Ethanol-Powered Arduinos

Following the time-honored YouTube tradition of ordering cheap stuff online and playing with it while the camera runs, [Monta Elkins] bought a Stirling engine that drives a DC motor used as a generator. How much electrical juice can this thing provide, running on just denatured alcohol? (Will it blend?)

The answer is probably not really a spoiler: it generates enough to run “Blink.ino” on a stock Arduino, at least when powered directly through the 5 V rail. [Monta] recorded an open-circuit voltage of around 5 V, and a short-circuit current of around 100 mA at a measured few hundred millivolts. …read more

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A Real Hacker’s IDE

We don’t use a GUI IDE, but if we did, it would most certainly be something along the lines of [Martin]’s embedded-IDE project. We’ve always felt that most IDEs are just fancy wrappers around all the tools that we use anyway: Makefiles, diff, git, ctags, and an editor. [Martin]’s project makes them less fancy, more transparent, and more customizable, while retaining the functionality. That’s the hacker’s way — putting together proven standard tools that already work.

The code editor he uses is QScintilla, which uses clang for code completion. The “template” system for new projects? He uses …read more

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A Tool For KiCad Board Renderings

If you’re producing documentation for a PCB project, you might as well make the board renders look good. But then, that’s a lot of work and you’re not an artist. Enter [Jan]’s new tool that takes KiCad board files, replaces each footprint with (custom) graphics, and provides a nice SVG representation, ready for labelling. If you like the output of a Fritzing layout, but have higher expectations of the PCB tool, this is just the ticket.

We all love [pighixx]’s pinout diagrams. Here’s his take on the Arduino Uno, for instance. It turns out that he does these largely by …read more

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Mangling Images With Audio Effects

Ever wonder what those snapshots you took of your trip to Paris would look like if you ran them through a Proco RAT or a Boss Overdrive? How about a BF-3 flanger? [Robert Foss] wrote in with this nifty little script (GitHub) that processes images as if they were audio files so that you can try it out without investing in a rack of analog pedals. Test your audio/visual DSP intuition and see if you can name the images without looking at the effects.

If you know your Linux command-line utilities, there’s really not much to it — scroll down …read more

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Gain Access to Science Two Ways

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 …read more

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High Vacuum with Mercury and Glassware

If you want to build your own vacuum tubes, whether amplifying, Nixie or cathode-ray, you’re going to need a vacuum. It’s in the name, after all. For a few thousand bucks, you can probably pick up a used turbo-molecular pump. But how did they make high vacuums back in the day? How did Edison evacuate his light bulbs?

Strangely enough, you could do worse than turn to YouTube for the answer: [Cody] demonstrates building a Sprengel vacuum pump (video embedded below). As tipster [BrightBlueJim] wrote us, this project has everything: high vacuum, home-made torch glassware, and large quantities of toxic …read more

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High Vacuum with Mercury and Glassware

If you want to build your own vacuum tubes, whether amplifying, Nixie or cathode-ray, you’re going to need a vacuum. It’s in the name, after all. For a few thousand bucks, you can probably pick up a used turbo-molecular pump. But how did they make high vacuums back in the day? How did Edison evacuate his light bulbs?

Strangely enough, you could do worse than turn to YouTube for the answer: [Cody] demonstrates building a Sprengel vacuum pump (video embedded below). As tipster [BrightBlueJim] wrote us, this project has everything: high vacuum, home-made torch glassware, and large quantities of toxic …read more

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Say It With Me: Root-Mean-Square

If you measure a DC voltage, and want to get some idea of how “big” it is over time, it’s pretty easy: just take a number of measurements and take the average. If you’re interested in the average power over the same timeframe, it’s likely to be pretty close (though not identical) to the same answer you’d get if you calculated the power using the average voltage instead of calculating instantaneous power and averaging. DC voltages don’t move around that much.

Try the same trick with an AC voltage, and you get zero, or something nearby. Why? With an AC …read more

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DIY DynDNS with ESP8266 and Dweets

You’re on a home router, and your IP address keeps changing. Instead of paying a little bit extra for a static IP address (and becoming a grownup member of the Internet) there are many services that let you push your current IP out to the rest of the world dynamically. But most of them involve paying money or spending time reading advertisements. Who has either money or time?!

[Alberto Ricci Bitti] cobbled together a few free services and an ESP8266 module to make a device that occasionally pushes its external IP address out to a web-based “dweet” service. The skinny: …read more

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Hackaday Trims Its Own Resistors

There are times when you might want an odd-value resistor. Rather than run out to the store to buy a 3,140 Ω resistor, you can get there with a good ohmmeter and a willingness to solder things in series and parallel. But when you want a precise resistor value, and you want many of them, Frankensteining many resistors together over and over is a poor solution.

Something like an 8-bit R-2R resistor-ladder DAC, for instance, requires seventeen resistors of two values in better than 0.4% precision. That’s just not something I have on hand, and the series/parallel approach will get …read more

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