Wind-to-Heat: A Lot Of Hot Air?

June 27, 2023 by Zoe Skyforest 87 Comments

Heating is one of the greatest uses of energy in human society today. Where we once burned logs to stave off the brutal winter chill, now we lean on gas and electricity to warm our homes and keep us safe and toasty. In some colder climates, like the UK, heating can make up 60-80% of total domestic energy demands.

However, there are alternative ways to provide heating. Using wind energy to directly provide heat could be key in this area, using a variety of interesting methods that could have some unique niche applications.

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Meshtastic For The Greater Good

June 26, 2023 by Jonathan Bennett 62 Comments

Last week, my city was hit by a tornado. That’s not surprising here in Oklahoma, and thankfully this event was an F0 or possibly even an EF0 — a really weak tornado. Only a couple roofs collapsed, though probably half the houses in town are going to need roof repairs, thanks to the combination of huge hail and high winds. While it wasn’t too bad, power did go down in a few places around town, and this led to an interesting series of events.

Chat messages were coming in like this: “That was a [power] flicker, yeah. Even took down my Internet.” Followed by “Whee, [fiber Internet] got knocked out and now Starlink has too many clouds in the way.” And after ten minutes of silence, we got a bit worried to see “Time to hide under a bed. … Is cell service back?” It is a bit spooky to think about trying to help neighbors and friends after a disaster, in the midst of the communication breakdown that often follows. If he had needed help, and had no working communications, how long would it have taken for us to go check on him?
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Et Tu, Red Hat?

June 23, 2023 by Jonathan Bennett 94 Comments

Something odd happened to git.centos.org last week. That’s the repository where Red Hat has traditionally published the source code to everything that’s a part of Red Hat Enterprise Linux (RHEL) to fulfill the requirements of the GPL license. Last week, those packages just stopped flowing. Updates weren’t being published. And finally, Red Hat has published a clear answer to why:

Red Hat has decided to continue to use the Customer Portal to share source code with our partners and customers, while treating CentOS Stream as the venue for collaboration with the community.

Sounds innocuous, but what’s really going on here? Let’s have a look at the Red Hat family: RHEL, CentOS, and Fedora.

RHEL is the enterprise Linux distribution that is Red Hat’s bread and butter. Fedora is RHEL’s upstream distribution, where changes happen fast and things occasionally break. CentOS started off as a community repackaging of RHEL, as allowed under the GPL and other Open Source licenses, for people who liked the stability but didn’t need the software support that you’re paying for when you buy RHEL.

Red Hat took over the reigns of CentOS back in 2014, and then imposed the transition to CentOS Stream in 2020, to some consternation. This placed CentOS Stream between the upstream Fedora, and the downstream RHEL. Some people missed the stability of the old CentOS, and in response a handful of efforts spun up to fill the gap, like Alma Linux and Rocky Linux. These projects took the source from git.centos.org, and rebuilt them into usable community operating systems, staying closer to RHEL in the process.

Red Hat has published a longer statement elaborating on the growth of CentOS Stream, but it ends with an interesting statement: “Red Hat customers and partners can access RHEL sources via the customer and partner portals, in accordance with their subscription agreement.” What exactly is in that subscription agreement? Well according to Alma Linux, “the way we understand it today, Red Hat’s user interface agreements indicate that re-publishing sources acquired through the customer portal would be a violation of those agreements.” Continue reading “Et Tu, Red Hat?” →

China Plans Its Own Megaconstellation To Challenge Starlink

June 22, 2023 by Zoe Skyforest 39 Comments

Satellite internet used to be a woeful thing. Early networks relied on satellites in geostationary orbits, with high latency and minimal bandwidth keeping user demand low. That was until Starlink came along, and provided high-speed, low-latency internet access using a fleet of thousands of satellites in Low Earth orbit.

Starlink has already ruffled feathers due to concerns around light pollution and space junk in particular. Now, it appears that China may be readying its own competing constellation to avoid being crowded out of low orbits by the increasingly-popular service.

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Congratulations To Our Op-Amp Challenge Winners!

June 21, 2023 by Elliot Williams 15 Comments

The real world is analog, and the op-amp is the indispensable building block of many analog circuits. We wanted to give you analog fanatics out there a chance to shine and to encourage our digital brothers and sisters to dip their toes in the murky waters where ones and zeroes define the ends of a spectrum rather than representing the only choice. Hence, we presented the Op Amp Challenge. And you did not disappoint!

We received 83 entries, and it was extraordinarily hard to pick the winners. But since we had three $150 DigiKey shopping sprees to give away, our six judges buckled down and picked their favorites. Whether or not you’ve got the Golden Rules of the ideal op-amp tattooed on your arm, you’ll enjoy looking through all of the projects here. But without further ado…

The Winners

[Craig]’s Op Art is an X-Y voltage generator to plug into an oscilloscope and make classic Lissajous and other spirograph-like images, and it’s all done in analog. Maybe it was his incredible documentation, the nice use of a classic three-op-amp tunable oscillator, or the pun hidden in the title. Whatever the case, it wowed our judges and picked up a deserved place in the top three.

Hearkening back to the pre-digital dinosaur days, [Rainer Glaschick]’s Flexible Analog Computer is a modular analog computer prototyping system on a breadboard backplane. Since you have to re-wire up an analog computer for your particular, it’s great that [Rainer] gave us a bunch of examples on his website as well, including a lunar lander and classic Lorenz attractor demos.

And there was no way that [Chris]’s interactive analog LED wave array wouldn’t place in the top three. It’s a huge 2D analog simulation that runs entirely on op-amps, sensing when your hand moves across any part of its surface and radiating waves out from there. You have to admire the massive scale here, and you simply must check out the video of it in action. Glorious!

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Cottonization: Making Hemp And Flax Fibers Into The Better Cotton

June 20, 2023 by Maya Posch 16 Comments

These days it’s hard to imagine that fabrics were ever made out of anything other than cotton or synthetic fibers, yet it wasn’t too long ago that hemp and flax-based fabrics — linen — were the rule rather than the exception. Cotton production has for centuries had the major disadvantages of requiring a lot of water and pesticides, and harvesting the cotton was very labor-intensive, making cotton rather expensive. In order to make separating the cotton fibers from the seed easier, improved versions of the cotton gin (‘cotton engine’) were developed, with the 19th century’s industrial revolution enabling a fully automated version.

What makes cotton attractive is the ease of processing these fibers, which are part of the seed pod. These fibers are 25 mm – 60 mm long, 12 μm – 45 μm fine fibers that can be pulled off the seeds and spun into yarn or whatever else is needed for the final product, much like wool. Hemp and flax fibers, in contrast, are extracted from the plant stem in the form of bast fibers. Rather than being pure cellulose, these fibers are mostly a mixture of cellulose, lignin, hemicellulose and pectin, which provide the plant with rigidity, but also makes these fibers coarse and stiff.

The main purpose of cottonization is to remove as much of these non-cellulosic components as possible, leaving mostly pure cellulose fibers that not only match the handleability of cotton fibers, but are also generally more durable. Yet cottonization used to be a long and tedious process, which made bast fiber-based textiles expensive. Fortunately, the steam explosion cottonization method that we’ll be looking at here may be one of the methods by which the market will be blown open for these green and durable fibers.

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Review: InfiRay P2 Pro Thermal Camera

June 19, 2023 by Tom Nardi 65 Comments

It probably won’t surprise you to learn that Hackaday is constantly hounded by companies that want us to review their latest and greatest gadget. After all, getting us to post about their product is cheaper, easier, and arguably more effective than trying to come up with their own ad campaign. But if you’ve been with us for awhile, you’ll also know that in-house reviews aren’t something we actually do very often.

The reason is simple: we’re only interested in devices or products that offer something useful or unique to this community. As such, the vast majority of these offers get ignored. I’ll give you an example. For whatever reason, multiple companies have been trying desperately to send me electric bikes with five-figure price tags this year. But since there’s no obvious way to turn that into useful content for the readers of Hackaday, I’m still stuck pedaling myself around like it’s the 1900s. I kid of course…I haven’t dared to get on a bike in a decade.

So I don’t mind telling you that, when InfiRay contacted me about reviewing their P2 Pro thermal camera, the email very nearly went into the trash. We’ve seen these kind of phone-based thermal cameras before, and it seemed to be more of the same. But after taking a close look at the specs, accessories, and claims laid out in the marketing material, I thought this one might be worth checking out first-hand.

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