Awning Motorized And Automated To Avoid Wind Damage

July 13, 2023 by 30 Comments

Awnings can be architecturally beautiful, and they provide lovely shelter from the sun and even a bit of rain. They don’t always like taking a pounding from high winds though. [Steve Carey] installed some nice awnings, but wanted to avoid any potential issues, so he built an automated system to extend and retract them for him. 

An ESP32 serves as the brains of the operation. It’s set up to open and close the blinds using a high-torque brushed motor run by a BTS7960 motor driver. The motor turns the awning’s rod via a hook, so it can be readily removed in the event [Steve] moves house. Reed switches are used as end stops to ensure the motor stops when the awning is fully open or closed. The ESP32 is hooked up to an accelerometer mounted on the awning. It’s set up to sum the accelerations detected in all three axes, and close the awning in the event conditions get too windy.

There’s a certain peace of mind that comes with having your awning hooked up with a preventative safety system. We don’t have a lot of awning posts on Hackaday, but we have seen a good number of automated blinds in the past. If you’ve been working on your own outdoor home automation gear, be sure to hit up the tipsline! Happy…awnings…ing? Anyway.

 

Timekeeping For Distributed Computers

July 13, 2023 by 14 Comments

Ask any programmer who has ever had to deal with timekeeping on a computer, and they’re likely to go on at length about how it can be a surprisingly difficult thing to keep track of. Time zones, leap years, leap seconds, various timekeeping standards, clock drift, and even relativity are all problems that can creep in to projects. Issues with timekeeping are exacerbated in distributed systems as well, adding another layer of complexity when we need to reliably determine the order that a series of actions occurred across a number of different computers with a high precision. One solution to this problem is the implementation of a vector clock.

When using other systems such as logical clocks to attempt to keep track of the order of events on different computers, a problem that may arise is that these systems don’t always track these changes with perfect reliability due to many issues such as varying temperature, race conditions, or clock skew. The vector clock instead tracks causal relationships between events. Each separate process maintains its own vector clock, represented by a list of integers. When one of these processes performs an event, it increments its own clock and sends it out to the rest of the system. By keeping track of this clock as it is updated by various processes across the computer the distributed system can be much more confident about the order in which events took place.

Of course, there are always downsides with elegant solutions like this. In the case of vector clocks the downside is largely increased overhead for keeping track of all of the sets of integers. But in systems where the ordering of processes is of the upmost importance, this is worth the trade-off to ensure reliability. And unless we hook all of our computers up to atomic clocks like they do for some computers at CERN we will have to take the increased overhead instead.

How Duck Tape Became Famous

July 13, 2023 by 81 Comments

If you hack things in the real world, you probably have one or more rolls of duck tape. Outside of the cute brand name, many people think that duck tape is a malapropism, but in truth it is the type of cloth traditionally used in our favorite tape: cotton duck. However, as we’ll see, it’s not entirely wrong to call it duct tape either. Whatever you call it, a cloth material has an adhesive backing and is coated with something like polyethylene.

Actually, the original duck tape wasn’t adhesive at all. It was simply strips of cotton duck used for several purposes, including making shoes and wrapping steel cables like the ones placed in 1902 at the Manhattan Bridge. By 1910, the tape was made with adhesive on one side and soaked in rubber, found use in hospitals for binding wounds. In May 1930, Popular Mechanics advised melting rubber from an old tire and adding rosin to create a compound to coat cotton tape, among other things.

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Roboticized Zelda Ocarina Plays Itself

July 13, 2023 by 10 Comments

[3DSage] has long been obsessed with a certain type of musical instrument after playing The Legend of Zelda: Ocarina of Time. It spawned a project to robotically control an ocarina, which turned out beautifully.

The first step was to build an air blower that could excite the ocarina into making noise. With that completed, [3D Sage] then 3D scanned an ocarina so he could design a mechanism that would fit the instrument and let it be played. The final design uses a set of solenoids with rubber caps to plug the various holes of the ocarina to play different notes. The solenoids are actuated according to notes pressed on a printed keyboard. Alternatively, it can be programmed to play pre-stored songs by itself.

The results are charming, though the ocarina does sound a little off-pitch. Overall, though, the project is a great use case for a 3D scanner, since the instrument itself is such an odd irregular shape.

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Keeping Thermal Plants Cool Without Breaking The Cooling Water Budget

July 13, 2023 by 19 Comments

Steam generators in thermal (steam-cycle) power plants require a constant influx of cool water to maximize the transfer of thermal energy. How this water is cooled again in the condensor after much of the steam’s thermal energy has been spent in the steam turbines or heat exchangers is a very important consideration in the design and construction of these plants. The most obvious and straightforward system is direct “once-through” cooling, where the water is drawn straight from a nearby river or other body of water and released after passing through the condenser. This type of system is by far the cheapest, but is also impacted by both the seasons and environmental considerations.

Where cool surface water is less abundantly available, evaporative cooling in a recirculating system such as with spray ponds and cooling towers is a good alternative. Although slightly more costly, a big benefit of these is that they require far less water and have much more control over the intake water temperature, which can raise plant efficiency. Finally, dry cooling is essentially a closed-loop system, which is exceedingly useful in areas where water is scarce. This latter type of cooling is what allows thermal plants to operate even in desert regions.

As the global climate changes – with more extreme weather events – picking the right cooling solution is more important than ever, and has us looking at retrofitting existing thermal plants with more efficient solutions. If you were ever curious how power plants keep the cool side cool, read on!

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Listening In On A Deep-Space Satellite As It Returns Home

July 13, 2023 by 1 Comment

We’ve covered dozens of projects about getting images of Earth’s weather straight from the source. It’s not too much of a trick to download images straight from our constellation of weather satellites, but what about space weather? We’ve got satellites for that too, of course, but to get a good look at the Sun, they’re out of reach of most homebrew ground stations.

That’s about to change, though, as STEREO-A returns to our neighborhood after a 17-year absence, making citizen science a reasonable proposition. The STEREO mission — Solar Terrestrial Relations Observatory — was launched in 2006 with a pair of satellites in heliocentric orbits. STEREO-B was lost in 2014 due to a navigational glitch, but STEREO-A has spent a lot of the intervening years watching the backside of the Sun relative to the Earth. As [Scott Tilley] explains, the satellite is now approaching inferior conjunction, where it will pass between the Earth and the Sun.

This close pass makes STEREO-A’s X-band deep-space beacon readily available to hobbyist-scale equipment, like [Scott]’s 66-cm dish antenna. The dish is mounted on an alt-az telescope mount for tracking, and sports a host of gear at the focus, like LNAs, filters, mixers, and an Ettus B200 SDR. It’s not a cheap setup, but compared to what’s usually needed to listen to STEREO-A, it’s a bargain. The process of demodulating and decoding the signals was a bit more involved, though, requiring not only SatDump and some custom code but also a lot of patience. The images are worth the wait, though; [Scott] shares some amazing shots of our increasingly active Sun as well as animations of recent sunspot activity.

If you’re interested in getting in on the STEREO-A action, you’d better get hopping — the satellite will only be in the neighborhood for a few more months before heading off for another pass around the back of the Sun.

Recreating The Golden Era Of Cable TV

July 13, 2023 by 55 Comments

Fewer and fewer people have cable TV subscriptions these days, due to a combination of poor business practices by cable companies and the availability of alternatives to cable such as various streaming platforms. But before the rise of the Internet that enabled these alternatives, there was a short period of time where there were higher-quality channels, not too many commercials, a possibly rose-tinted sense of wonder, and where MTV actually played music. [Irish Craic Party] created this vintage cable TV network to capture this era of television history.

The hardware for this build is a Raspberry Pi driving an LCD display recovered from an old iPad. There’s a custom TV tuner which handles changing the channels and interfaces with an Apple Remote. Audio is sent through old computer speakers, and the case is built from 3D printed parts and some leftover walnut plywood to give it an era-appropriate 80s or early 90s feel. We’ve seen other builds like this before, but where this one really sets itself apart is in the software that handles the (television) programming.

[Irish Craic Party] has gone to great lengths here to recreate the feel of cable TV from decades ago. It has recreations of real channels like HBO, Nickelodeon, and FX including station-appropriate bumpers and commercials. It’s also synchronized to the clock so shows start on the half- or quarter-hour. Cartoons play on Saturday morning, and Nickelodeon switches to Nick-at-Nite in the evenings. There are even channels that switch to playing Christmas movies at the appropriate times, complete with Christmas-themed commercials.

The build even hosts a preview channel, one of the more challenging parts of the build. It continually scrolls through the channels and shows what’s currently playing and what will be showing shortly, complete with a commercial block at the top. For those who were around in the 90s it’s almost a perfect recreation of the experience of watching TV back then. It can even switch to a video game input when tuned to channel 3. There’s almost too much to go into in a short write-up so be sure to check the video after the break.

Thanks to [PCrozier] for the tip!

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