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3D Printed Stethoscope Makes the Grade

Hackaday - 2 hours 19 minก่อน

On the off chance that initiatives like the Hackaday Prize didn’t make it abundantly clear, we believe strongly that open designs can change the world. Putting technology into the hands of the people is a very powerful thing, and depending on where you are or your station in life, can quite literally mean the difference between life and death. So when we saw that not only had a team of researchers developed a 3D printable stethoscope, but released everything as open source on GitHub, it’s fair to say we were pretty interested.

The stethoscope has been in development for several years now, but has just recently completed a round of testing that clinically validated its performance against premium brand models. Not only does this 3D printed stethoscope work, it works well: tests showed its acoustic performance to be on par with the gold standard in medical stethoscopes, the Littmann Cardiology III. Not bad for something the researchers estimate can be manufactured for as little as $3 each.

All of the 3D printed parts were designed in OpenSCAD (in addition to a Ruby framework called CrystalSCAD), which means the design can be evaluated, modified, and compiled into STLs with completely free and open source tools. A huge advantage for underfunded institutions, and in many ways the benchmark by which other open source 3D-printable projects should be measured. As for the non-printed parts, there’s a complete Bill of Materials which even includes links to where you can purchase each item.

The documentation for the project is also exceptional. It not only breaks down exactly how to print and assemble the stethoscope, it even includes multi-lingual instructions which can be printed out and distributed with kits so they can be assembled in the field by those who need them most.

From low-cost ultrasounds to truly personalized prosthetics, the future of open source medical devices is looking exceptionally bright.

[Thanks to Qes for the tip]

Balloons and Bubbles Make for Kid-Friendly Robot Deathmatch

Hackaday - 5 hours 19 minก่อน

Because nothing says “fun for kids” like barbed wire and hypodermic needles, here’s an interactive real-world game that everyone can enjoy. Think of it as a kinder, gentler version of Robot Wars, where the object of the game is to pop the balloon on the other player’s robot before yours get popped. Sounds simple, but the simple games are often the most engaging, and that sure seems to be the case here.

The current incarnation of “Bubble Blast” stems from a project [Niklas Roy] undertook for a festival in Tunisia in 2017. That first version used heavily hacked toy RC cars controlled with arcade joysticks. It was a big hit with the crowd, so [Niklas] built a second version for another festival, and incorporated lessons learned from version 1.0. The new robots are built from scratch from 3D-printed parts. Two motors drive each bot, with remote control provided by a 433-MHz transceiver module. The UI was greatly improved with big trackballs, also scratch built. The game field was expanded and extra obstacles were added, including a barbed wire border as a hazard to the festooned bots. And just for fun, [Niklas] added a bubble machine, also built from scratch.

The game looks like a ton of fun, and seems like one of those things you’ve got to shoo the adults away from so the kids can enjoy it too. But if you need more gore from your robot deathmatch than a limp balloon, here’s a tabletop robot war that’s sure to please.

Lockheed Shares Satellite Connectivity Options

Hackaday - 8 hours 19 minก่อน

In an unusual turn of events, Lockheed Martin has released technical “payload accommodation information” for three of their satellite busses. In layperson’s terms, if you wanted to build a satellite and weren’t sure what guidelines to follow these documents may help you learn if Lockheed Martin has a platform to help you build it.

An opportunity to check out once-confidential information about satellites sounds like a perfect excuse to dig through some juicy documentation, though unfortunately this may not be the bonanza of technical tidbits the Hackaday reader is looking for. Past the slick diagrams of typical satellites in rocket fairings, the three documents in question primarily provide broad guidance. There are notes about maximum power ratings, mass and volume guidelines, available orbits, and the like. Communication bus options are varied; there aren’t 1000BASE-T Ethernet drops but multiply redundant MIL-STD-1553B might come standard, plus telemetry options for analog, serial, and other data sources up to 100 Mbps. Somewhat more usual (compared to your average PIC32 datasheet) are specifications for radiation shielding and it’s effectiveness.

In the press release EVP [Rick Ambrose] says “we’re sharing details about the kinds of payloads we can fly…” and that’s exactly what these documents give us. Physical ballpark and general guidelines about what general types of thing Lockheed has capability to build launch. Hopefully the spirit of openness will lead to the hoped-for increase in space utilization.

If you take Lockheed up on their offer of satellite development, don’t forget to drop us a tip!

[Via the Washington Post]

Google Builds A Synthesizer With Neural Nets And Raspberry Pis.

Hackaday - 11 hours 19 minก่อน

AI is the new hotness! It’s 1965 or 1985 all over again! We’re in the AI Rennisance Mk. 2, and Google, in an attempt to showcase how AI can allow creators to be more… creative has released a synthesizer built around neural networks.

The NSynth Super is an experimental physical interface from Magenta, a research group within the Big G that explores how machine learning tools can create art and music in new ways. The NSynth Super does this by mashing together a Kaoss Pad, samples that sound like General MIDI patches, and a neural network.

Here’s how the NSynth works: The NSynth hardware accepts MIDI signals from a keyboard, DAW, or whatever. These MIDI commands are fed into an openFrameworks app that uses pre-compiled (with Machine Learning!) samples from various instruments. This openFrameworks app combines and mixes these samples in relation to whatever the user inputs via the NSynth controller. If you’ve ever wanted to hear what the combination of a snare drum and a bassoon sounds like, this does it. Basically, you’re looking at a Kaoss pad controlling rompler that takes four samples and combines them, with the power of Neural Networks. The project comes with a set of pre-compiled and neural networked samples, but you can use this interface to mix your own samples, provided you have a beefy computer with an expensive GPU.

Not to undermine the work that went into this project, but thousands of synth heads will be disappointed by this project. The creation of new audio samples requires training with a GPU; the hardest and most computationally expensive part of neural networks is the training, not the performance. Without a nice graphics card, you’re limited to whatever samples Google has provided here.

Since this is Open Source, all the files are available, and it’s a project that uses a Raspberry Pi with a laser-cut enclosure, there is a huge demand for this machine learning Kaoss pad. The good news is that there’s a group buy on Hackaday.io, and there’s already a seller on Tindie should you want a bare PCB. You can, of course, roll your own, and the Digikey cart for all the SMD parts comes to about $40 USD. This doesn’t include the OLED ($2 from China), the Raspberry Pi, or the laser cut enclosure, but it’s a start. Of course, for those of you who haven’t passed the 0805 SMD solder test, it looks like a few people will be selling assembled versions (less Pi) for $50-$60.

Is it cool? Yes, but a basement-bound producer that wants to add this to a track will quickly learn that training machine learning algorithms cost far more than playing with machine algorithms. The hardware is neat, but brace yourself for disappointment. Just like AI suffered in the late 60s and the late 80s. We’re in the AI Renaissance Mk. 2, after all.

3D Printed Antenna is Broadband

Hackaday - 14 hours 18 minก่อน

Antennas are a tricky thing, most of them have a fairly narrow range of frequencies where they work well. But there are a few designs that can be very broadband, such as the discone antenna. If you haven’t seen one before, the antenna looks like — well — a disk and a cone. There are lots of ways to make one, but [mkarliner] used a 3D printer and some aluminum tape to create one and was nice enough to share the plans with the Internet.

As built, the antenna works from 400 MHz and up, so it can cover some ham bands and ADS-B frequencies. The plastic parts act as an anchor and allow for coax routing. In addition, the printed parts can hold a one-inch mast for mounting.

Generally, a discone will have a frequency range ratio of at least 10:1. That means if the lower limit is 400 MHz, you can expect the antenna to work well up to around 4 GHz. The antenna dates back to 1945 when [Armig G. Kandoian] received a patent on the design. If you want to learn more about the theory behind this antenna, you might enjoy the video, below.

You often see high-frequency discones made of solid metal, or — in this case — tape. However, at lower frequencies where the antenna becomes large, it is more common to see the surfaces approximated by wires which reduces cost, weight, and wind loading.

As an example, we looked at an antenna made from garden wire. Perhaps the opposite of a discone is a loop antenna which works only on a very narrow range of frequencies.

Cracking an Encrypted External Hard Drive

Hackaday - 17 hours 19 minก่อน

As far as hobbies go, auditing high security external hard drives is not terribly popular. But it’s what [Raphaël Rigo] is into, and truth be told, we’re glad it’s how he gets his kicks. Not only does it make for fascinating content for us to salivate over, but it’s nice to know there’s somebody with his particular skill set out there keeping an eye out for dodgy hardware.

No word on how the “Secret Wang” performs

The latest device to catch his watchful eye is the Aigo “Patriot” SK8671. In a series of posts on his blog, [Raphaël] tears down the drive and proceeds to launch several attacks against it until he finally stumbles upon the trick to dump the user’s encryption PIN. It’s not exactly easy, it did take him about a week of work to sort it all out, but it’s bad enough that you should probably take this particular item off the wishlist on your favorite overseas importer.

[Raphaël] treats us to a proper teardown, including gratuitous images of chips under the microscope. He’s able to identify a number of components on the board, including a PM25LD010 SPI flash chip, Jmicron JMS539 USB-SATA controller, and Cypress CY8C21434 microcontroller. By hooking his logic analyzer up to the SPI chip he was able to dump its contents, but didn’t find anything that seemed particularly useful.

The second post in the series has all the gory details on how he eventually gained access to the CY8C21434 microcontroller, including a description of the methods which didn’t work (something we always love to see). [Raphaël] goes into great detail about the attack that eventually busted the device open: “cold boot stepping”. This method allowed him to painstakingly copy the contents of the chip’s flash; pulling 8192 bytes from the microcontroller took approximately 48 hours. By comparing flash dumps he was able to eventually discover where the PIN was being stored, and as an added bonus, found it was in plaintext. A bit of Python later, and he had a tool to pull the PIN from the drive’s chip.

This isn’t the first time we’ve seen a “secure” hard drive that ended up being anything but. We’ve even been witness to a safe being opened over Bluetooth. Seems like this whole “Security by Obscurity” thing might not be such a hot idea after all…

Free PCB coupon via Facebook to 2 random commenters

dangerous prototype - 19 hours 58 minก่อน

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • We’ll contact you via Facebook with a coupon code for the PCB drawer.
  • Limit one PCB per address per month, please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

Go Big Or Go Home – This Arduino RC Car Can Take You There

Hackaday - 20 hours 18 minก่อน

Whether we like it or not, eventually the day will come where we have to admit that we outgrew our childhood toys — unless, of course, we tech them up in the name of science. And in some cases we might get away with simply scaling things up to be more fitting for an adult size. [kenmacken] demonstrates how to do both, by building himself a full-size 1:1 RC car. No, we didn’t forget a digit here, he remodeled an actual Honda Civic into a radio controlled car, and documented every step along the way, hoping to inspire and guide others to follow in his footsteps.

To control the Civic with a standard RC transmitter, [kenmacken] equipped it with a high torque servo, some linear actuators, and an electronic power steering module to handle all the mechanical aspects for acceleration, breaking, gear selection, and steering. At the center of it all is a regular, off-the-shelf Arduino Uno. His write-up features plenty of videos demonstrating each single component, and of course, him controlling the car — which you will also find after the break.

[kenmacken]’s ultimate goal is to eventually remove the radio control to build a fully autonomous self-driving car, and you can see some initial experimenting with GPS waypoint driving at the end of his tutorial. We have seen the same concept in a regular RC car before, and we have also seen it taken further using neural networks. Considering his background in computer vision, it will be interesting to find out which path [kenmacken] will go here in the future.

Are you Dying to Upload Your Brain?

Hackaday - 21 hours 49 minก่อน

Cryonics — freezing humans for later revival — has been a staple of science fiction for ages. Maybe you want to be cured of something presently incurable or you just want to see the future. Of course, ignoring the problem of why anyone wants to thaw out a 500-year-old person, no one has a proven technology for thawing out one of these corpsicles. You are essentially betting that science will figure that out sometime before your freezer breaks down. A new startup called Nectome funded by Y Combinator wants to change your thinking about preservation. Instead of freezing they will pump you full of preservatives that preserve your brain including fine structures that scientists currently believe contain your memories.

Nectome’s strategy isn’t to have you revived like in conventional cryonics. They think the technology to do high definition scans of your preserved brain will exist soon. Those scans might allow future scientists to recreate your brain in a simulation. That isn’t really the same as coming back to life, though. At least we don’t imagine it is.

The company bills their process as archiving your brain, although since the process kills you, you are going to need to be legally eligible for euthanasia to take advantage of the process. There is a belief that structures known as connectomes hold your memories and these are preserved using this process. You can watch a TED talk about that subject, below.

Like all of these preservation strategies, there are a lot of unknowns. We aren’t sure that everything necessary persists because we don’t totally understand how the brain works. We also don’t know if anyone will ever figure out how to use these brains to simulate you back into existence. Then there’s the perennial problem of waking up to find yourself enslaved by an evil overlord or that your body is a warship in the service of a totalitarian regime.

For example, there is mounting evidence that your brain could really be a quantum computer. That would explain a lot, but even if it is wrong, there’s no way to know there isn’t something else totally not understood going on in there.

So how about it? Would you let them kill you to preserve your brain? Will anyone bother to boot up a copy of you in the future? If so, why? After all, according to all the smart people, you’ll just wake up to serve our robot overlords. If you just want to stimulate your brain, try DARPA.



Microsoft adds HEIF image support to Windows 10

Liliputing - 21 hours 55 minก่อน

Google Android P isn’t the only operating system gaining native support for the new High Efficiency Image File Format (HEIF). Microsoft is rolling out new preview builds of Windows 10 with native support for the new file format which brings better compression so that you can get higher-quality pictures at lower file sizes. But that’s […]

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Deals of the Day (3-16-2018)

Liliputing - 23 hours 16 minก่อน

Amazon is continuing to offer the 4K HDR-ready Fire TV media streamer for $45 (or $25 off its list price) to Prime members today, and the 1080p-ready Fire TV Stick is on sale for $25 (or $15 off). But those aren’t the only deals on media streamers today. Best Buy is running a 2-day sale […]

The post Deals of the Day (3-16-2018) appeared first on Liliputing.

Mechanisms: Gears

Hackaday - 23 hours 18 minก่อน

Even before the Industrial Revolution, gears of one kind or another have been put to work both for and against us. From ancient water wheels and windmills that ground grain and pounded flax, to the drive trains that power machines of war from siege engines to main battle tanks, gears have been essential parts of almost every mechanical device ever built. The next installment of our series on Mechanisms will take a brief look at gears and their applications.

Spurring Progress Along

As is often the case, evolution is the best inventor, and a geared mechanism linking the rear legs of juvenile planthopper insects predates the human invention of gears by a couple of billion years. Human use of gears dates back at least to third-century BC China, and the technology spread rapidly and widely. Within a few hundred years, precisely machined metal gears had enabled complex geared devices like the Antikythera mechanism to be built in Greece.

At its simplest, a gear is nothing more than a wheel with some sort of teeth cut into its circumference. The teeth are sized and shaped to mesh with teeth on other mechanical elements to transmit torque. Multiple gears connected in series are called a gear train, and if the diameters of gears in the gear train are different, the torque transmitted will be proportional to the difference. So, if the driving gear has a diameter of 1 cm and the driven gear is 10 cm across, the gear train will increase the torque 10-fold while reducing the rotational speed by a factor of 10.

Helical involute gears, generated by [Greg Frost]’s classic OpenSCAD code.The simplest gears, with teeth cut straight across the face of the circumference of a disk, are called spur gears. Many low to medium speed gear trains use spur gears, which have a simple geometry that’s easy to mass produce. But spur gears have some disadvantages. The axes of spur gears all have to be parallel to each other within the gear train, so there’s no way to transmit power to another rotational plane. Also, because the entire width of the tooth surface meshes at once, spur gears tend to make a lot of noise at higher speeds as the teeth clack together.

To counter this, teeth can be cut at an angle to the axis of rotation. Skewing the teeth like this around the circumference of the gear results in a helical pattern, hence the name helical gear. Not only are helical gears quieter, they can also be crossed to transmit power at a right angle. The tradeoff is that because of the skewed teeth, helical gears impart thrust along their axes. The thrust can be dealt with using thrust bearings, like tapered roller bearings, or by using two helical gears with opposing teeth directions on the same shaft to cancel out the axial thrust. This results in the beautiful herringbone gear seen in many high-power applications like wind turbines.

Powdered Gears

For the longest time, producing metal gears was a complex process involving multiple machining steps to produce teeth with the desired geometry. Teeth can be cut by any number of machining operations, like broaching, milling, shaping, or grinding.

But gear cutting is time-consuming and expensive, so most gears these days are produced by some kind of molding operation. Plastic gears of the kind we hate to see when we look inside a power tool built to a price point are easily produced by injection molding, and despite their bad reputation, they can result in perfectly serviceable if not particularly long-lived gear trains. But metal gears can also be molded, with powdered metal gears now making a huge share of the market.

Powdered metal gears are produced by filling a mold with very fine metal alloy powder mixed with binders and lubricants. The powder in the mold is compressed by a hydraulic ram with a tool matching the shape of the mold, and the tremendous pressure fuses the metal particles together into a solid strong enough to be handled. The green parts are then heated to permanently fuse the particles into the final metal part which in many cases is ready to use with no further machining.

Roll Your Own

While powder metallurgy is out of reach for most home shops, DIY gears are very much doable by anyone with access to some basic machine tools. We’ll never get enough of watching [Chris] machine the gears and pinions of the Clickspring clock, and while those gears are highly specialized for the world of metrology, many of the same principles apply to gears for other applications. 3D-printing is making custom gear trains possible too, and the results can be surprisingly robust under the right conditions. And don’t forget CNC routers, which are turning out gears large and small in all sorts of materials.

It’s hard to even scratch the surface of what goes into the engineering behind gears — tooth geometry, pressure angles, lines of contact — nor can we cover the really interesting gears, like harmonic drives and epicyclic gears. But this is a start at least, and a taste of what you’re in for when you start adding gears to your builds. Open the floodgates of awesome gear projects in the comments!

We’re Hiring: Come Join Us!

Hackaday - ศุกร์, 03/16/2018 - 23:00

The Hackaday writing crew goes to great lengths to cover all that is interesting to engineers and engineering enthusiasts. We find ourselves stretched a bit thin and it’s time to ask for help. Want to lend a hand while making some extra dough to plow back into your projects? These are work-from-home (or wherever you like) positions and we’re looking for awesome, motivated people to help guide Hackaday forward!

Contributors are hired as private contractors and paid for each article. You should have the technical expertise to understand the projects you write about, and a passion for the wide range of topics we feature. If you’re interested, please email our jobs line, and include:

  • Details about your background (education, employment, etc.) that make you a valuable addition to the team
  • Links to your blog/project posts/etc. which have been published on the Internet
  • One example post written in the voice of Hackaday. Include a banner image, at least 150 words, the link to the project, and any in-links to related and relevant Hackaday features

What are you waiting for? Ladies and Gentlemen, start your applications!

Massive Shift Register Switches Lights

Hackaday - ศุกร์, 03/16/2018 - 22:30

Sometimes you have to switch a light. Maybe it’s an LED but sometimes it’s mains-powered. That’s not too hard, a transistor and a relay should do it. If you have to switch more lights, that’s not too bad either, as long as your microcontroller has enough free GPIOs. But, if you need to switch a large number of lights, like 256 of them, for example, you’re going to need something else.

[Jan]’s project didn’t switch quite that many lights, but 157 of them is still enough of a chore to need a creative solution so he decided to use a 256-bit shift register to do the legwork. The whole thing is powered by a NodeMCU ESP8266 and was professionally built on DIN rails in a metal enclosure.

The build is interesting, both from a technical point of view and from an artistic one. It looks like it uses more than a mile of wiring, too. The source code is also available on the project page if you happen to have a need for switching a huge number of lightbulbs. Incandescent blulbs aren’t only good for art installations and lamps, though, they can also be used in interesting oscillator circuits too.

Google Lens comes to iOS (via Google Photos app)

Liliputing - ศุกร์, 03/16/2018 - 22:01

Google Lens began rolling out to (some) Android devices last year before expanding to additional devices earlier this year. Now Google Lens isn’t just for Android anymore. Google has announced that it’s rolling out a Google Lens preview for iOS starting this week. It’s part of the Google Photos app for iPhone and iPad. Google Lens […]

The post Google Lens comes to iOS (via Google Photos app) appeared first on Liliputing.

Linux Fu: File Aliases, Links, and Mappings

Hackaday - ศุกร์, 03/16/2018 - 21:01

Have you heard it said that everything in Linux is a file? That is largely true, and that’s why the ability to manipulate files is crucial to mastering Linux Fu.

One thing that makes a Linux filesystem so versatile is the ability for a file to be many places at once. It boils down to keeping the file in one place but using it in another. This is handy to keep disk access snappy, to modify a running system, or merely to keep things organized in a way that suits your needs.

There are several key features that lend to this versatility: links, bind mounts, and user space file systems immediately come to mind. Let’s take a look at how these work and how you’ll often see them used.


There are two kinds of links: hard and soft (or symbolic). Hard links only work on a single file system (that is, a single disk drive) and essentially makes an alias for an existing file:

ln /home/hackaday/foo /tmp/bar

If you issue this command, the file in /home/hackaday/foo (the original file) and the file /tmp/bar will be identical. Not copies. If you change one, the other will change too. That makes sense because there is only one copy of the data. You simply have two identical directory entries. Note the order of the arguments is just like a copy command. the File foo is the original file and the new link you’re creating is called bar.

These are not super useful because they do require the files to be on the same file system. They can also be hard to maintain since it is not always obvious what’s going on internally. Using the -l option (that’s a lower case ‘L’) on an ls command shows the number of links to a particular file. Usually, this is one, although directories will have more because each .. reference from a subdirectory will count as a link as well as the actual entry (.) and the entry in the parent directory. If you want to find all the hard links that are the same, you’ll need to search the file system (use find and check out the -samefile option).

Symbolic links are much more useful since they can span file systems. Essentially, a symbolic link or symlink is just a file that contains the name of another file. The file system knows that when you work with that file, you really mean the referenced file. The command to create is the same, with a single option added:

ln -s /home/hackaday/foo /tmp/bar

A complete directory list shows symbolic links very clearly. There are a few things you have to watch for. First, you can create circular links even though the tools try to detect that and prevent it. In other words, fileA might refer to fileB which refers to fileC that refers back to fileA. Linux will eventually stop after a certain number of indirections to prevent this from taking out the computer.

Another issue is that the target file might not exist. This could happen, for example, when you delete the original file. Finding all the symlinks requires a search of the file system, just like hard links, so it is not easy to find these broken links.

What is it good for? Imagine you have a working directory for a PCB router. There is a temporary directory in that working directory called scratch. You notice that disk I/O to the scratch directory is eating up most of the execution time of the program. You could use a symlink to easily point the scratch directory to a RAM disk or a solid state disk drive to improve performance.

Image Source: Disk Pack by Steve Parker CC-BY 2.0 Bind Mounts

Many Linux file systems support the idea of bind mounting. This lets you mount a directory somewhere else on the file system. This is similar to doing a symlink to a directory, but the specifics are a little different. For one thing, the mount is transient whereas a symlink is as permanent as the file system it resides in. For another, a mount point can replace an existing directory without destroying it (including becoming a new root directory with the chroot command).

In fact, chroot is probably the most frequent use of bind mounts. You want to prepare a new root directory for a system — possibly a remote system — and you are still booted on the old root. An easy way to fake things is to bind mount “special” file systems like /dev and /proc into the new root and then chroot to run things like grub.

For Linux, you normally create a bind mount using the mount command:

mount -o bind /dev /home/hackaday/bootimage/dev

This command replicates /dev into the bootimage directory.

BSD offers a nullfs that can accomplish the same thing. There’s also a user file system called bindfs that does a similar task.

In addition to building fake root file systems, you can also use a bind mount to reveal directories that are hidden behind a regular mount. For example, suppose you wanted to create a RAM drive for your /tmp directory:

mount -t tmpfs -o size=512M tmpfs /tmp

Anything that had been in /tmp is now hidden. However, consider this command:

mount -o bind /tmp /oldtmp

Now /oldtmp will have the contents of /tmp before the RAM drive mount.

If you want a refresher on mounting in general, check out the video below. It talks about regular mounts and loop mounts (used to mount a file — like an ISO file — instead of a device).

User Space File Systems

Historically, adding a file system meant writing kernel code (usually a kernel module). However, using Filesystem in User Space — known as FUSE — anyone can write code that looks like a file system. In fact, if you want to build a sandbox without directly using bind mounts, check out sandboxfs.

There are lots of user file systems to handle a variety of tasks. Some do special things with files like mounting an archive as a directory. Others expose other kinds of data as files (for example, blog posts on a remote web site). There are file systems that can tag real files, convert file types on the fly, or even delete old files when space runs out. I find sshfs particularly useful since it can mount a remote directory with no special software on the remote side.

Writing your own FUSE module is fairly simple. There are several good tutorials out there. If you use C++, you can get away with a pretty simple implementation. If you are interested in seeing how it would work using Python, check out the video below.

Wrap Up

In traditional Unix-based systems, everything was a file. For better or worse, that philosophy isn’t as pervasive as it used to be. Still, files and file-like things continue to be a big part of Linux and knowing how to manipulate links, mount directories, and use FUSE file systems can be a big help in administering and setting up any Linux-based system from a PC to a Raspberry Pi.

LG G7 may have a notch… that you can “disable” with a software trick

Liliputing - ศุกร์, 03/16/2018 - 20:05

So here’s the thing about smartphones with display notches: they offer more screen real estate by allowing device makers to offer a slim top bezel with a cut-out in the display for a camera and other sensors. But they also look funny, since the display wraps around the cut-out, which can pose a problem when […]

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Gamecube Dock For Switch Mods Nintendo with More Nintendo

Hackaday - ศุกร์, 03/16/2018 - 18:00

[Dorison Hugo] let us know about a project he just completed that not only mods Nintendo with more Nintendo, but highlights some of the challenges that come from having to work with and around existing hardware. The project is a Gamecube Dock for the Nintendo Switch, complete with working Gamecube controller ports. It looks like a Gamecube with a big slice out of it, into which the Nintendo Switch docks seamlessly. Not only that, but thanks to an embedded adapter, original Gamecube controllers can plug into the ports and work with the Switch. The original orange LED on the top of the Gamecube even lights up when the Switch is docked. It was made mostly with parts left over from other mods.

The interesting parts of this project are not just the attention to detail in the whole build, but the process [Dorison] used to get everything just right. Integrating existing hardware means accepting design constraints that are out of one’s control, such as the size and shape of circuit boards, length of wires, and often inconvenient locations of plugs and connectors. On top of it all, [Dorison] wanted this mod to be non-destructive and reversible with regards to the Nintendo Switch dock itself.

To accomplish that, the dock was modeled in CAD and 3D printed. The rest of the mods were all done using the 3D printed dock as a stand-in for the real unit. Since the finished unit won’t be painted or post-processed in any way, any scratches on both the expensive dock and the Gamecube case must be avoided. There’s a lot of under-cutting and patient sanding to get the cuts right as a result. The video (embedded below) steps through every part of the process. The final screws holding everything together had to go in at an odd angle, but in the end everything fit.

We’ve seen [Dorison]’s work before with the custom 3D printed Raspberry Pi Zero case which was made to look like a mini PS One console; he compared results of SLA versus FDM printing in the process.

Google Light Fields Trying to Get the Jump on Magic Leap

Hackaday - ศุกร์, 03/16/2018 - 15:00

Light Field technology is a fascinating area of Virtual Reality research that emulates the way that light behaves to make a virtual scene look more realistic. By emulating light coming from multiple angles entering the eye, the scenes look more realistic because they look closer to reality. It is rumored to be part of the technology included in the forthcoming Magic Leap headset, but it looks like Google is trying to steal some of their thunder. The VR research arm of the search giant has released a VR app called Welcome to Light Fields that uses a similar technique on existing VR headsets, such as those from Oculus and Microsoft.

The magic sauce is in the way the image is captured, as Google uses a semicircular arrangement of 13 GoPro cameras that are rotated to capture about a thousand images. The captured images are then stitched together by Google’s software to create the final image, which has a light field effect. It is thought that the forthcoming Magic Leap headset needs special optics to create this effect but the Google version works on standard VR headsets. According to those who tried it, the effect works well, but has some quirks: it only works on still images at the moment, and any movement while the camera is rotating ruins the effect. A writer from Technology Review who got to try the Google software also notes that people in the shot don’t work: because they naturally follow the camera with their eyes, they seem to be following your view as you pan around the VR image, like one of those creepy portraits.

A Plywood Laptop For Your Raspberry Pi

Hackaday - ศุกร์, 03/16/2018 - 12:00

[Rory Johnson] writes in to tell us about PlyTop Shell, a Creative Commons licensed design for a laser cut wooden laptop that he’s been working on since 2016. It’s designed to accommodate the Raspberry Pi (or other similarly sized SBCs), and aims to provide the builder with a completely customizable mobile computer. He’s got a limited run of the PlyTop up for sale currently, but if you’ve got the necessary equipment, you can start building yours while you wait for that new Pi 3B+ to arrive.

Originally [Rory] was working on a 3D printed design, but quickly ran into problems. The vast majority of 3D printers don’t have nearly the build volume to print out a laptop case in one shot, so the design needed to be broken up into multiple smaller pieces and then grafted together into the final case. Not only did this take a long time and a lot of material, but the final result had the rather unfortunate appearance of a plastic quilt.

Eventually he got hooked up with a maker collective in Minneapolis that had a laser cutter, and the PlyTop was born. There’s still a 3D printed component in the design that goes in the screen hinge, but the rest of the PlyTop is cut out of a three 2′ x 4′ sheets of 1/8″ Baltic birch plywood. As you might expect, plenty of fasteners are required, but [Rory] has a complete Bill of Materials (complete with purchase links) for everything you’ll need to turn the cut pieces into a fully fledged laptop. He’s considering selling kits in the future, but is still working on the logistics.

In keeping with the idea of complete flexibility, there’s no defined layout for the internals of the PlyTop. Rather, there’s an array of star-shaped openings on the bottom plate that allow the builder to connect hardware components up in whatever way works for them. [Rory] actually suggests just holding everything down with zip ties to allow for ease of tinkering.

He’s also come up with a list of suggested hardware for the keyboard, touchpad, and display; but those are really just suggestions. The design is open enough that it shouldn’t take much work to adapt to whatever gear you’ve got laying around.

Of course, this isn’t the first open source laptop we’ve seen here at Hackaday. It isn’t even the first wooden one. But we love the lines of the PlyTop and the focus on complete customization.

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