MicroOS Is Immutable Linux

November 14, 2020 by Al Williams 41 Comments

Linux finds a lot of uses in computers that aren’t desktops. But there is a problem. What happens if your mission-critical control computer or retail kiosk gets an update and then fails? Happens all the time with Windows and it can happen with Linux, too. The openSUSE project has an answer: MicroOS which bills itself as immutable. Aimed at container deployment, the operating system promises atomic updates with no disk changes during runtime. If an update does break something, the BTRFS file system allows you to roll back to a previous snapshot. [Tyler] installs the OS and gives it a walkthrough in the video below.

As [Tyler] found, there are not many applications installed by default. Instead, you are expected to install flatpaks so the applications live in their own containers, isolated from the operating system and each other.

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What Is Worth Saving?

November 14, 2020 by Elliot Williams 72 Comments

When it rain, it pours. One of the primary support cables holding up the Arecibo Observatory dish in Puerto Rico has just snapped, leaving its already uncertain fate. It had been badly damaged by Hurricane Maria in 2017, and after a few years of fundraising, the repairs were just about to begin on fixing up that damage, when the cable broke. Because the remaining cables are now holding increased weight, humans aren’t allowed to work on the dome until the risk of catastrophic failure has been ruled out — they’re doing inspection by drone.

Arecibo Observatory has had quite a run. It started out life as part of a Cold War era ICBM-tracking radar, which explains why it can transmit as well as receive. And it was the largest transmitting dish the world had. It was used in SETI, provided the first clues of gravitational waves, and found the first repeating fast radio bursts. Its radar capabilities mean that it could be used in asteroid detection. There are a number of reasons, not the least of which its historic import, to keep it running.

So when we ran this story, many commenters, fearing the worst, wrote in with their condolences. But some wrote in with outrage at the possibility that it might not be repaired. The usual suspects popped up: failure to spend enough on science, or on infrastructure. From the sidelines, however, and probably until further structural studies are done, we have no idea how much a repair of Arecibo will cost. After that, we have to decide if it’s worth it.

Per a 2018 grant, the NSF was splitting the $20 M repair and maintenance bill with a consortium led by the University of Central Florida that will administer the site. With further damage, that might be an underestimate, but we don’t know how much of one yet.

When do you decide to pull the plug on something like this? Although the biggest, Arecibo isn’t the only transmitter out there. The next largest transmitters are part of Deep Space Network, though, and are busy keeping touch with spacecraft all around our solar system. For pure receiving, China’s FAST is bigger and better. And certainly, we’ve learned a lot about radio telescopes since Arecibo was designed.

I’m not saying that we won’t shed a tear if Arecibo doesn’t get repaired, but it’s not the case that the NSF’s budget has been hit dramatically, or that they’re unaware of the comparative value of various big-ticket astronomy projects. Without being in their shoes, and having read through the thousands of competing grant proposals, it’s hard to say that the money spent to prop up a 70 year old telescope wouldn’t be better spent on something else.

Turn-by-turn Smart Glasses Give You Direction

November 14, 2020 by Al Williams 22 Comments

[SamsonMarch] designs electronic products by day and — apparently — does it in his spare time, too. His latest is a pair of really cool shades that give him turn-by-turn directions as he walks around town. Unlike some smart glasses, these get around the difficult problem of building a heads-up display by using a very simple interface based on colored LEDs visible to your peripheral vision in the temples of the frames.

The glasses themselves look great; designed in Fusion 360 and cut out of wood, no one would give them a second glance. [Sam] says you could 3D print them, too, but we think the wood looks best even if the stock is a cheap bamboo cutting board. He also cut the lenses out of acrylic.

The slots in the temples are where the action is, though. An iPhone app takes input and talks to Apple services to get directions. A lot of thought went into making the app work even though the phone keeps trying to put it to sleep. Each PCB hosts an RGB LED for indicating left/right turn and destination. They talk to the app using BLE and include accelerometers which put the boards — powered by coin cells — into sleep mode when no movement is detected.

Overall a fun and good looking project. There are even covers to hide the boards during normal use. The files you need to reproduce it are on GitHub. Usually, when we see smart glasses, they have some sort of screen which is harder to do. Of course, it is impossible to avoid comparisons to Google Glass.

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Dremel 3D20 Printer Gets Modern Overhaul

November 14, 2020 by Tom Nardi 8 Comments

Dremel’s attempt at breaking into the 3D printer market back in 2014 was respectable, if not particularly exciting. Rather than design their own printer, their 3D20 “Idea Builder” was a lightly customized Flashforge Dreamer (itself a Makerbot Replicator clone) with a new warranty and support contract tacked on. It wasn’t necessarily the 3D printer of choice for the hacker and maker crowd, but it was a fairly solid option for folks who wanted a turn-key experience.

[Chris Chimienti] says he got about 1,000 hours of printing out of his 3D20 before it gave up the ghost. Given the age of the machine and its inherent limitations, he decided to use the Dremel’s carcass as the base for a very impressive custom 3D printer with all the modern bells and whistles. He kept the enclosure, rods, bearings, and the stepper motors, but pretty much everything else was tossed out. Some of the replacements are off-the-shelf parts, but it’s the custom designed elements on this build that really help set it apart.

A print bed strong enough to park your car on.

Under the machine, [Chris] has installed a new power supply and a Duet 2 WiFi controller which itself is connected to the new LCD control panel on the front. There’s an external case fan to keep the electronics cool, but otherwise things look a lot neater under the hood than they did originally.

Moving upwards, he’s designed a gorgeous adjustable print bed and a new extruder assembly that cleverly uses RJ45 jacks and Ethernet cables to connect back to the control board. All told, the custom components have taken this once relatively mid-range 3D printer and turned it into something that looks like it wouldn’t be out of place on the International Space Station.

While custom 3D printer builds like this still trickle in from time to time, we’re seeing far fewer now than we did back when machines like the 3D20 hit the market. Most people are more than satisfied with commercial entry-level desktop printers, and aren’t looking for yet another project to tinker with. There’s nothing wrong with that, though we certainly wouldn’t complain if the recent interest into more advanced high-temperature filaments triggered something of a bespoke 3D printer renaissance.

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Haunted TV Does Mirror Scares With Raspberry Pi

November 13, 2020 by Lewin Day No comments

Hallowe’en may be over for another year, but that just means you’ve got more time to prepare your build for next time. [gocivici] has a fun twist on the classic mirror scare that might be just up your alley.

The build starts with an old black and white TV, hooked up to a Raspberry Pi 3. The Pi films the scene in front of the television through a camera secreted into the screen’s headphone jack, and displays it on screen. The camera feed is run through OpenCV, which runs face and eye detection algorithms to determine when a person is looking at the screen. Based on a basic timer script, when a viewer has looked long enough, a ghostly apparition is displayed, lurking behind the viewer. When the user looks over their shoulder, the apparition quickly disappears, as per the classical horror trope.

It’s a fun build that would make an excellent set piece for your next Hallowe’en party. For extra effect, be sure to secret it down a dark hallway with some IR LEDs illuminating the scene for the camera only. If you prefer something with a little more whimsy, consider these animated singing pumpkins instead. Video after the break.

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Wireless Earphones And Getting Them Back After They Fall On Tram Tracks

November 13, 2020 by Maya Posch 34 Comments

Over the past years, the trend has become to ditch anything with wires. This has led to many people dropping wired earphones and headphones for wireless (Bluetooth) versions. Yet along with the freedom from having the wires snagged on something and having earphones painfully torn out of your ears comes the very real risk of having them drop out of your ears to land potentially very inconvenient.

In Japan this has led to a big issue for railway companies, where throngs of commuters will often accidentally drop possessions onto the tracks. Staff members will then use a mechanical claw (‘magic hand’) to fetch them without having to risk their life by jumping down. With small items such as wireless earphones, this is however not so easy. With 947 cases of dropped earphones in the period of July-September in just the Tokyo area, this has led to desperate staff members coming up with new methods of easily retrieving the small gadgets.

Solutions range from putting something sticky like tape at the end of a stick, to modifying vacuum cleaners. Most recently Tokyo railway company JR East has collaborated with Panasonic to develop a vacuum cleaner-like device that is especially designed to easily retrieve such small items from the tracks, according to the Japan Times article.

The embedded video (also found after the break) from a Japanese broadcaster describes the issue in detail, along with tips on how to properly wear earphones so that they’re far less likely to fall out when you’re waiting on the tram or walking down the street. While it’s possible to fetch your dropped wireless earphones from the tracks, having someone step on it right after it falls out of your ear on the street is less easy to recover from.

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Robotics Club Teaches Soldering

November 13, 2020 by Al Williams 25 Comments

Oregon State University must be a pretty good place to go to school if you want to hack on robots. Their robotics club, which looks active and impressive, has a multi-part video series on how to solder surface mount components that is worth watching. [Anthony] is the team lead for their Mars Rover team and he does the job with some pretty standard-looking tools.

The soldering station in use is a sub-$100 Aoyue with both a regular iron and hot air. There’s also a cheap USB microscope that looks like it has a screen, but is covered in blue tape to hold it to an optical microscope. So no exotic tools that you’d need a university affiliation to match.

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