hardware

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Star Chart Watch Is A Romantic Tragedy

January 10, 2018 by 39 Comments

It’s becoming abundantly clear that [Colin Merkel] doesn’t know the definition of “good enough”. Not only has he recently completed his third (and most impressive) wristwatch build, but he also managed to put together one of the most ridiculously romantic gifts ever conceived. While some of us are giving our significant others a gift card to Starbucks, he made his girlfriend a watch with a chart on the face representing the position of the stars at the time and place of their first meeting.

As per his usual style, the documentation on this build is phenomenal. If paging through his gallery of build images doesn’t make you want to get a lathe and start learning metal working, nothing will. A chunk of stainless steel rod miraculously becomes a gorgeous wrist watch over the course of a few dozen images, perfectly encapsulating that old adage of “making it look easy”.

All you have to do is turn this into that. Easy.

Certainly the highlight of this build is the star chart on the face. To make it, he used PyEphem to plot the position of the brightest stars that were visible at the time and place of their first meeting. He then wrote a script to take those stars and convert their positions to G-Code the CNC could use to drill holes in the appropriate locations. The depth of the hole even corresponds to the magnitude (brightness) of each star, giving the chart a subtle 3D effect.

Unfortunately, [Colin] made a couple of mistakes during this build, to the point that he’s not exactly sure how to proceed. He mentions he might even be forced to start over from scratch. It’s hard to imagine how something that looks this good could ever end up being a failure, but the world of watch making is unkind.

To start with, he used 304 stainless instead of 303. This made machining the case much more difficult, and from his very first cut he realized it was going to be a problem. While it was an annoyance he mentions a couple times during the build log, he was at least was able to work through it.

The real problem came at the end, when he put the watch together. He originally made his designs assuming a front glass which was 0.5 mm thick, but in actuality used a piece that is 0.8 mm thick. This slight difference is just enough to cause the seconds hand to rub up on the glass, putting drag on the movement. The end result is that the battery dies extremely quickly, effectively rendering the watch useless.

We can’t imagine the heartbreak [Colin] felt when he realized what happened; we felt bad just reading about it. But given his track record, we have no doubt he’ll get the issue sorted out. It would be a shame to start over completely, but there’s some consolation in knowing it’s part of the learning process: you don’t become a master of your craft without making a couple mistakes along the way.

The predecessor to this watch was covered here at Hackaday last year, and made quite an impression. It’s interesting to see the improvements made between the two, and we’re certainly excited to see his next build.

Retro Rear-Projection Numeric Display Gets A Teardown

January 7, 2018 by 24 Comments

We recently featured an entertaining project here, a digital clock with a variety of different retro display technologies forming its numerals. Among those was an extremely unusual device, a rear-projection display with an array of bulbs each able to shine through a different letter or numeral slide. There was such interest in this device that its owner [Suedbunker] subjected one to a teardown for all to see.

The displays came from an organ which he suggests may have been manufactured around 1900. We suspect that may be a rather early estimate due to its use of a printed circuit board, but it is no less a fascinating device for it. A rectangular enclosure secured by twist-tabs opens to reveal a matrix of small filament bulbs on a PCB and supported by a stack of resin boards, in front of which was placed a slide with a letter or number for each one. Before that lies a sheet of glass, and then a molded plastic lens assembly which provides an individual lens for each of the 12 bulbs. When a bulb is illuminated with these in place, the letter or number is projected on the screen at the front of the unit.

It has the advantage of simplicity, no need for a high voltage, and high-quality characters and flexibility in displaying alternatives through different slides, though at the expense of quite a bulky package. The bulbs are quite energy-sapping, so for his clock he replaced them with LEDs. We like it as one of the more practical retro numeric displays, but its size means we probably won’t see a comeback.

You can see our write-up of the clock using the projection display here.

Scrap A Hard Drive, Build A Rotary Encoder

January 7, 2018 by 26 Comments

There’s something to be said for the feel of controls. Whether it’s the satisfying snap of a high-quality switch or the buttery touch of the pots on an expensive amplifier, the tactile experience of the controls you interact with says a lot about a device.

[GreatScott!] knows this, and rather than put up with the bump and grind of a cheap rotary encoder, he decided to find an alternative. He ended up exploring hard drive motors as encoders, and while the results aren’t exactly high resolution, he may be onto something. Starting with a teardown of some old HDDs — save those magnets! — [Scott!] found that the motors fell into either the four-lead or three-lead categories. Knowing that HDD motors are brushless DC motors, he reasoned that the four-lead motors had their three windings in Wye configuration with the neutral point brought out to an external connection. A little oscilloscope work showed the expected three-phase output when the motor hub was turned, with the leading and lagging phases changing as the direction of rotation was switched. Hooked to an Arduino, the motor made a workable encoder, later improved by sending each phase through a comparator and using digital inputs rather than using the Nano’s ADCs.

It looks like [GreatScott!]’s current setup only responds to a full rotation of the makeshift encoder, but we’d bet resolution could be improved. Perhaps this previous post on turning BLDC motors into encoders will help.

Continue reading “Scrap A Hard Drive, Build A Rotary Encoder” →

When A Skimmer Isn’t A Skimmer

January 2, 2018 by 163 Comments

I have a confession to make: ever since the first time I read about them online, I’ve been desperate to find an ATM skimmer in the wild. It’s the same kind of morbid curiosity that keeps us from turning away from a car accident, you don’t want to be witness to anyone getting hurt, but there’s still that desire to see the potential for danger up close. While admittedly my interest is largely selfish (I already know on which shelf I would display it), there would still be tangible benefits to the community should an ATM skimmer cross my path. Obviously I would remove it from the machine and prevent others from falling prey to it, and the inevitable teardown would make interesting content for the good readers of Hackaday. It’s a win for everyone, surely fate should be on my side in this quest.

So when my fingers brushed against that unmistakable knobby feel of 3D printed plastic as I went to insert my card at a local ATM, my heart skipped a beat. After all these years, my dream had come true. Nobody should ever be so excited about potentially being a victim of fraud, but there I was, grinning like an idiot in the farmer’s market. Like any hunter I quickly snapped a picture of my quarry for posterity, and then attempted to free it from the host machine.

But things did not go as expected. I spend most of my free time writing blog posts for Hackaday, so it’s safe to say that physical strength is not an attribute I possess in great quantity, but even still it seemed odd I couldn’t get the skimmer detached. I yanked it in every direction, tried to spin it, did everything short of kicking it; but absolutely no movement. In fact, I noticed that when pulling on the skimmer the whole face plate of the ATM bulged out a bit. I realized this thing wasn’t just glued onto the machine, it must have actually been installed inside of it.

I was heartbroken to leave my prize behind, but at the very least I would be able to alert the responsible party. The contact info for the ATM’s owner was written on the machine, so I emailed them the picture as well as all the relevant information in hopes that they could come check the machine out before anyone got ripped off.

Continue reading “When A Skimmer Isn’t A Skimmer” →

34C3: Ultimate Apollo Guidance Computer Talk

December 28, 2017 by 14 Comments

While it might not be as exciting as the Saturn V rocket itself, the Apollo Guidance Computer (AGC) was one of the most important developments of the entire Apollo program. While comically underwhelming compared to modern hardware, the AGC was nothing short of revolutionary when it was developed in the 1960’s. Before the AGC, the smallest computers were about the size of a refrigerator and consumed hundreds of watts; both big problems if you’re trying to pack them into a relatively tiny space capsule with limited resources. Not only did the AGC get humanity to the Moon and back, but it also redefined the state of the art for microcomputers, paving the way for the desktop systems of the 1970’s.

That said, the design and operation of the AGC is downright bizarre to modern eyes; it comes from a time of limitations we can hardly fathom. With this in mind, [Michael Steil] and [Christian Hessmann] put together “The Ultimate Apollo Guidance Computer Talk” for 34C3.

This hour-long presentation walks viewers through every aspect of not only the AGC itself, but how it interacted with the Saturn V rocket and the overall lunar mission. Even if you aren’t enough of a vintage computing aficionado to appreciate the complexities of core rope memory, the presentation gives a fascinating look at the gritty details of one of humanity’s greatest achievements.

Though very slick and easy to understand graphics, [Michael] and [Christian] break down the alien world of the AGC. Even if a lot of this part of the presentation goes over your head, just listen for the sounds of laughter or applause from the audience: that’s when you’re looking at something really off-the-wall.

Of particular note during this presentation is the explanation of how the astronauts actually interacted with the AGC. The AGC’s display and keyboard (referred to as DSKY) may seem rather obtuse even to those who used to hack on a VT100, but [Michael] and [Christian] explain how it’s not quite as complex as it seems. Comparing the input and output of the DSKY with what we would see on a more contemporary command line interface, the presentation makes the case that it’s actually a very straightforward way of talking to the computer.

There’s also a complete breakdown of the different phases of the Apollo mission from launch to landing, explaining what the AGC would be doing at any given time. The DSKY is overlaid on actual footage from the Apollo missions, giving a unique perspective as to what the astronauts would see on their computer during iconic moments such as stage separation or lunar touchdown.

If this presentation has you hungry for more Apollo-era computer technology, we’ve covered plenty of projects to keep you occupied. From building a replica DSKY to leisurely paging through the printed version of the AGC’s source code.

Coasty The Coaster Toaster

December 28, 2017 by 11 Comments

Whether or not you feel the need to laser cut custom drink coasters, you have to be impressed by the amount of thought that went into Coasty.

They say that justice is blind, and while we can’t promise you anything at your next court date, we can at least say with confidence that we’re not the kind of people who will turn down a good hack just because it’s held together with rubber bands and positive vibes. If it works it works, and it doesn’t matter what it looks like. Having said that, we’re blown away by how incredibly finished this particular project is.

Coasty, designed and built by [Bart Dring] is one of those projects that elevate a hack into something that looks like it could be a commercial product. It takes in a common pulpboard coaster and laser cuts any design you want. It’s just the right size, with just the right components because this is Coasty’s purpose. It has a slot to feed in the coaster, and uses this as one of the axes during the laser cutting process, with the laser’s left to right movement as the other. This method makes for a smaller overall footprint and means you never need to open the protective enclosure for normal operation.

One of the most striking elements of Coasty is how much of the hardware is 3D printed. If it isn’t a motor, smooth rod, or other mechanical component, it’s printed. We’re used to seeing 3D printed parts as brackets or mounts, but rarely do you see an entire chassis printed like this. Not only does it take a serious amount of forethought and design, but the print time itself can be quite prohibitive.

But by designing and printing the majority of Coasty, it really gives it a professional look that would have been harder to achieve if it was a bundle of aluminum extrusions.

The back of Coasty features an exposed PCB “motherboard” with a dizzying array of plug-in boards. Hardware like the stepper drivers, Bluetooth radio, and laser power supply are separate modules for ease of maintenance and development. There’s a few neat hardware features integrated into the motherboard as well, like the IR sensor for detecting the edge of the coaster.

The printed filter is an especially nice touch. Containing a scrap of commercially available carbon cloth intended for home air filters, Coasty is able to cut down on the smoke that is invariably produced when blasting cardboard with a 3W 450nm laser.

It turns out that custom drink coasters are serious business for some hackers out there. This isn’t the first time somebody has gone all out to make their mark while simultaneously preventing marks.

Continue reading “Coasty The Coaster Toaster” →

A Guidebook To The World Of Counterfeit Parts

December 27, 2017 by 33 Comments

We’ve all experienced it: that sinking feeling you get when you’ve powered up your latest circuit and nothing happens. Maybe you made a mistake in your design or you shorted something while soldering. It’s even possible that ESD damaged one of your chips. All of these issues and more are possible, maybe even inevitable, when designing your own hardware.

But what if your design is perfect and your soldering skills beyond reproach? What if your shiny new device is DOA but you’ve done everything right? A fascinating report by [Yahya Tawil] makes the case that it’s increasingly possible that you’ve run across a counterfeit component. While it’s still relatively unlikely the hobby hacker is going to get bit by the counterfeit bug, the figures and examples referenced in his report may surprise you.

One of these is an ATmega328, the other is literal garbage.

[Yahya] points to a number of government studies on the rising scourge of counterfeit components, and the numbers are rather surprising. For example, the U.S Department of Commerce conducted a study between 2005 and 2008 where over 50% of respondent manufacturers and distributors had encountered counterfeit components. Another estimate claims that up to 15% of the semiconductors purchased by the Pentagon are counterfeit, presenting a serious risk to national security.

But how exactly does one counterfeit a microcontroller or transistor? Interestingly, in the vast majority of cases, old chips are pulled from recycled circuit boards and new labels are written over the original. Sometimes the forgery is as simple as changing the date code on the component or up-rating its capability (such as labeling it military spec when it isn’t), but in some cases chips with the same package will be labeled as something else entirely. Other tricks are decidedly low-tech: the documentation for the device may list functions and capabilities which it simply does not possess, artificially raising its value.

The report is a worthwhile read, even for those of us who may not be purchasing components in the same quantities as the Pentagon. It may make you think twice before you click “Buy” on that shady site with the prices that seem to good to be true.

Counterfeit components certainly seem to be on the rise from where we’re sitting. We’ve covered a number of other studies on this increasingly common trend, as well as first hand accounts ranging from successful recoveries to frustrating failures.