Heating A Home With Sunlight… And Water

April 22, 2021 by Bryan Cockfield 64 Comments

The sun is a tremendous source of energy, and while photovoltaic panels are an easy way to harvest some of that energy especially now that prices for them are incredibly low, there are plenty of other ways to tap into that free energy as well. [Engelbert] was looking for alternative ways to heat his house since traditional methods were prohibitively expensive, and ended up building a heat exchanger using solar-heated water to cover his home heating needs. (Google Translate from Dutch)

The system uses several large roof-mounted hot water heating panels. The heat captured by them is then pumped into an underground pipe network which is able to warm up a large area of earth in the summer. In the winter, that heat is able to be extracted back out of the earth and used to heat his home. The system includes almost three kilometers of pipe which are buried two meters below grade, so this will probably not be a weekend project, but it still cost much less than the €80,000 to install gas heating in his home.

[Engelbert] is able to use this self-built system to keep his home and another smaller building at a constant 23°C all year. He actually overbuilt the system slightly and has since disconnected almost half of the pipes, but we certainly understand the desire to over-engineer things around here. The only problem he has had is with various government entities that are slow to adopt energy-efficient systems like these. Perhaps the Dutch government can take some notes from the Swiss when it comes to installing geothermal systems like these.

Thanks to [Jero] for the tip!

Antique Map Of Paris With Modern Tech

April 10, 2021 by Bryan Cockfield 7 Comments

There’s plenty to love about antiques, from cars, furniture, to art. While it might be a little bit of survivorship bias, it’s easy to appreciate these older things for superior quality materials, craftsmanship, or even simplicity. They are missing out on all of our modern technology, though, so performing “restomods” on classics is a popular activity nowadays. This antique map of Paris, for example, is made of a beautiful hardwood but has been enhanced by some modern amenities as well.

At first the creator of this project, [Marc], just wanted to give it some ambient lighting, but it eventually progressed over the course of two years to have a series of Neopixels hidden behind it that illuminate according to the current sun and moon positions. The Neopixels get their instructions from an ESP8266 which calculates these positions using code [Marc] wrote himself based on the current date. Due to the limitations of the ESP8266 it’s not particularly precise, but it gets the job done to great effect.

To improve on the accuracy, [Marc] notes that an ESP32 could be used instead, but we can give the ESP8266 a pass for now since the whole project is an excellent art installation even if it is slightly off on its calculations. If you need higher accuracy for tracking celestial objects, you can always grab a Raspberry Pi too.

Increasing The Resolution Of The Electrical Grid

February 24, 2021 by Matthew Carlson 68 Comments

As a society in the USA and other parts of the world, we don’t give much thought to the twisting vines of civilization that entangle our skies and snake beneath our streets. The humming electrical lines on long poles that string our nations together are simply just there. Ever-present and immutable. We expect to flick the switch and power to come on. We only notice the electrical grid when something goes wrong and there is a seemingly myriad number of ways for things to go wrong. Lighting strikes, trees falling on lines, fires, or even too many people trying to crank on the A/C can all cause rolling blackouts. Or as we found out this month, cold weather can take down generation systems that have not been weatherized.

We often hear the electrical grid described as aging and strained. As we look to the future and at the ever-growing pressure on the infrastructure we take for granted, what does the future of the electrical grid look like? Can we move past blackouts and high voltage lines that criss-cross the country?

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Solar Safety Bag Lights Up The Night, Charges Your Phone

January 18, 2021 by Kristina Panos 15 Comments

Spend enough time riding a bike, and chances are good that you’ll start carrying a few tools with you. Even if you don’t, you’re probably going to use a bag to carry something along, so why not make that bag do triple duty? This convertible backpack/tote bag can charge your phone and provide safety lighting for nighttime rides. The design lends itself nicely to turn signals, too.

This bag was designed to show off the capabilities of Loomia, a line of prototyping parts made with e-textiles and other flexible applications in mind. It can be sewn, fused, or adhered to various substrates including fabric and wood. [AmpedAtelier] is using a Beetle microcontroller to control RGB LED strips using an illuminated Loomia soft switch on the strap. The switch is wired to the microcontroller through Loomia busses running through the strap.

Although Loomia’s site has a deep dive into the capabilities of their technology, it isn’t exactly open source. If that’s what you’re after, take a look at PolySense, which uses piezoresistive dye to create textile sensors.

World Solar Challenge: How Far In A Solar Car?

December 21, 2020 by Lewin Day 90 Comments

Solar power is a great source of renewable energy, but has always had its limitations. At best, there’s only 1,000 Watts/m² available at the Earth’s surface on a sunny day, and the limited efficiency of solar panels cuts this down further. It’s such a low amount that solar panels on passenger cars have been limited to menial tasks such as battery tending and running low-power ventilation fans.

However, where some might see an impossibility, others see opportunity. The World Solar Challenge is a competition that has aimed to show the true potential of solar powered transport. Now 30 years since its inception, what used to be impossible is in fact achieved by multiple teams in under one tenth of the original time. To keep competitors on their toes, the rules have been evolving over time, always pushing the boundaries of what’s possible simply with sunlight. This isn’t mainstream transportation; this is an engineering challenge. How far can you go in a solar car?

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Hackaday Links: December 13, 2020

December 13, 2020 by Dan Maloney 16 Comments

Our Sun is getting a bit frisky these days, and has rewarded us with perhaps the best screensaver image ever taken. The incredibly detailed photo of a sunspot was actually taken back in January by the Daniel K. Inouye Solar Telescope, a 4-meter instrument with adaptive optics that can image the sun from the near-infrared to visible wavelengths and resolve surface details down to 20 km. The photo, with a distinct “Eye of Sauron” look, shows the massive convection cells surrounding the dark sunspot; an accompanying animation shows the movement of plasmas along the tortured lines of magnetic flux that cause the sunspot to form. It’s fascinating to watch, and even more interesting to mull over the technology that went into capturing it.

With the dustup surrounding the youtube-dl DCMA takedown by GitHub fresh on the open-source community’s minds, GitHub Universe 2020 had an interesting discussion about maintaining open-source software projects that’s worth watching. They focused on the challenges that youtube-dl maintainers face in keeping the tool working, and the impact their effort has on the people and groups that rely on them. To underscore that point, they featured a researcher with Human Rights Watch who depends on youtube-dl in her work, and made it quite clear that keeping up with all the API changes that constantly break open source tools like youtube-dl make the role of the maintainers that much more critical.

Speaking of GitHub, here’s a frightening and fascinating new tool: Depix, the password de-pixelizer. Developer Sipke Mellema noticed that his company often used pixelization to obscure passwords in documentation, and wondered if he could undo the process. He wrote up an article describing the pixelization process using a linear box filter and his method for attacking it, which involves generating a De Bruijn sequence in the same font, text size, and colors as the original document and feeding a screenshot of that and the pixellated password into the tool. We suspect it’ll only work for a subset of obfuscated passwords, but it’s still pretty clever.

‘Tis the season for Advent calendars, and the folks at QEMU have posted theirs. Open each of 24 doors on the calendar and you’re rewarded with a downloadable QEMU disk image that implements something fun. Minesweeper, a ray tracer that fits into a boot loader, and of course Conway’s Game of Life. The GW-BASIC image on Day 3 caught our eye — brings back some memories.

For anyone who has ever watched a Pixar film and wondered how all that animation actually works, here’s a great lesson in making art with math. The video is by Inigo Quilez and goes through the basics of rendering images using raymarching SDFs, or signed distance functions. In the beginning, it seemed like it was going to be a little bit like drawing an owl, but his descriptions of the math involved and how each element of the animation is just another formula is fascinating. What’s more, there’s a real-time rendering tool where you can inspect the code and edit it. Alas, my changes only made things worse, but it was still fun and instructive to play with. Check out the video after the break!

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Hacker’s Discovery Changes Understanding Of The Antikythera Mechanism

December 12, 2020 by Dan Maloney 46 Comments

With all the trained academics who have pored over the Antikythera mechanism in the 120 years since it was pulled from the Mediterranean Sea, you’d think all of the features of the ancient analog computer would have been discovered by now. But the mechanism still holds secrets, some of which can only be appreciated by someone in tune with the original maker of the device. At least that what appears to have happened with the recent discovery of a hitherto unknown lunar calendar in the Antikythera mechanism. (Video, embedded below.)

The Antikythera mechanism is fascinating in its own right, but the real treat here is that this discovery comes from one of our own community — [Chris] at Clickspring, maker of amazing clocks and other mechanical works of art. When he undertook a reproduction of the Antikythera mechanism using nothing but period-correct materials and tools four years ago, he had no idea that the effort would take the direction it has. The video below — also on Vimeo — sums up the serendipitous discovery, which is based on the unusual number of divisions etched into one of the rings of the mechanisms. Scholars had dismissed this as a mistake, but having walked a mile in the shoes of the mechanism’s creator, [Chris] knew better.

The craftsmanship and ingenuity evidenced in the original led [Chris] and his collaborators to the conclusion that the calendar ring is actually a 354-day calendar that reflects a lunar cycle rather than a solar cycle. The findings are summarized in a scholarly paper in the Horological Journal. Getting a paper accepted in a peer-reviewed journal is no mean feat, so hats off to the authors for not only finding this long-lost feature of the Antikythera mechanism and figuring out its significance, but also for persisting through the writing and publication process while putting other projects on hold. Clickspring fans have extra reason to rejoice, too — more videos are now on the way!

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