposes the true art of camera hacking, because not all shitty cameras can produce pictures without some work.

The #ShittyCameraChallenge has a list of cameras likely to be considered shitty enough, they include disposables, focus free cameras, instant cameras, and the cheap plastic cameras such as Lomo or Holga. But also on the list are models which use dead film formats, and less capable digital cameras. It’s a very subjective definition, and thus in our field everything from a Game Boy camera or a Raspberry Pi camera module to a home-made medium format camera could be considered shitty. Ans since even the ready-made shitty cameras are usually cheap and unloved second-hand, there’s a whole field of camera repair and hacking that opens up. Finally, here’s a photography competition that’s fairly and squarely on the bench of Hackaday readers. Continue reading “Release Your Inner Ansel Adams With The Shitty Camera Challenge”

Do You Know Vail Code?

Alfred Vail (public domain)

We talk about Morse code, named after its inventor, Samuel Morse. However, maybe we should call it Vail code after Alfred Vail, who may be its real inventor. Haven’t heard of him? You aren’t alone. Yet he was behind the first telegraph key and improved other parts of the fledgling telegraph system.

The story starts in 1837 when Vail visited his old school, New York University, and attended one of Morse’s early telegraph experiments. His family owned Speedwell Ironworks, and he was an experienced machinist. Sensing an opportunity, he arranged with Morse to take a 25% interest in the technology, and in return, Vail would produce the necessary devices at the Ironworks. Vail split his interest with his brother George.

By 1838, a two-mile cable carried a signal from the Speedwell Ironworks. Morse and Vail demonstrated the system to President Van Buren and members of Congress. In 1844, Congress awarded Morse $30,000 to build a line from Washington to Baltimore. That was the same year Morse sent the famous message “What Hath God Wrought?” Who received and responded to that message? Alfred Vail.

The Original Telegraph

Telegraphs were first proposed in the late 1700s, using 26 wires, one for each letter of the alphabet. Later improvements by Wheatstone and Cooke reduced the number of wires to five, but that still wasn’t very practical.

Samuel Morse, an artist by trade, was convinced he could reduce the number of wires to one. By 1832, he had a crude prototype using a homemade battery and a relatively weak Sturgeon electromagnet.

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