A heat wave spreading across a large portion of the west coast of the United States is not surprising for this time of year, but the frequency and severity of these heat waves have been getting worse in recent years as the side effects from climate change become more obvious. In response to this, the grid operators in California have instituted limited rolling blackouts as electricity demand ramps up.
This isn’t California’s first run-in with elective blackouts, either. The electrical grid in California is particularly prone to issues like this, both from engineering issues and from other less obvious problems as well.
Conductive filament isn’t an ideal electrical conductor, but it’s a 3D-printable one and that’s what makes [Hercemer]’s 3D-printed flashlight using conductive filament work. Every part of the flashlight is printed except for the 9 volt battery and LEDs. Electrically speaking, the flashlight is a small number of LEDs connected in parallel to the terminals of the battery, and turning it on or off is done by twisting or loosening a cap to make or break the connection.
The main part of the build is a 3D-printed conductive cylinder surrounded by a printed conductive ring with an insulator between them. This disk- or pad-shaped assembly forms not only the electrical connection between the LEDs and battery terminals, but also physically holds the LEDs. To attach them, [Hercemer] simply melts them right in. He uses a soldering iron to heat up the leads, and presses them into the 3D-printed conductive block while hot. The 9 V battery’s terminals contact the bottom when the end cap is twisted, and when they touch the conductive assembly the flashlight turns on.
Anode of each LED goes to the center, cathodes to the outside ring.
LED leads are melted-in with a soldering iron.
9 V battery pressed to the bottom of the conductive block lights up the LEDs.
Anticipating everyone’s curiosity, [Hercemer] measured the resistance of his conductive block and measured roughly 350 ohms when printed at 90% infill; lower infills result in more resistance. You can see a video of the assembly and watch the flashlight in action in the video, embedded below.
Coroutines in Kotlin are a way to simplify writing asynchronous code, which is code that doesn’t necessarily execute in the order it is written. Coroutines are like light-weight threads that can be launched and managed easily, making it simpler to bridge together blocking and non-blocking code. (However, coroutines are not threads. They are more akin to suspending functions that play very well together.)
[Foalyy] found that the official Kotlin documentation on coroutines went into great detail on how coroutines function, but wanted a more bottom-up approach to understanding how they work and can be used. Luckily for anyone who thinks the same way, [Foalyy] wrote it all up and begins with a great recap of important elements, but if you prefer you can jump straight to the examples.
As we stare dejectedly at our screens and consider what might have been during the 2020 summer that didn’t quite happen, here’s a little something to look forward to in a future where the COVID-19 pandemic will with any luck be much less of a threat. We have have had precious little in the way of events in 2020, but the call for participation has been announced for one of the largest planned for 2021. MCH2021 will be big European summer camp of next year, and is scheduled for the 6th to the 10th of August at Scoutinglandgoed Zeewolde in the Netherlands province of Flevoland. It will be the latest in a long line of such events going back to 1989, and with such a track record we know it’s going to be a good one.
We know that among our community are many people who’ll be interested in going to MCH, and that each and every one of you will have some fascinating insights that others would love to hear about. The challenge of the MCH orga is to bestow upon you the courage to stand up in front of your peers and talk about it, and from our experience here at Hackaday we’d say that an event such as this one makes for a very good place to give speaking a try. As always they’re interested in all the cool stuff that comes from our diverse community, but to help you along they’ve suggested a theme. Recent events have it’s fair to say presented a challenge to the world, and in that light they state that “we are especially looking for content that is about our ability to recover from extreme events of whatever nature”. We look forward to seeing you there.
Press that blue button on the side, and the RGB LEDs along the top are put in randomized order. The object of this game is simple — just sort the rainbow before the other player by pressing each LED’s corresponding arcade button. Whoever sorts faster is rewarded with a rainbow animation behind their set of way-cool clear buttons.
Inside the laser-cut box is an Espruino, which is a handy little microcontroller that speaks JavaScript. All of the arcade buttons are wired up as a key matrix. The astute among you have noticed there is six of everything, and that’s because indigo light is too hard to distinguish from blue. Check out the intense gameplay after the break.
Tech history is rife with examples of bizarre product demos, but we’ve got to think that Elon Musk’s Neuralink demo this week will have to rank up there with the weirdest of them. Elon’s job here was to sell the proposition that having a quarter-sized plug removed from your skull by a surgical robot and having it plunge 1,024 tiny wires into your gray matter will be totally normal and something that all the cool kids will be doing someday. We watched the 14-minute supercut of the demo, which went on for considerably longer than that due to the realities of pig wrangling, and we remain unsold on the technology. Elon selling it as “a Fitbit in your skull, with tiny wires” probably didn’t help, nor did the somewhat terrifying appearance of the surgical robot needed to do the job. On the other hand, Gertrude the Bionic Pig seemed none the worse for her implant, which was reportedly wired to her snout and sending data wirelessly. The demonstration of reading joint positions directly from the brain was honestly pretty neat. If you want to dive deeper into Neuralink, check out Maya’s great article that separates fact from science fiction.
Jerry Carr, NASA astronaut and commander of the third and final crewed Skylab mission, passed away this week at the age of 88. Carr’s Skylab 4 mission was record-breaking in 1974, with the three astronauts living and working in the orbiting workshop for 84 days. The mission contributed a vast amount of information on space medicine and the human factors of long-duration spaceflight. Carr retired from NASA in 1977 and had a long career as an engineer and entrepreneur. It’s sad to lose yet another of the dwindling number of heroes remaining from NASA’s manned-flight heyday.
Speaking of spaceflight, the closest most of us DIYers can get to space is likely courtesy of a helium-filled balloon. If you’ve ever considered sending something — or someone — aloft, you’ll find this helium balloon calculator an invaluable tool. Just plug in the weight of your payload, select from a few common balloon sizes, and the calculator will tell you how many you need and how much gas it will take to fill them. It’s got a second section that tells you how many more balloons it’ll take to get to a certain altitude, should merely getting off the ground not be enough for you.
If 2020 has proven anything, it’s that time is, at best, a negotiable concept. Improbably, September is only a day away, after an August that somehow took forever to go by in the blink of an eye. With that in mind, October is OSHWA’s Open Hardware Month, with this year’s theme being “Label and Certify”. We’re a little bit in love with the Open Hardware Facts generator, which takes your open-source hardware, software, and documentation license and generates a USDA “Nutrition Facts”-style label for your product. They’ve also added tools to make it easier to get OSHWA certification for your project.
And finally, what would it be like to pilot a giant exoskeleton? Like, a 9,000 pound (4,100 kg), quadrupedal all-terrain beast of a mech? Turns out you can (theoretically) find out for yourself courtesy of Furrion Exo-Bionics and their monster mech, dubbed Prosthesis. The machine has been in development for a long time, with the vision of turning mech racing into the next big thing in sports entertainment. Their Alpha Mech Pilot Training Program will allow mere mortals to learn how to pilot Prosthesis at the company’s proving ground in British Columbia. Details are sparse, so caveat emptor, but it sure looks like fun.
They say that imitation is the sincerest form of flattery. If we were going to imitate one of master circuit sculptor Mohite Bhoite’s creations, we’d probably pick the little blinky solar satellite as a jumping off point just like [richardsappia] did. It’s cute, it’s functional, and it involves solar power and supercapacitors. What more could you want?
SATtiny is a pummer, which is BEAM robotics speak for a bot that soaks up the sun all day and blinks (or ‘pumms’, we suppose) for as long as it can throughout the night on the juice it collected. This one uses four mini solar panels to charge up a 4 F supercapacitor.
At the controls is an ATtiny25V, which checks every eight seconds to see if the supercapacitor is charging or not as long as there is enough light. Once night has fallen, the two red LEDs will pumm like a pair of chums until the power runs out. Check out the brief demo after the break.
