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304 Articles

Great Beginnings: The Antikythera Mechanism Gets A “Day Zero”

April 14, 2022 by 29 Comments

When an unknown genius sat down more than 2,000 years ago to design and build an astronomical instrument, chances are good that he or she didn’t think that entire academic institutions devoted to solving its mysteries would one day be established. But such is the enduring nature of the Antikythera mechanism, the gift from antiquity that keeps on giving long after being dredged up from a shipwreck in the Aegean Sea.

And now, new research on the ancient mechanism reveals that like other mechanical calendars, the Antikythera mechanism has a “day zero,” or a minimum possible date that it can display. The analysis by a team led by [Aristeidis Voulgaris] gets deep into the weeds of astronomical cycles, which the mechanism was designed to simulate using up to 37 separate gears, 30 of which have been found. The cycle of concern is the saros, a 223 lunar month cycle of alignments between the Earth, Sun, and Moon. The saros can be used to predict eclipses, astronomical events of immense importance in antiquity, particularly annular eclipses, which occur when the Moon is at apogee and therefore eclipses less of the Sun’s surface.

The researchers looked at historical annular eclipse data and found that saros cycle 58 had a particularly long annular eclipse, on 23 December 178 BCE. The eclipse would have been visible at sunrise in the eastern Mediterranean, and coupled with other astronomical goodies, like the proximity to the winter solstice, the Sun entering Capricorn, and the Moon being new and at apogee, was probably so culturally significant to the builder that it could serve as the initial date for calibrating all the mechanisms pointers and dials.

Others differ with that take, of course, saying that the evidence points even further back, to a start date in the summer of 204 BCE. In any case, if like us you can’t get enough Antikythera, be sure to check out our overview of the mechanism, plus [Clickspring]’s exploration of methods perhaps used to build it.

Hackaday Prize 2022: Solar Harvesting Is Better With Big Capacitors

March 30, 2022 by 26 Comments

The sun is a great source of energy, delivering in the realm of 1000 watts per square meter on a nice clear day. [Jasper Sikken] has developed many projects that take advantage of this power over the years, and has just completed his latest solar harvesting module for powering microcontroller projects.

The concept is simple. A small solar panel is used to charge up a lithium ion capacitor (LIC), which can then be used to power other projects. We first saw this project last year, when it was one of the winners of Hackaday’s 2021 Earth Day contest. Back then, it was only capable of dishing out 80 mA at 2.2V.

However, the latest version ups the ante considerably, delivering up to 400 mA at 3.3V. This opens up new possibilities, allowing the module to power projects using technologies like Bluetooth, WiFi and LTE that require more current to operate. It relies on a giant 250 F capacitor to store energy, and a AEM10941 solar energy harvesting chip to get the most energy possible out of a panel using Maximum Power Point Tracking (MPPT).

It’s a useful thing to have for projects that you’d like to run off the sun, and you can score one off Tindie if you don’t want to build your own. We’ve seen [Jasper] pull off other neat solar-powered projects before, too. Video after the break.

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Pedal Powered Power

March 14, 2022 by 19 Comments

When you have a solar-powered web server, where do you go next for a source of power? Instead of lazily mooching off the sun, you can use your muscle with a bike generator. [Ed note: The site is run on an entirely solar-powered server, so if it’s the middle of the night, you might have a better web experience here.]

We’ve covered bicycle generators before, so what’s new? For starters, the accessibility of chargers and batteries has changed significantly. Rather than just charging a phone or putting out a measly 5V, this bike can be integrated into an existing solar PV system and output many voltages. This guide goes over building one with hand tools with great detail.

It starts with a 1950’s vintage exercise bicycle, no hacksaw required. A friction drive connects a generator and makes for an incredibly compact generator/exercise machine. Calculating the correct gear ratio is crucial to getting the 12 volts out at an average pedaling speed. You want your range of voltages to be between 5 and 24 volts. With the help of a control panel provides 5v, 12v, 14.4v, and 220v to power a variety of devices. Boost and buck converters output these voltages (depending on whether the voltage needs to be set for a maximum or a minimum). A potentiometer allows you to dial back the power draw of certain appliances (an electric kettle, for instance), making a workout a tad easier on the human component of the generator.

Another key takeaway from this guide is using a wind charge controller to charge batteries. A solar charge controller will just cut the circuit when the batteries are full. A wind charge controller will increase the load until the motor breaks. Some controllers are also hybrid wind and solar, allowing you to connect a small panel like the one running the webserver this guide is posted on and then charge up the batteries when it has been overcast for a few days in a row.

the algae panel

Move Aside Solar, We’re Installing An Algae Panel

February 7, 2022 by 58 Comments

[Cody] of Cody’sLab has been bit by what he describes as the algae growing bug. We at Hackaday didn’t know that was a disease floating around, but we’ll admit that we’re not surprised after the last few years. So not content to stick to the small-time algae farms, [Cody] decided to scale up and build a whole algae panel.

Now, why would you want to grow algae? There are edible varieties of algae, you can extract oils from it, and most importantly, it can be pumped around in liquid form. To top it off, all it needs is just sunlight, carbon dioxide, and a few minerals to grow. Unlike those other complicated land-based organisms that use photosynthesis, algae don’t need to build any structure to hold themselves up or collect sunlight; it floats.

The real goal of the algae is to build a system known as “Chicken Hole.” The basic idea is to have a self-sufficient system. The algae feed the insects, the insects feed the chickens, and so on up the chain until it reaches [Cody]. While glass would make an ideal material for the algae tubes, plastic soda bottles seem like a decent proxy for a prototype and are much cheaper. He connected around 100 half-liter bottles to form long tubes and a PVC distribution system. The algae needs to be pumped into an insulated container to prevent it from freezing at night. At first, a simple timer outlet controlled the pump to only run during the day, draining it via gravity at night. However, the algae can’t heat up enough when running on cloudy, cold winter days, and it cools off. A solar panel and a temperature sensor form the logic for the pump, with a minimum temperature and sunlight needed to run.

[Cody] mentions that he can expect around 10 grams of algae per day on a panel this size in the winter. He’s going to need quite a few more if he’s going to scale up properly. Perhaps in the future, we’ll see panels growing algae robots? Video after the break.

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Floating Solar Farms Are Taking The World’s Reservoirs By Storm

January 24, 2022 by 60 Comments

Photovoltaic solar panels are wonderful things, capable of capturing mere light and turning it into useful electricity. They’re often installed on residential and commercial rooftops for offsetting energy use at the source.

However, for grid-scale generation, they’re usually deployed in huge farms on tracts of land in areas that receive plenty of direct sunlight. These requirements can often put solar farms in conflict with farm-farms — the sunlight that is good for solar panels is also good for growing plants, specifically those we grow for food.

One of the more interesting ideas, however, is to create solar arrays that float on water. Unlike some of the wackier ideas out there, this one comes with some genuinely interesting engineering benefits, too!

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Hackaday Links: November 7, 2021

November 7, 2021 by 3 Comments

More trouble for Hubble this week as the space observatory’s scientific instruments package entered safe mode again. The problems started back on October 25, when the Scientific Instrument Command and Data Handling Unit, or SI C&DH, detect a lack of synchronization messages from the scientific instruments — basically, the cameras and spectrometers that sit at the focus of the telescope. The issue appears to be different from the “payload computer glitch” that was so widely reported back in the summer, but does seem to involve hardware on the SI C&DH. Mission controller took an interesting approach to diagnosing the problem: the dusted off the NICMOS, or Near Infrared Camera and Multi-Object Spectrometer, an instrument that hasn’t been used since 1998. Putting NICMOS back into the loop allowed them to test for loss of synchronization messages without risking the other active instruments. In true hacker fashion, it looks like the fix will be to change the software to deal with the loss of sync messages. We’ll keep you posted.

What happened to the good old days, when truck hijackings were for things like cigarettes and booze? Now it’s graphics cards, at least according to a forum post that announced the theft of a shipment of EVGA GeForce RTX 30-series graphics cards from a delivery truck. The truck was moving the cards from San Francisco to the company’s southern California distribution center. No word as to the modus operandi of the thieves, so it’s not clear if the whole truck was stolen or if the cards “fell off the back.” Either way, EVGA took pains to note that receiving stolen goods is a crime under California law, and that warranties for the stolen cards will not be honored. Given the purpose these cards will likely be used for, we doubt that either of these facts matters much to the thieves.

Remember “Jet Pack Man”? We sure do, from a series of reports by pilots approaching Los Angeles International airport stretching back into 2020 and popping up occasionally. The reports were all similar — an object approximately the size and shape of a human, floating aloft near LAX. Sightings persisted, investigations were launched, but nobody appeared to know where Jet Pack Man came from or what he was flying. But now it appears that the Los Angeles Police may have identified the culprit: one Jack Skellington, whose street name is the Pumpkin King. Or at least a helium balloon version of the gangly creature, which is sure what an LAPD helicopter seems to have captured on video. But color us skeptical here; after all, they spotted the Halloween-themed balloon around the holiday, and it’s pretty easy to imagine that the hapless hero of Halloween Town floated away from someone’s front porch. More to the point, video that was captured at the end of 2020 doesn’t look anything like a Skellington balloon. So much for “case closed.”

Speaking of balloons, here’s perhaps a more productive use for them — lifting a solar observatory up above most of the atmosphere. The Sunrise Solar Observatory is designed to be lifted to about 37 km by a balloon, far enough above the Earth’s ozone layer to allow detailed observation of the Sun’s corona and lower atmosphere down into the UV range of the spectrum. Sunrise has already flown two successful missions in 2009 and 2013 which have netted over 100 scientific papers. The telescope has a one-meter aperture and automatic alignment and stabilization systems to keep it pointed the right way. Sunrise III is scheduled to launch in June 2022, and aims to study the flow of material in the solar atmosphere with an eye to understanding the nature of the Sun’s magnetic field.

And finally, what a difference a few feet can make. Some future Starlink customers are fuming after updating the location on their request for service, only to find the estimated delivery date pushed back a couple of years. Signing up for Starlink satellite service entails dropping a pin on a map to indicate your intended service location, but when Starlink put a new, more precise mapping app on the site, some eager pre-order customers updated their location to more accurately reflect where the dish will be installed. It’s not clear if the actual location of the dish is causing the change in the delivery date, or if just the act of updating an order places you at the bottom of the queue. But the lesson here may be that with geolocation, close enough is close enough.

Quint explaining his water turbine

Power Your Home With A Water Battery

October 8, 2021 by 69 Comments

I’ve stated it before on Hackaday but one of the most interesting engineering challenges posed to me this year was “how could you store enough energy to power a decent portion of a home for several hours without using batteries, all while staying within the size of a typical suburban plot?” [Quint Builds] attempts something up that alley by using solar power to pump water up onto his roof and later releasing it for power generation. (Video, embedded below.)

Earlier [Quint] had built a water collecting system using his gutters and a bell siphon but wasn’t satisfied with the overall power output. Using the turbine he had created for that system, he put a 55-gallon drum on top of his roof with the help of some supporting structures. We’d like to advise the public to consult a professional before adding a large heavy weight on top of your roof, but [Quint] forges ahead after studying his trusses and determining it to be a risk he is willing to take. A solar panel runs a small pump that pumps water from a reservoir up to the top of the roof when the sun shines with a float switch in the roof barrel stopping the motor once it’s full. A valve at the bottom allows water to spin the turbine and fill back into the bottom reservoir, forming a closed loop. There were a few snags along the way with prototype circuits not being fully contacted and the motor needing water cooling, an issue fixed by a custom CNC’d heat sink. The fixes for the various issues are almost as entertaining to see as the actual system itself.

It’s incredible to see lights come on powered by water alone but also sobering to realize just how much water you’d need to power a typical home. Perhaps if [Quint] upgrades, he can swap out the small motor for a larger 3D printed water pump.

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