Watch A Fast Sand Plotter Plow Patterns At Speed

September 22, 2020 by Donald Papp 21 Comments

[Mark]’s sand table wisely has a glass top.

Most of us have probably seen a video of a sand drawing table at work, in which a steel ball — magnetically-coupled to a gantry under a layer of sand — lazily draws geometric patterns with utter precision and zen-like calmness. That’s all well and good, but [Mark Rehorst] thinks it can also be interesting to crank up the speed and watch the ball plow through sand just as physics intended. There’s a deeper reason [Mark] is working at this, however. Faster drawing leads to less crisp results, but by how much, exactly? To answer this, [Mark] simply ran his table (which is named The Spice Must Flow) at both fast and slow speeds and documented the results.

These two images show the difference between running the table at 100 mm/s versus 500 mm/s. The slower speed is noticeably crisper, but on the other hand the faster speed completed the pattern in about a fifth of the time. [Mark] says that as the ball aggressively accelerates to reach target speeds, more sand is thrown around over existing lines, which leads to a loss of detail.

Crisper detail, or a faster draw? Which is “better” depends on many things, but it’s pretty clear that [Mark]’s cat finds the fast version more exciting. You can see [Mark]’s table at high speed and the cat’s reaction in the video, embedded below.

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SpaceX Sending Tom Cruise To The Space Station In 2021

September 22, 2020 by Tom Nardi 53 Comments

Several months after NASA Administrator Jim Bridenstine confirmed the project was in the works, sources are now reporting that Tom Cruise and director Doug Liman will officially be making the trip to the International Space Station in October of 2021 to film scenes for an as of yet untitled movie. Cruise and Liman previously worked together on the science fiction spectacle Edge of Tomorrow in 2014, which may give us a hint at what the duo are planning for their trip to the final frontier.

Industry insiders claim that the two film makers and potentially a female co-star will fly aboard a SpaceX Crew Dragon capsule under the command of Michael López-Alegría, a veteran astronaut who currently holds the American record for number and duration of extra-vehicular activities (EVAs). The mission is being organized by Axiom Space, which previously announced they would perform a series of privately funded flights to the ISS as a precursor to constructing their own commercial expansion to the orbiting laboratory.

Mars One living units under regolith — This never happened.

Of course, with more than a year before liftoff, anything could happen. SpaceX has been linked, officially or otherwise, to several private trips to space that literally and figuratively never got off the ground.

Mars-One was touting concept art that showed a fleet of modified SpaceX Dragons on the Red Planet as far back as 2012, and Elon Musk himself once announced that the Falcon Heavy would send private passengers on a trip around the Moon by the end of 2018. But to date, a pair of NASA astronauts have been the only humans to actually fly on SpaceX hardware.

Undoubtedly, some will see this flight of fancy as a waste of valuable resources. After all, there’s no shortage of scientists and researchers who would be more deserving of trip to a space than Jerry Maguire. But according to Bridenstine, the hope is that a big budget Hollywood film featuring scenes shot on the ISS could do for NASA what Top Gun once did for the Navy:

There was a day when I was in elementary school and I saw Top Gun. From that day, I knew I was going to be a Navy pilot. If we can get Tom Cruise to inspire an elementary kid to join the Navy and be a pilot, why can’t we get Tom Cruise to inspire the next Elon Musk? That’s what we need.

While we might not all agree on who the next generation of engineers should look to for inspiration, the impact that Top Gun had on Navy recruitment in the 80s and 90s is well established. If sending Tom Cruise to space for a few weeks might help inspire more kids to look into a STEM education, it’s probably worth a shot. Though it seems like Tom Hanks and his fellow Apollo 13 crew mates did a respectable enough job celebrating the incredible engineering behind NASA’s greatest triumph without actually going into orbit themselves.

Second-Hand Television SHINEs, Takes Down Entire Village’s Internet

September 22, 2020 by Dan Maloney 53 Comments

We occasionally get stories on the tips line that just make us want to know more. This is especially true with tech stories covered by the mass media, which usually leave out the juicy tidbits that would just clutter up the story for the majority of non-technical readers. That leaves us to dig a little deeper for the satisfying details.

The latest one of these gems to hit the tips line is the tale of a regular broadband outage in a Welsh village. As in, really regular — at 7:00 AM every day, the internet customers of Aberhosan suffered a loss of their internet service. Customers of Openreach, the connectivity arm of the British telco BT, complained about the interruptions as customers do, and technicians responded to investigate the issue. Nobody was able to find the root cause, and despite replacing nearly all the cables in the system, the daily outages persisted for 18 months.

In the end, Openreach brought in a crack team from their Chief Engineer’s office to investigate. Working against COVID-19 restrictions, the team set up a spectrum analyzer in the early morning hours, to capture any evidence of whatever was causing the problem. At the appointed hour they saw a smear of radio frequency interference appear, a high-intensity pulse of noise at just the right frequency to interfere with the village’s asymmetric digital subscriber line (ADSL) broadband service.

A little sleuthing led to the home of a villager and a second-hand TV, which was switched on every day at 7:00 AM. The TV was found to be emitting a strong RF impulse when it was powered up, strong enough to knock out the ADSL service to the entire village. Openreach categorized this as SHINE, or single high-level impulse noise. We’d never heard of this, but apparently it’s common enough that BT warns customers about it and provides helpful instructions for locating sources with an AM radio.

We’ll say one thing for the good people of Aberhosan: they must be patient in the extreme to put up with daily internet outages for 18 months. And it’s funny how there was no apparent notice paid by the offending television’s owner that his or her steady habit caused the outage. Perhaps they don’t have a broadband connection, and so wouldn’t have noticed the borking.

In any case, the owner was reportedly “mortified” by the news and hasn’t turned the TV on since learning of the issue. This generally seems to be the reaction when someone gets caught inadvertently messing up the spectrum — remember the Great Ohio Key Fob Mystery?

Thanks to [Kieran Donnelly] for spotting this for us.

Linkage Inferring Software Handwaves Away The Hard Stuff

September 22, 2020 by Sonya Vasquez 17 Comments

Jokes aside, manually designing linkages that move along specific paths is no easy task. Whether we’re doodling paper sketches or constraining lines in a CAD program, we still need to do the work of actually “imagining” the linkage design. If only there were some sort of tool that would do all that hard imagining work for us! Thankfully, we’re in luck! That’s exactly what researchers [Gen Nishida], [Adrien Bousseau2], and [Daniel G. Aliaga1] at Purdue have done. They’ve designed a software tool that lets us position important bodies in space in particular “key” frames, and then the software simply fills in the linkage for you!

To start the design process, the user inputs a few candidate locations that their solid bodies need to reach in the final linkage path. From here, these locations get fed to a particle filter. This particle filter seeds thousands of semi-random linkage configurations at small timesteps, selects some of the best-matching ones that most closely approximate the required body locations, removes the lesser-scoring results, re-creates a new set of possible joint configurations based on the best matching ones, and repeats until the tool converges on a linkage that respects our input key frames.

Like a brute force search, this solution takes lots and lots of samples to find a solution, but unlike a brute force search, trials iteratively improve, enabling the software to converge closer and closer to a final solution. Under the hood, the software needs to actually simulate these candidate linkage in order to grade them. It’s in this step that the team wrote in additional checks to remove impossible linkages like self-intersecting joints from this linkage “gene pool” before reseeding them. The result is a tool that does all that trial-and-error scratchwork for you–no brain cycles. For more details, have a peek at their (open access!) paper.

Design software that augments our mechanical design capabilities is a rare gem on these pages, and this one is no exception. If your curious to play with other useful linkages simulating tools, have a go at Linkage Designer. And if you’re in the mood for other tools that fill in the blanks, check out this machine learning algorithm that literally fills in footage between frames in a video feed.

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Inputs Of Interest: BIGtrack Mouse Might Make You Squeal

September 22, 2020 by Kristina Panos 20 Comments

You know me, I like to get my feet involved when I use my computer, which happens pretty much all day every day at this point. My cache of pedal inputs keeps growing like mushrooms in the darkness under my desk: every upper case letter in this post and dozens more have been capitalized with a shift pedal!

Naturally, I’ve thought about what it might be like to mouse with my toes. The more time I can spend with both hands on the keyboard, the better. I started sniffing around for foot-sized trackball candidates, thinking maybe I could just build one with regular mouse guts. Then I found a 15-year-old Golden Tee home edition console at a thrift store. It has a large ball and four buttons, so it seemed ripe for turning into a mouse as-is, or just stealing the ball to build my own. So far, that hasn’t happened, though I did solder a bunch of wires for testing out the controls. Continue reading “Inputs Of Interest: BIGtrack Mouse Might Make You Squeal” →

A Digital Guestbook Is A Perfect Hacker Wedding Gift

September 22, 2020 by Lewin Day 2 Comments

With his brother’s wedding coming up, [Sebastian] needed a wedding gift. Rather than purchasing something, he elected to build a digital guestbook so guests could share their well-wishes with the happy couple.

The guestbook has a simple web-based interface, which was accessible over a domain name [Sebastian] registered with the couple’s names ahead of the event. There, users could enter text and draw a friendly message for the digital guestbook. The guestbook itself consists of an ESP32 running a e-ink display, packaged in a tidy 3D printed enclosure featuring the couple’s initials. It regularly queries the web server, and displays the messages it finds on the screen.

It’s a great use of an e-ink display, as it made reading the messages in bright daylight easy where other technologies may have faltered. [Sebastian] was also clever to install some LEDs for the night portion of the reception. We’ve featured a few wedding gifts on these pages before, including this particularly amusing sugar cube. Video after the break.

Continue reading “A Digital Guestbook Is A Perfect Hacker Wedding Gift” →

Remoticon Tickets And Workshops Just Dropped

September 22, 2020 by Mike Szczys 9 Comments

Hackaday Remoticon happens November 6-8 worldwide! The weekend will be packed with virtual activities, and most of them are hands-on workshops that you can participate in from the comfort of your home, lab, garage, basement, lair, or other socially distanced location of your choosing.

The news today is that everyone should register for Remoticon right now, and that we’re opening up registration for about half of the total workshops. More details on the remaining workshops, demos, and some special events will be available in a future article.

Get a Ticket for Remoticon, Then Register for Workshops

Step 1: Register for the Con. What you want to do right now is head over to the Remoticon ticketing page and register for the conference. We need to get a headcount so that our servers don’t melt down during this massive online social event. You can get a ticket for free, or you can choose pay as you wish — scroll to the bottom of the tickets under “Donations” — and those proceeds go to charities that feed, house, or educate people. In these hard times, if you’re in a position to spare a few bucks, please do so.

Step 2: Buy your workshop ticket(s). A workshop isn’t a workshop unless you can ask questions and get help along the way. Workshop tickets are for attendees who want to participate live, interacting with the presenters and other attendees via video chat. We’ve made all workshop tickets $10 as “skin in the game” to help ensure that these limited slots go to good use. Proceeds from workshop tickets will be used to offset the costs of hosting Remoticon.

If there is one request that we get every Supercon, it’s to film the workshops. This year, we can! If you can’t attend a workshop that you’re interested in we plan to record, edit, and publish them all so everyone can follow along at a later date.

The registration page has workshop descriptions listed when you select your ticket, but here are the titles whet your appetite. Thank you to everyone who submitted a workshop proposal, none of this is possible without you, naturally.