Can Open-source Hardware Be Like Open-source Software?

February 27, 2018 by Elliot Williams 116 Comments

Hardware and software are certainly different beasts. Software is really just information, and the storing, modification, duplication, and transmission of information is essentially free. Hardware is expensive, or so we think, because it’s made out of physical stuff which is costly to ship or copy. So when we talk about open-source software (OSS) or open-source hardware (OSHW), we’re talking about different things — OSS is itself the end product, while OSHW is just the information to fabricate the end product, or have it fabricated.

The fabrication step makes OSHW essentially different from OSS, at least for now, but I think there’s something even more fundamentally different between the current state of OSHW and OSS: the pull request and the community. The success or failure of an OSS project depends on the community of people developing it, and for smaller projects that can hinge on the ease of a motivated individual digging in and contributing. This is the main virtue of OSS in my opinion: open-source software is most interesting when people are reading and writing that source.

With pure information, it’s essentially free to copy, modify, and push your changes upstream so that others can benefit. The open hardware world is just finding its feet in this respect, but that’s changing as we speak, and I have great hopes. Costs of fabrication are falling all around, open and useful tools are being actively developed to facilitate interchange of the design information. I think there are lessons that OSHW can learn from the OSS community’s pull-request culture, and that will help push the hardware hacker’s art forward.

What would it take to get you to build someone else’s OSHW project, improve on it, and contribute back? That’s a question worth a thoughtful deep dive.

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Mechanical Clocks That Never Need Winding

February 25, 2018 by Elliot Williams 32 Comments

What is it about mechanical clocks? Maybe it’s the gears, or the soft tick-tocking that they make? Or maybe it’s the pursuit of implausible mechanical perfection. Combine mechanical clocks with “free” energy harvested from daily temperature and pressure variation, and we’re hooked.

Both the Beverly Clock, built by Arthur Beverly in 1864, and the Atmos series of clocks built between 1929 and 1939, run exclusively on the expansion and contraction of a volume of air (Beverly) or ethyl chloride (Atmos) over the day to wind up the clock via a ratchet. The Beverly Clock was apparently a one-off, and it’s still running today. And with over 500,000 Atmos clocks produced, there must be some out there.

Although we had never heard of it, this basic idea is really old. Clicking through Wikipedia (like you do!) got us to Cox’s Timepiece, which is powered by the movement of 68 kg of mecury under atmospheric pressure. It is currently not running, but housed in the Victoria and Albert Museum in London. Even older is a clock that we couldn’t find any info on that dates from 1620, invented by Cornelius Drebbel. Anyone know anything?

We’ve had energy harvesting on our mind lately, and the article on the Beverly Clock says that it gets 31 μWh over a day when the temperature swings by 3.3 °C. Put into microcontroller perspective, this is 0.39 μA at 3.3 V, so you’ll have to be pretty careful about your sleep modes, and an LED is out of the question. How amazing is it, then, that this can power a mechanical clock?

Thanks [Luke], [hex4def6], and [Wallace Owen] for tipping us off to these in the comment section!

OpenSCAD: Tieing It Together With Hull()

February 13, 2018 by Elliot Williams 40 Comments

What’s your favorite OpenSCAD command? Perhaps it’s intersection() or difference()? Or are you a polygon() and extrude() modeler? For me, the most useful, and maybe most often overlooked, function is hull(). Hull() does just what it says on the can — creates a convex hull around the objects that are passed to it as children — but that turns out to be invaluable.

Hull() solves a number of newbie problems: making things round and connecting things together. And with a little ingenuity, hull() can provide a nearly complete modelling strategy all on its own. If you use OpenSCAD and your creations end up with hard edges, or you spend too much time figuring out angles, or if you just want to experience another way to get the job done, read on!

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You Can Learn A Lot From A Blinkenrocket

February 2, 2018 by Elliot Williams 8 Comments

At this year’s Chaos Communication Congress, we caught up with [muzy] and [overflo], who were there with a badge and soldering project they designed to teach young folks how to solder and program. Blinkenrocket is a basically a 64-LED matrix display and just enough support hardware to store and display animations, and judging by the number of blinking rockets we saw around the necks of attendees, it was a success.

Their talk at 34C3 mostly concerns the production details, design refinements, and the pitfalls of producing thousands of a thing. If you’re thinking of building a hardware kit or badge on this scale, you should really check it out and crib some of their production optimization tricks.

For instance, instead of labelling the parts “C2” or “R: 220 Ohms”, they used a simple color-coding scheme. This not only makes it easier for kids to assemble, but it also means that they didn’t have to stick 1,000 part labels on every component. Coupled with [overflo]’s Zerhacker, SMD parts in strips were cut to the right length and color-coded in one step, done by machine.

The coolest feature of the Blinkenrocket itself is the audio programming interface. It’s like in the bad old days of software stored on cassette tapes, but it’s a phenomenal interface for getting a simple animation out of a web app and straight into a piece of minimal hardware — just plug it into a laptop or cell phone’s audio out and press “play” in the browser. The original design tried to encode the data in the pulse-length of square waves, but this turned out to be very hardware dependent. The final design used frequency-shift keying. What’s old is new again.

Everything you could want to know about the design, its code, and even the website itself are up on the project’s GitHub page, so go check it out. If you’d like to arrange a Blinkenrocket workshop yourself, shoot [muzy] or [overflo] an e-mail. Full disclosure: [overflo] gave us a kit, the “hard-mode” SMD one with ~~0805~~ 1206 parts, and it was fun to assemble and program.

Before…

After

Amazing Mechanical Linkages And The Software To Design Them

January 26, 2018 by Elliot Williams 54 Comments

Most of us are more bits-and-bytes than nuts-and-bolts, but we have the deepest appreciation for the combination of the two. So, apparently, does [rectorsquid]. Check out the design and flow of his rolling ball sculpture (YouTube, embedded below) to see what we mean. See how the arms hesitate just a bit as the ball is transferred? See how the upper arm gently places it on the ramp with a slight downward gesture? See how it’s done with one motor? There’s no way [rectorsquid] designed this on paper, right?

Of course he didn’t (YouTube). Instead, he wrote a simulator that lets him try out various custom linkages in real time. It’s a Windows-only application (sigh), but it’s free to use, while the video guides (more YouTube) look very comprehensive and give you a quick tour of the tool. Of special note is that [rectorsquid]’s software allows for sliding linkages, which he makes very good use of in the rolling ball sculpture shown here.

We’ve actually secretly featured [rectorsquid]’s Linkage software before, in this writeup of some amazing cosplay animatronic wings that used the program for their design. But we really don’t want you to miss out if you’re doing mechanical design and need something like this, or just want to play around.

If you’d like to study up on your nuts and bolts, check out our primer on the ubiquitous four-bar linkage, or pore through Hackaday looking for other great linkage-powered examples, like this automatic hacksaw or a pantograph PCB probe for shaky hands.

Anyone know of an open-source linkage simulator that can also output STL files for 3D printing? Or in any format that could be easily transformed into OpenSCAD? Asking for a “friend”.

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Build An Excellent Coffee Roaster With A Satisfyingly Low Price Tag

January 23, 2018 by Elliot Williams 62 Comments

There’s a lot of mysticism around coffee roasting, but in the end it couldn’t be simpler. Take a bunch of beans, heat them up evenly, and stop before they get burned. The rest is details.

And the same goes for coffee roasters. The most primitive roasting technique involves stirring the beans in a pan or wok to keep them from scorching on the bottom. This works great, but it doesn’t scale. Industrial drum roasters heat a rotating drum with ridges on the inside like a cement mixer to keep the beans in constant motion while they pass over a gas fire. Fluidized-bed roasters use a strong stream of heated air to whirl the beans around while roasting them evenly. But the bottom line is that a coffee roaster needs to agitate the beans over a controllable heat source so that they roast as evenly as possible.

My DIY coffee roaster gave up the ghost a few days ago and I immediately ordered the essential replacement part, a hot air popcorn popper, to avert a true crisis: no coffee! While I was rebuilding, I thought I’d take some pictures and share what I know about the subject. So if you’re interested in roasting coffee, making a popcorn popper into a roaster, or even just taking an inside look at a thoroughly value-engineered kitchen machine, read on!

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Great People And Culture At 34th Chaos Communication Congress

January 2, 2018 by Elliot Williams 18 Comments

If you’ve been to a Chaos Communication Congress, you know the feeling — the strange realization after it’s all over that you’re back in the “real world”. It’s somehow alienating and unfriendly in comparison to being surrounded by computer freaks, artists, hackers, activists, coders, and other like-minded individuals over the four days of the Congress. A hand-written poster by the podcasting center read “Endlich, normale Leute” — “At last, normal people” — which is irony piled on irony but the sentiment is still right for certain strange values of “normal”. Normal hackers? You’d probably fit right in.

We cover a lot of the talks from the Congress, because they’re first-class and because you can play along at home, but the real soul of the Congress is people getting together, making something temporary and crazy, talking over their common plans, learning new things directly from one-another, and simply having fun. Here’s our chance to give you a little of the other side of the Congress.
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