Reverse Engineering Keeps Keck Telescopes On Track

February 26, 2019 by Dan Maloney 13 Comments

Perched atop a dormant volcano far above the roiling tropical air of the Big Island of Hawai’i sit two of the largest optical telescopes in the world. Each 10-meter main mirror is but a single part of a magnificent machine weighing in at some 400 tons that needs to be positioned with incredible precision. Keeping Keck 1 and Keck 2 in peak operating condition is the job of a team of engineers and scientists, so when the servo amplifiers running the twelve motors that move each scope started to show their age, [Andrew] bit the bullet and rebuilt the obsolete boards from scratch.

The Keck telescopes were built over three decades ago, and many of the parts, including the problematic servo amps, are no longer made. Accumulated wear and tear from constant use and repeated repairs had taken their toll on the boards, from overheated components to lifted solder pads. With only some barely legible schematics of the original amplifiers to go by, [Andrew] reverse engineered new amps. Some substitutions for obsolete components were needed, the PCB design was updated to support SMD parts, and higher-quality components were specified, but the end result is essentially new amplifiers that are plug-in replacements for the original units. This should keep the telescopes on track for decades to come.

Not to sound jealous, but it seems like [Andrew] has a great gig. He’s shared a couple of his Keck adventures before, like the time a failed LED blinded the telescope. He’s also had a few more down-to-earth hacks, like fixing a dodgy LCD monitor and making spooky blinkeneyes for Halloween.

Well-Protected USB Power Strip Makes It Easy To Plug In

February 24, 2019 by Dan Maloney 24 Comments

When we get a new device these days, somewhere in the package is likely to be a wall-wart USB power supply. We look for a place to plug in the little switch-mode dongle, rearrange a few plugs in the mains power strip, and curse its designers for the overly cozy outlet spacing. And all the while that USB-A plug on the power supply cable taunts us with its neat, compact form factor. If only there were a USB power strip.

Unwilling to suffer such indignity any longer, [Scott M. Baker] took matters into his own hands and designed this USB power distribution system. We were surprised to hear that he was unable to find a commercial USB power strip, but even if he had, it likely wouldn’t have had the bells and whistles that he added to his. The circuit went through a couple of revs, but each was focused on protection of the connected USB devices. He included both overcurrent protection, in the form of an electronic fuse built around a TPS2421 hot-swap controller, and overvoltage protection using a crowbar circuit with the usual zener-SCR arrangement. There’s also a transient voltage suppression diode to keep any inductive spikes at bay. Interestingly, each USB outlet has all these protections – it’s not just one protected bus feeding a bunch of USB outlets in parallel, but individual modules with all the circuitry. The modules are gangable and live inside a laser-cut acrylic case. The video below shows the design and build process in some detail.

We have to say that we always learn a lot about circuit design from [Scott]’s projects. You may recall his custom Atari 2600 controller or his dual-port memory retro game console, both interesting and instructive builds in their own right.

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Radiation Detector Eschews Tubes, Uses Photodiode

February 22, 2019 by Dan Maloney 13 Comments

When the topic is radiation detection, thoughts turn naturally to the venerable Geiger-Müller tube. It’s been around for ages, Russian surplus tubes are available for next to nothing, and it’s easy to use. But as a vacuum tube it can be somewhat delicate, and the high voltages needed to run it can be a little on the risky side.

Luckily, there are other ways to see what’s going on in the radioactive world, like this semiconductor radiation detector. [Robert Gawron] built it as a proof-of-concept after having built a few G-M tube detectors before. His solid-state design relies on a reverse-biased photodiode conducting when ionizing radiation hits the P-N junction. The tiny signal is amplified by a pair of low-noise op-amps and output to a BNC connector. The sensor’s analog output is sent to an oscilloscope whose trigger out is connected to a Nucleo board for data acquisition. The Nucleo is in turn connected to a Raspberry Pi for totalizing and logging. It’s a complicated chain, but the sensor appears to work, even detecting alpha emissions from thoriated TIG electrodes, a feat we haven’t been able to replicate with our G-M tube counter.

[Robert]’s solid-state detector might not be optimal, but it has promise. And we have seen PIN diodes used as radiation detectors before, too.

[via Dangerous Prototypes]

Offline E-Paper Typewriter Lets You Write Without Distractions

February 18, 2019 by Dan Maloney 31 Comments

Living and working online is not always easy, especially when it comes to staying focused. All it takes is a moment’s weakness to click on something you shouldn’t and fall down a time-wasting and creativity-killing rabbit hole. Imagine how the creative juices would come to a boil if it were not for the attractive nuisances that lie as close as the next browser tab over.

Creativity-killing online temptations are too much for some to resist, which is why we find this homebrew electronic typewriter so intriguing. Dubbed “SPUDwrite”, or “Single Purpose User Device” by its creator [Lucian], the device is a completely unconnected writing terminal. At its heart, SPUDwrite is just a keyboard attached to an STM32F401 Cortex-M4 microcontroller running MBED and driving an e-paper display. Unfortunately, the refresh rate of the display is too slow to see what you’re typing, so [Lucian] included a small LCD display that shows the current text and where you are in the file. There’s also a thermal receipt printer for those times you just need to hold hardcopy in your hand. [Lucian] introduced the SPUDwrite in an Adafruit show-and-tell session, a clip of which is below the break.

SPUDwrite isn’t perfect, but [Lucian] has plans for version 2, including improving the refresh rate – [Ben Krasnow] might have a few tips on that score. But even as-is, we love the potential for distraction-free creativity while still being able to have an electronic copy of your writing. Our book might finally become a reality with one of these – as long as we can avoid the smartphone.

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This Kerosene Lantern Becomes A Compact Bioreactor

February 15, 2019 by Lewin Day 1 Comment

A bioreactor is a useful thing to have in any biology lab. Fundamentally, it’s a tank in which biological activity can be nurtured and controlled. [The Thought Emporium] needed a visual aid for an upcoming video on bioluminescent bacteria, but figured a single test tube full of the little critters just wasn’t visually striking enough. Thus began the build to turn a kerosene lantern into a full-featured bioreactor.

The ideal bioreactor for the project needed to be visually appealing, biologically safe, and to have the possibility for continuous operation. First, the lantern’s base was sealed with aluminium plate and silicone sealant. The top was then fitted with a plastic plug, which contained passthroughs for air and fluid feeds, UV LEDs for luminescence tests, as well as potential sterilization purposes. Wiring was neatly passed through the arms of the lantern, and an air pump hidden in the top. A battery compartment was also installed so the reactor can be portable, even when fully loaded.

The bioreactor was first filled with highlighter ink, and the UV lights switched on, confirming that the reactor does look the part when filled with glowing fluid. Then, it was flushed with hydrogen peroxide, before being refilled with growth medium and an E. Coli strain which produces a fluorescent red protein. Growth was successful, and there are future plans to use the bioreactor for other projects, too.

It goes without saying that it’s important to take the proper precautions when hacking on biological projects, lest you inadvertently create the zombie virus and take down half the population of the eastern seaboard. Regardless, it’s an impressive build that showcases various techniques for working with biological matter that may not be familiar to the home hacker. If you’re looking for more automation for your home biology hacks, perhaps the OpenLH project may interest you. Video after the break.

[Thanks to Baldpower for the tip!]

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Now Hackaday Looks Great On The Small Screen Too

February 14, 2019 by Mike Szczys 64 Comments

Most of use read and comment on Hackaday from the desktop, while we let our mind work through the perplexing compiler errors, wait for that 3D print to finish, or lay out the next PCB. But more and more people discovering Hackaday for the first time are arriving here on mobile devices, and now they’ll be greeted with a better reading experience — we’ve updated our look for smaller screens.

Yes, it may be a surprise but there are still people who don’t know about Hackaday. But between featuring your amazing hacks, and publishing the incredible original content tirelessly written by our amazing writers and editors, we’re seeing more new readers than ever. Our mission is to bring hardware hacking and the free and open sharing of information and ideas to people everywhere. So we made a responsive design that fits on the tall and narrow shards of glass attached to everyone’s hand.

There’s a generation of mobile-first hackers that we know has been headed our way — just a few years ago I lamented the change this poses to full-sized keyboards. But we think everyone should be interested in the kind of delightful self-learning that happens all the time around here and we’re happy to improve the mobile experience for that reason. Now we look great on a cellphone screen, and continue to look great on your battlestation where you have one-tab-always-open with Hackaday while laying out that circuit board, or debugging those timing issues on a sweet embedded project.

The Future Of Fritzing Is Murky At Best

February 14, 2019 by Brian Benchoff 69 Comments

Fritzing is a very nice Open Source design tool for PCBs, electrical sketches, and schematics for designers and artists to move from a prototype to real hardware. Over the years, we’ve seen fantastic projects built with Fritzing. Fritzing has been the subject of books, lectures, and educational courses, and the impact of Fritzing has been huge. Open up a book on electronics from O’Reilly, and you’ll probably see a schematic or drawing created in Fritzing.

However, and there’s always a however, Fritzing is in trouble. The project is giving every appearance of having died. You can’t register on the site, you can’t update parts, the official site lacks HTTPS, the Twitter account has been inactive for 1,200 days, there have been no blog posts for a year, and the last commit to GitHub was on March 13th. There are problems, but there is hope: [Patrick Franken], one of the developers of Fritzing and the president of the PCB firm Aisler which runs the Fritzing Fab, recently gave a talk at FOSDEM concerning the future of Fritzing. (That’s a direct FTP download, so have fun).

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