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Hackaday Links: June 18, 2023

Will it or won’t it? That’s the question much on the minds of astronomers, astrophysicists, and the astro-adjacent this week as Betelgeuse continued its pattern of mysterious behavior that might portend a supernova sometime soon. You’ll recall that the red giant star in the constellation Orion went through a “great dimming” event back in 2019, where its brightness dipped to 60% of its normal intensity. That was taken as a sign that perhaps the star was getting ready to explode — or rather, that the light from whatever happened to the star 548 years ago finally reached us — and was much anticipated by skywatchers, yours truly included. As it turned out, the dimming was likely caused by Betelgeuse belching forth an immense plume of dust, temporarily obscuring our view of its light. Disappointing.

Those who gave up on the hope of seeing a supernova might have done so too fast, though, because now, the star seems to be swinging the other way and brightening. It briefly became the brightest star in Orion, nearly outshining nearby Sirius, the brightest star in the sky. So what does all this on-again, off-again business mean? According to Dr. Becky, a new study — not yet peer-reviewed, so proceed with caution — suggests that the star could go supernova in the next few decades. The evidence for this is completely unrelated to the great dimming event, but by analyzing the star’s long history of variable brightness. The data suggest that Betelgeuse has entered the carbon fusion phase of its life, a period that only lasts on the scale of a hundred years for a star that size. So we could be in for the ultimate fireworks show, which would leave us with a star brighter than the full moon that’s visible even in daylight. And who doesn’t want to see something like that?

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Tech In Plain Sight: Air Conditioning

I’m always amazed that technology can totally wipe out industries. Sure, some people make a living making horseshoes, for example, but the demand for them is way down compared to what it would have been when horses were the normal mode of transportation. But even so, people still make horseshoes. But think about the ice harvesting business. Never heard of it? Turns out, before refrigeration, there was a huge business of moving ice from where it naturally occurred to other places and storing it, usually underground with a lot of insulation. As far as I know, that business — including the neighborhood ice man — is totally gone now except for some historical exhibitions. We take refrigeration and air conditioning for granted, but it hasn’t been that long ago that ice was a luxury and your own reprieve from the heat was a fan.

Early Cooling

The story starts a little earlier than you might expect. In the 1840s, physician John Gorrie was concerned about “the evils of high temperature.” His hospital in Florida imported ice using the aforementioned ice trade and it wasn’t cheap nor was it very effective.

Undeterred, he developed a machine that used a horse, a waterwheel, steam, or wind power to drive a compressor to create ice. He got a patent in 1851 but it failed to catch on before his financial backer died. In fact, Oliver Evans had the idea in 1805 but never built a working machine. Jacob Perkins patented the first compression cooler in 1834, again with little practical use.

When U.S. President Garfield was shot, Navy engineers built a cooling box using cloths soaked in ice water to cool the president’s hospital room by 20 degrees. Since the mortally wounded president survived 80 days after the shooting, we presume he appreciated the comfort.

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Building A New RF Remote From Scratch

We’ve seen no shortage of projects that use the ESP8266 or ESP32 to add “smart” features to existing home appliances, often by pairing the microcontroller with a radio or IR transmitter. If your device has an existing remote, integrating it into a custom home automation system is often just a matter of getting a few cheap modular components and writing some simple code to glue it all together.

But what if the appliance you want to control doesn’t use a common frequency? That’s a question that [eigma] recently had to answer after finding the remote control for the bedroom ceiling fan was operating at a somewhat unusual 304 MHz. Something like the MAX1472 could probably have been tuned to this frequency, but the chip doesn’t seem to be available in a turn-key module as the popular 315 MHz transmitters are.

There were a few possible options, including using a software defined radio (SDR), but [eigma] didn’t want to spend a fortune on this project or wait months for parts to get shipped from overseas. The most straightforward solution was to design a custom transmitter tuned to the proper frequency using discrete components; something of a dark art to those of us who’ve been spoiled by the high availability of modular components.

What follows is an fascinating look at the design, testing, and troubleshooting of a truly scratch-built transmitter. You won’t find any ICs here, the carrier signal is generated with just a transistor, some carefully measured pieces of wire, and a handful of passive components. By modulating the signal with an ESP32, [eigma] successfully makes the oddball ceiling fan an honorary member of the Internet of Things.

The write-up that [eigma] has done is an absolutely invaluable resource if you ever find yourself in need of rolling a bespoke transmitter. It easily ranks among some of the most informative radio reverse engineering work we’ve covered, and you’d be wise to file this one away for future reference. That said, most of the newer hardware you’re going to run into will probably be utilizing a widely-supported frequency like 433 MHz.

Automate The Freight: Shipping Containers Sorted By Robot Stevedores

Towering behemoths are prowling the docks of Auckland, New Zealand, in a neverending shuffle of shipping containers, stacking and unstacking them like so many out-sized LEGO bricks. And they’re doing it all without human guidance.
It’s hard to overstate the impact containerized cargo has had on the modern world. The ability to load and unload ships laden with containers of standardized sizes rapidly with cranes, and then being able to plunk those boxes down onto a truck chassis or railcar carrier for land transportation has been a boon to the world’s economy, and it’s one of the main reasons we can order electronic doo-dads from China and have them show up at our doors essentially for free. At least eventually.
As with anything, solving one problem often creates other problems, and containerization is no different. The advantages of being able to load and unload one container rather than separately handling the dozen or more pallets that can fit inside it are obvious. But what then does one do with a dozen enormous containers? Or hundreds of them?
That’s where these giant self-driving cranes come in, and as we’ll see in this installment of “Automate the Freight”, these autonomous stevedores are helping ports milk as much value as possible out of containerization.

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Laser-Cut Modular Toolbox

[ystoelen] created this modular wooden toolbox out of laser-cut 5mm plywood secured with leather hinges bolted into place. The leather strips secure the various tool boards with grommets connecting to plastic plugs. The toolboards use cross-shaped holes with laser-cut plugs and strips of elastic securing the tools, allowing each board to be uniquely configured depending on what tool is being stored there. There is a larger, “main” board, onto which smaller boards can be placed depending on what tools you’ll need.

While this is a clever approach to tool transport, we have some concerns about this project. Usually the problem with a box full of tools is that you’ve overloaded it and can’t readily lift it up. Often this involves a steel toolbox that won’t break, no matter what happens. But a plywood construct isn’t nearly that strong, and if overloaded or dropped it’s gonna take some damage.

For more toolbox inspirations, read our posts on a machine shop in a toolbox as well as this Transformers-themed portable workbench.

 

Climbing Bike Storage Thwarts Thieves?

If you’ve got an expensive bike and don’t mind carrying around a whole bunch of extra weight in your courier bag you’ll like this concept. A design team built a pole-climbing bike rack in about 14 days. The video after the break shows the prototyping process as well as the finished “lock” in use. It’s a commercial for the company that employs the designers, but this is one kind of advert we don’t mind watching.

Square channel makes up the body of the device, with a set of Rollerblade wheels which grab a light pole and use three 12V gear motors for climbing. The controller is a wireless fob similar to those used for keyless entry on cars. In the video you can hear the cliché sound of a car alarm being set once the carrier reaches its finished height. Nice.

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Aircraft Carrier Is Moving Target For Autonomous Quadcopter

[Karl-Engelbert Wenzel] developed a UAV capable of taking off and landing on a moving platform autonomously. The platform operates aircraft-carrier-style by driving around the room in circles. The quadcopter tracks a grid of IR LEDs at the front of the landing deck by using the IR camera from a Wii remote. The best part is that the flight controls and processing are all done by the copter’s onboard ATmega644 processor, not requiring a connection to a PC. The landings are quite accurate, achieving a maximum error of less than 40 centimeters. In the video after the break you can see the first landing is slightly off the mark but the next two are dead on target.

So build yourself a mobile platform and pair it up with your newly finished quadcopter to replicate this delightful hack.

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