Month: April 2017

Interactive Board Prompts Moves For Checkers And Chess

April 16, 2017 by 6 Comments

In terms of equipment, chess and checkers are simple games — just a handful of pieces and a checkered gameboard. The simplicity belies the underlying complexity of the games, though, and goes a long way toward explaining their popularity over the millennia.

Increasing the complexity with an interactive game board for chess and checkers might seem counterintuitive, then. But [Bogdan Berg]’s project aims to not only teach checkers and chess but to make games a little more exciting and engaging. Looking a little like a tabletop version of the interactive dance floors we’ve been seeing a lot of lately, the board is built from laser-cut acrylic with plywood dividers to isolate all 64 squares. Neopixels and Hall-effect sensors are mounted to custom PCBs that stretch the length of a row and are wired to an Arduino Mega with lots of IO. Game pieces are colorful fridge magnets. [Bogdan]’s current program supports checkers and keeps track of where the pieces have been moved relative to their starting position and prompts users with possible legal moves.

[Bogdan]’s board already looks like a lot of fun in the video below, and we like the quality of the build and the unobtrusive nature of the interactivity. When he gets around to implementing chess, though, he might want something fancier than fridge magnets for game pieces.

Continue reading “Interactive Board Prompts Moves For Checkers And Chess” →

Hacker U.

April 16, 2017 by 7 Comments

If you go to the University of South Florida, you can take the “Makecourse.” The 15-week program promises to teach CAD software, 3D printing, Arduino-based control systems, and C++. Don’t go to the University of South Florida? No worries. Professor [Rudy Schlaf] and [Eric Tridas] have made the entire course available online. You can see several videos below, but there are many more. The student project videos are great, too, like [Catlin Ryan’s] phase of the moon project (see below) or [Dustin Germain’s] rover (seen above).

In addition to a lesson plan and projects, there’s a complete set of videos (you can see a few below). If you are a regular Hackaday reader, you probably won’t care much about the basic Arduino stuff and the basic electronics–although a good review never hurts anyone. However, the more advanced topics about interrupts, SDCards, pin change interrupts might be just the thing. If you ever wanted to learn Autodesk Inventor, there are videos for that, too.

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Gain Access To Science Two Ways

April 15, 2017 by 56 Comments

Not a hack, but something we’ve been wanting to see forever is open access to all scientific publications. If we can soapbox for a few seconds, it’s a crying shame that most academic science research is funded by public money, and then we’re required to pay for it again in the form of journal subscriptions or online payments if we want to read it. We don’t like science being hidden behind a paywall, and neither do the scientists whose work is hidden from wider view.

Here are two heartening developments: Unpaywall is a browser extension that automates the search for pre-press versions of a journal article, and the Bill and Melinda Gates Foundation are denying rights to research that it has funded if the resulting publications aren’t free and open.

The concept of “publishing” pre-print versions of academic papers before publication is actually older than the World Wide Web — the first versions of what would become arXiv.org shared LaTeX version of physics papers and ran on FTP and Gohper. The idea is that by pushing out a first version of the work, a scientist can get early feedback and lay claim to interesting discoveries prior to going through the long publication process. Pre-prints are available in many other fields now, and all that’s left for you to do is search for them. Unpaywall searches for you.

Needless to say, this stands to take a chunk out of the pocketbooks of scientific publishers. (Whether this matters in comparison to the large fees that they charge libraries, universities, and other institutional subscribers is open to speculation.) The top-tier journals — Nature, Science, the New England Journal of Medicine, and others — have been reluctant to offer open access, so brilliant scientists are faced with the choice of making their work openly available or publishing in a prestigious journal, which is good for their career.

In a step to change the status quo, the Bill and Melinda Gates Foundation took their ball and went home; research funded with their money has to be open-access, period. We think that’s a laudable development, and assuming that the foundation funds quality research, the top-tier journals will be losing out unless they cooperate.

To be fair to the journal publishers, many journals are open-access or have open-access options available. The situation today is a lot better than it was even five years ago. But if we had a dime for every time we try to research some scientific paper and ran into a paywall, we wouldn’t be reduced to hawking snazzy t-shirts.

Thanks [acs] for the tip!

Easy DIY Microfluidics

April 15, 2017 by 10 Comments

Microfluidics, the precise control and manipulation of small volumes of liquids, is heavily used in any field that does small-scale experiments with expensive reagents (We’re looking at you, natural sciences.) However, the process commonly used to create microfluidic devices is time and experience intensive. But, worry not: the Uppsala iGEM team has created Chipgineering: A manual for manufacturing a microfluidic chip.

Used while developing everything from inkjet print heads to micro-thermal technologies, microfluidic systems are generally useful. Specifically, Uppsala’s microfluidic device performs a simple biological procedure, a heat-shock transformation, as a proof of concept. Moreover, Uppsala uses commonly available materials: ready to pour PDMS (a biologically compatible silicon) and a 3D printed mold. Additionally, while the team used a resin 3D printer, there seems to be little reason that a fused deposition modeling (FDM) printer wouldn’t work just as well. Particularly interesting is how they sandwich their PDMS between two plates, potentially allowing easy removal and replacement of reagents without external mechanisms. And, to put the cherry on top, Uppsala’s well-illustrated documentation is a joy to read.

This isn’t the first time we’ve covered microfluidic devices, and if you’re still in the prototyping phase, these microfluidic LEGO-like blocks might be what you need. But, if you prefer macrofluidics, this waste shark that aims to clean our oceans might be more your style.

An Interactive Oasis At Burning Man

April 15, 2017 by 13 Comments

An oasis in the desert is the quintessential image of salvation for the wearied wayfarer. At Burning Man 2016, Grove — ten biofeedback tree sculptures — provided a similar, interactive respite from the festival. Each tree has over two thousand LEDs, dozens of feet of steel tube, two Teensy boards used by the custom breath sensors to create festival magic.

Grove works like this: at your approach — detected by dual IR sensors — a mechanical flower blooms, meant to prompt investigation. As you lean close, the breath sensors in the daffodil-like flower detect whether you’re inhaling or exhaling, translating the input into a dazzling pulse of LED light that snakes its way down the tree’s trunk and up to the bright, 3W LEDs on the tips of the branches.

Debugging and last minute soldering in the desert fixed a few issues, before setup — no project is without its hiccups. The entire grove was powered by solar-charged, deep-cycle batteries meant to least from sunset to sunrise — or close enough if somebody forgot to hook the batteries up to charge.

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Hackaday Prize Entry: Hot Logic

April 15, 2017 by 33 Comments

A few weeks ago, [Yann] was dumpster diving and found something of interest. Two vacuum tubes, an ECC83S and an EL84. This was obviously the droppings of a local guitarist, but [Yann] wanted to know if he could build something useful out of them. An amplifier is far too pedestrian, so he settled on a vacuum tube computer.

The normal pentodes and triodes you’ll find in a tube amp require a lot of support components like output transformers, tube sockets, and high voltage power supplies. This was a little too complicated for a tube computer, but after a little bit of searching, [Yann] found a better option for his MINIVAC — subminiature vacuum tubes. These require fewer support components, and can be found for very reasonable prices through the usual component suppliers. His entry for this year’s Hackaday Prize is Hot Logic. It’s a computer — or at least computer components — built out of these tubes.

The tubes in question are a few 1Ж29Б-В and 6Н21Б tubes, a vacuum pentode and dual triode, respectively. Add in a few diodes, and that meets the requirements for being sufficient to build a computer. As a neat little bonus, these tubes have requirements that are very easy to meet. The filament on the 1Ж29Б-В tube only needs 1.2 Volts.

These subminiature tubes are a little underappreciated in the world of audiophililia and DIY electronics. That’s a bit of a shame; these tubes are the most technologically advanced vacuum-based technology ever created. They were the heart and the brains of ballistic missiles, and if you look hard enough you source hundreds of them at very reasonable prices. A vacuum tube computer requires a lot of tubes, and if anyone will be able to build a vacuum tube computer it’s going to be [Yann] and his pile of Soviet surplus.

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Mains Clocking A Microcontroller

April 15, 2017 by 34 Comments

[Lujji] is playing around with the STM8 microcontroller. In reviewing the official documentation for this chip, he read the external clock can be a sine wave, a triangle wave, or a square wave with a 50% duty cycle. The minimum CPU frequency is 0 Hz. [Lujji] doesn’t have a signal generator, and presumably, he’s all out of crystals. He does have mains AC, though, so why not clock a microcontroller with wall power?

Using mains power as a frequency standard is a concept a hundred years old. Synchronous motors turn at a rate proportional to the mains frequency, and this has been used in clocks for decades. If you’re really clever, you can clock digital circuits with mains AC, but we’ve never seen someone replace a tiny crystal in a microcontroller circuit with mains power.

After an experiment to prove the concept, [Lujji] went on to construct a circuit that wasn’t as dumb as connecting the microcontroller directly to a wall socket. The direct approach didn’t work that well anyway — the STM8 didn’t like low frequency clocks with slow edges. [Lujji] needed a clock with cleaner edges, and a 555 configured as a comparator fit the bill.

The completed circuit sends mains power through an optocoupler to drive a 555 configured as a comparator. The output is a clean 50Hz clock that is connected to the OSCIN pin on an STM8. This is now a chip running at 50Hz, and yes, it works. [Lujji] set up a circuit to write ‘Hello World’ on an old Nokia LCD. That took about three minutes. It works, though, even though it’s completely useless. Maybe this can be applied to some novel timekeeping similar to that one-instruction-per-day clock we looked earlier in the year.