Radiation Detector Eschews Tubes, Uses Photodiode

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

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

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

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

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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Tritium Tesseract Makes A Nifty Nightlight

As the cube is to three dimensions, the tesseract is to four. Mortals in this universe find it difficult to contemplate four-dimensional geometry, but there are methods of making projections of such heretical shapes in our own limited world. [Sean Hodgins] was interested in the geometry, and decided to build a tesseract featuring everyone’s favourite isotope of hydrogen, tritium.

The build starts with a 3D printed inner and outer frame, sourced in this case from Shapeways in nylon. Both frames have holes which are designed as a friction fit for off-the-shelf tritium vials. These vials use the radioactive decay of tritium with a phosphor coating to create a dim glow which lasts approximately a decade. With the inner frame held inside the outer with the vials acting as structural supports, the inner and outer surfaces are then fitted with semi-transparent mirrored acrylic, creating a nice infinity effect.

It’s a fun trinket that would be perfect as a MacGuffin in any sci-fi film with a weak plot. [Sean] notes that while the tritium glow is disappointingly dim, the device does make a good nightlight. If you’ve built one and get bored with the hypercube, you can always repurpose your tritium vials into a nuclear battery. Video after the break.

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R/C Whirlygig Is Terrifyingly Unstable

In the days during and immediately after World War II, aerospace research was a forefront consideration for national security. All manner of wild designs were explored as nation states attempted to gain the upper hand in the struggle for survival. The Hiller Hornet was one such craft built during this time – a helicopter which drove the rotor through tip-mounted ramjets. Unsurprisingly, this configuration had plenty of drawbacks which prevented it from ever reaching full production. The team at [FliteTest] had a soft spot for the craft, however, and used it to inspire their latest radio controlled experiment.

Initial experiments consisted of a modified foam wing from a model seaplane, with two left wings facing opposite directions, and joined in the middle. Two motors and props were fitted to the wings to provide rotational motion. After some initial vibration issues were solved, the improvised craft generated barely enough lift to get off the ground. Other problems were faced with centripetal forces tearing the propellers off the wing due to the high rotational speeds involved.

A second attempt started from scratch, with a four wing setup being used, with much higher camber, with the intention to generate more lift with a more aggressive airfoil, allowing rotational speeds to be decreased. The craft was capable of getting off the ground, but instabilities likened to the pendulum rocket fallacy prevented any major gain in altitude.

We’d love to see a redesign to solve some of the issues and allow the craft to sail higher into the air. If you think you know the solution to the whirly bird’s dynamic problems, be sure to let us know in the comments. It should be possible, as we’ve seen successful designs inspired by maple seeds before. Video after the break.

[Thanks to Baldpower for the tip!]

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