The Shocking Truth About Transformerless Power Supplies

April 4, 2017 by 114 Comments

Transformerless power supplies are showing up a lot here on Hackaday, especially in inexpensive products where the cost of a transformer would add significantly to the BOM. But transformerless power supplies are a double-edged sword. That title? Not clickbait. Poking around in a transformerless-powered device can turn your oscilloscope into a smoking pile or get you electrocuted if you don’t understand them and take proper safety precautions.

But this isn’t a scare piece. Transformerless designs are great in their proper place, and you’re probably going to encounter one someday because they’re in everything from LED lightbulbs to IoT WiFi switches. We’re going to look at how they work, and how to design and work on them safely, because you never know when you might want to hack on one.

Here’s the punchline: transformerless power supplies are safely useable only in situations where the entire device can be enclosed and nobody can accidentally come in contact with any part of it. That means no physical electrical connections in or out — RF and IR are fair game. And when you work with one, you have to know that any part of the circuit can be at mains voltage. Now read on to see why!

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Canary For USB Ports

April 4, 2017 by 12 Comments

If you’re a paranoid system admin, [errbufferoverfl] has your back with software that keeps track of whenever someone plugs in or disconnects an USB-based device from a workstation.

Christened USB Canary, [errbufferoverfl’s] tool is written in Python. However, even though Python is cross-platform, USB Canary only works on Linux currently. But, fret not: [errbufferoverfl] is already working on Windows and Mac versions.

Primarily, USB Canary watches USB connectors for any activity and logs anything it sees. Moreover, when a USB device is plugged in or unplugged, USB Canary can alert the owner of the workstation via an SMS message courtesy of the Twilio API, post a message in a Slack channel or even make a noise to alert a nearby sysadmin. Additionally, USB Canary can be configured to only run when the workstation is locked (if you’re not completely paranoid).

[errbufferoverfl’s] USB Canary was born out of dissatisfaction with current workstation monitoring tools. You see, most tools only notify users after someone has logged on. [errbufferoverfl] points out that there are means to automate attacks without logging in, and we can think of many unsavory things that can be done when logged out.

While USB Canary won’t protect you from -220V , it might at least warn of a BadUSB attack. But, for the really paranoid, why not try GoodUSB?

[via bleepingcomputer]

How Many Parts In A Triumph Herald Heater?

April 4, 2017 by 67 Comments

This Herald is in much better condition than my 12/50 was. Philafrenzy [CC BY-SA 4.0]
This Herald is in much better condition than my 12/50 was. Philafrenzy [CC BY-SA 4.0]
What was your first car? Mine was a 1965 Triumph Herald 12/50 in conifer green, and to be frank, it was a bit of a dog.

The Triumph Herald is a small saloon car manufactured between about 1959 and 1971. If you are British your grandparents probably had one, though if you are not a Brit you may have never heard of it. Americans may be familiar with the Triumph Spitfire sports car, a derivative on a shortened version of the same platform. It was an odd car even by the standards of British cars of the 1950s and 1960s. Standard Triumph, the manufacturer, had a problem with their pressing plant being owned by a rival, so had to design a car that used pressings of a smaller size that they could do in-house. Thus the Herald was one of the last British mass-produced cars to have a separate chassis, at a time when all other manufacturers had produced moncoques for years.

My 12/50 was the sporty model, it had the high-lift cam from the Spitfire and a full-length Britax sunroof. It was this sunroof that was its downfall, when I had it around a quarter century of rainwater had leaked in and rotted its rear bodywork. This combined with the engine being spectacularly tired and the Solex carburetor having a penchant for flooding the engine with petrol made it more of a pretty thing to look at than a useful piece of transport. But I loved it, tended it, and when it finally died irreparably I broke it for parts. Since then I’ve had four other Heralds of various different varieties, and the current one, a 1960 Herald 948, I’ve owned since the early 1990s. A piece of advice: never buy version 0 of a car.

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How To Find A Twitter Account

April 4, 2017 by 35 Comments

[Ashley Feinberg] is not one to say no to a challenge. When James Comey (the current Director of the Federal Bureau of Investigation for the United States of America) let slip that he has a secret Twitter and Instagram account, [Ashley] knew what she had to do.

At the beginning, [Ashley] knew only a few things: (1) Comey had recently joined twitter and (2) he only allows his “immediate relatives and one daughter’s serious boyfriend” to follow him. As such, [Ashely] deduced that “if we can find the Instagram accounts belonging to James Comey’s family, we can also find James Comey.”

To start, [Ashley] found the Instagram account of Comey’s 22-year-old son, a basketball star at Kenyon College. Not phased by Brien’s locked down Instagram account, [Ashley] requested access to Brien’s account in order to access the “Suggested for You” selections that are algorithmically generated from Brien Comey’s account. Sifting through the provided accounts [Ashley] found one that fit Comey’s profile: locked down with few friends. That account was named reinholdniebuhr. Not sure it was, in fact, James Comey, [Ashley] found Comey’s senior thesis on theologian Reinhold Niebuhr and televangelist Jerry Falwell as verification.

With Comey’s Instagram found, [Ashley] moved back to Twitter (something y’all can’t seem to get enough of). With only seven accounts on Twitter using some variation of “Reinhold Niebuhr” as a user name, [Ashley] was quickly able to narrow it down to one account (@projectexile7) via profiling, sealing the deal on an awesome hack filled quest. Can’t get enough of social media? Don’t worry, you never have to be disconnected.

Hackaday.io User Reviews Six STM32 IDEs

April 4, 2017 by 52 Comments

One of the issues with getting started with any Arm-based project is picking a toolset. Some of us here just use the command line with our favorite editor, but we know that doesn’t suit many people–they want a modern IDE. But which one to choose? User [Wassim] faced this problem, evaluated six different options for STM32 and was kind enough to document his findings over on Hackaday.io.

Many of the tools are Windows-only and at least two of them are not totally free, but it is still a good list with some great observations. Of course, the choice of an IDE is a highly personal thing, but just having a good list is a great start.

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Chess AI, Old School

April 3, 2017 by 8 Comments

People have been interested in chess-playing computers before there were any chess-playing computers. In a 1950 paper, [Claude Shannon] defined two major chess-playing strategies. Apparently, practical chess programs still use the techniques he outlined. If you’ve ever wondered how to make a computer play chess [FreeCodeCamp] has an interesting post that walks you through building a chess engine step-by-step.

The code is in JavaScript, but the approach struck us as old school. However, it is interesting to watch the evolution of code as you go from random moves, to slightly smarter strategy, to deeper searching. Because it is in JavaScript, you can follow along in your browser and find out when the program gets smart enough to beat you. The final version is even on GitHub.

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Stereo Microscope Teardown

April 3, 2017 by 19 Comments

Stereo microscopes are very handy tools, especially for a lot of hackers who now regularly assemble, test and debug SMD circuits using parts as small as grains of sand. We have seen a lot of stereo microscope hacks here at Hackaday, so it helps to take a look inside one to understand how they work. Thanks to [noq2]’s teardown of a Wild Heerbrugg model M8 stereo microscope, we get to do exactly that. His M8 is from the mid-1970s, but it is in mint condition and doesn’t look like it’s over 40 years old. Despite being so old, [noq2] still uses it regularly, so the teardown is not super detailed. But there’s enough for us to get a good idea of how they work.

Stereo microscopes use one of two optical designs — the Common Main Objective (CMO) optical system and the Greenough optical system. [MicroscopeWorld] has a nice blog post explaining these two types and their pros and cons. Not surprisingly, stereo microscopes, just like other optical instruments, are highly modular to allow attaching various extensions, adapters and accessories. The Wild M8 uses the CMO design and its main parts are the binocular head, the main body and the objective lens.

The binocular head consists of the two eyepieces and a pair of prisms that create the binocular split. The alignment of these prisms is critical and they must not be disturbed in their mounting cages. The prism cages have a sliding adjustment to help set the interpupillary distance. The main body contains the zoom and magnification optics and the related mechanics. [noq2] is impressed with the lack of plastics used in the construction of these fine instruments. Finally, there’s the huge objective lens, which [noq2] feels is the Achilles heel of the instrument. Its design is not plan-apochromatic and that causes significant chromatic aberrations, especially when trying to capture photographs. Thankfully, there are other objective lenses which can be used, including some DIY adapter solutions. The Wild Heerbrugg brand was taken over by Leica who still produce a range of stereo microscopes under that badge. If you have one of these microscopes, [noq2] suggests you head over the French forum at lenaturaliste.net where you’ll find extensive information about them.

As a bonus, also check out [noq2]’s ghetto lighting solution for his microscope – a pair of high power LED’s attached to salvaged heatsinks, and mounted on the frame of an old 80 mm cooling fan. The fan frame is perfect since it is the right size to slide over the objective lens. If you’re looking for a more capable lighting solution for your microscope, then check out “AZIZ! Light!”, a microscope ring light with a number of different features.