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Updated: 24 min 13 sec ago

Google Builds A Synthesizer With Neural Nets And Raspberry Pis.

1 hour 23 min ago

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

Fri, 03/16/2018 - 22:00

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

Fri, 03/16/2018 - 19:00

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…

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

Fri, 03/16/2018 - 16:00

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?

Fri, 03/16/2018 - 14:30

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.



Mechanisms: Gears

Fri, 03/16/2018 - 13:01

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!

Fri, 03/16/2018 - 12:00

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

Fri, 03/16/2018 - 11:30

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.

Linux Fu: File Aliases, Links, and Mappings

Fri, 03/16/2018 - 10:01

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.

Gamecube Dock For Switch Mods Nintendo with More Nintendo

Fri, 03/16/2018 - 07:00

[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

Fri, 03/16/2018 - 04:00

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

Fri, 03/16/2018 - 01:00

[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.

A Pin Pusher To Make Life Easier

Thu, 03/15/2018 - 22:00

Picture the scene: you’ve whipped up an amazing new gadget, your crowdfunding campaign has gone well, and you’ve got a couple hundred orders to fill. Having not quite hit the big time, you’re preparing to tackle the production largely yourself. Parts begin to flood in, and you’ve got tube after tube of ICs ready to populate your shiny new PCBs? After the third time, you’re sick and tired of fighting with those irksome little pins. Enter [Stuart] with the answer.

It’s a simple tool, attractively presented. Two pieces of laser cut acrylic are assembled in a perpendicular fashion, creating a vertical surface which can be used to press pins out of IC tubes. [Stuart]’s example has rubber feet, though we could easily see this built into a work surface as well.

The build highlights two universal truths. One, that laser cutters are capable of producing elegant, visually attractive items almost effortlessly, something we can’t say about the garden variety 3D printer. Secondly, all it takes is a few little jigs and tools to make any production process much easier. This is something that’s easy to see in the many factories all over the world – special single-purpose devices that make a weird, tricky task almost effortless.

In DIY production lines, testing is important too – so why not check out this home-spun test jig?

A Compensated Thermocouple Amp, Ready for Arduino

Thu, 03/15/2018 - 19:00

When you want to measure temperature with an Arduino or other microcontrollers, there are a ton of options for sensors. Temperature chips and sensor modules abound, some with humidity sensors built-in and all with easy interfacing and an expansive supporting code library. But dip one of those sensors into, say, molten aluminum, and you’ve got a problem.

If you’re measuring something hot, you need a thermocouple. Trouble is, the signal from a thermocouple is pretty small, and needs amplification and compensation before being fed into the ADC of a typical microcontroller. Unable to find a commercial amp to meet his needs, [MonkHelios] built his own thermocouple amp for microcontrollers. The design is centered around an LTC2053 instrumentation amp, which does the job of converting the K-type thermocouple’s 40.6μV/°C output to a nicely scaled 10mV/°C range, just right for ADC consumption. He also thoughtfully included an LT1025 cold-junction compensator; thermocouple amps are referenced to 0°C, so the compensator measures the actual temperature of the cold end of the junction and scales the output accordingly. The whole amp is nicely laid out on a DIY single-sided PCB with meticulously applied solder mask — this is one of the nicest home-etched boards we’ve seen in a long time.

[Bil Herd] designed a similar thermocouple amp not too long ago himself, so you might check that out too.  Or maybe you need the basics of instrumentation amps? Our “Beyond Measure” series will get you started.

Carbon Augmented Spider Silk

Thu, 03/15/2018 - 16:00

Some of the creepy-crawlers under our feet, flitting through the air, and waiting on silk webs, incorporate metals into their rigid body parts and make themselves harder. Like Mega Man, they absorb the metals to improve themselves. In addition to making their bodies harder, silk-producing creatures like worms and spiders can spin webs with augmented properties. These silks can be conductive, insulating, or stronger depending on the doping elements.

At Italy’s University of Trento, they are pushing the limits and dosing spiders with single-wall carbon nanotubes and graphene. The carbon is suspended in water and sprayed into the spider’s habitat. After the treatment, the silk is measured, and in some cases, the silk is significantly tougher and surpasses all the naturally occurring fibers.

Commercial spider silk harvesting hasn’t been successful, so maybe the next billionaire is reading this right now. Let’s not make aircraft-grade aluminum mosquitoes though. In fact, here’s a simple hack to ground mosquitoes permanently. If you prefer your insects alive, maybe you also like their sound.

Thank you for the tip, [gippgig].

Get Together and Hack this Saturday at World Create Day!

Thu, 03/15/2018 - 14:31

Spend some time with the Hackaday Community in your area this weekend. There are more than 100 community organized meetups happening this Saturday for Hackaday World Create Day. Check the big map for one near you and click the “Join this event” button in the upper right of their events page to let them know you’re coming.

Sticker packs we’ve been sending out to local event organizers.

It’s always a blast to get together with friends new and old to work on a project you’ve been itching to build. Grab something from your work bench and have fun geeking out about it in the company of others. This is a great opportunity to get started on your 2018 Hackaday Prize entry. Brainstorm ideas for a project, get advice on your early build plans, and consider forming a team. Submit what you come up with this Saturday as your entry and improve upon it over the coming weeks.

Can you still sign up to host World Create Day? Of course! Fill out this form and we’ll get you set up right away.

If you simply can’t make it to a live event, you can still take part. Set aside time to hack and show off the stuff you’re working on through social media. We have a Tweetwall set up (great to put up on the projector during group meetups) which shares Tweets with the hashtag #WorldCreateDay.

Don’t Forget to Tell the Story of Your World Create Day

We’re on the lookout for cool stories and interesting hacks from your meetup so that we can feature them here on Hackaday. Last year we featured a number of meetups, like automated gardening in Cyprus and etching Robot PCBs in Osaka. There was also a roundup with baby guitar amps, power racing series, and Wacky Waving costume assembly. It’s truly a worldwide thing, here’s a roundup that spanned India, Austrailia, and the USA.

Take pictures, write about what goes one, and tag everything #WorldCreateDay so we have the info to report on your meetup!

The HackadayPrize2018 is Sponsored by:

Building a Portable Solar-Powered Spot Welder: Nearly Practical!

Thu, 03/15/2018 - 13:01

Last time, we covered storing and charging a 3000 Farad supercapacitor to build a solar-powered, portable spot welder. Since then, I’ve made some improvements to the charging circuit and gotten it running. To recap, the charger uses a DC-DC buck converter to convert a range of DC voltages down to 2.6 V. It can supply a maximum of 5 A though, and the supercapacitor will draw more than that if allowed to.

Capacitor charge current decreases with time as the capacitor charges. Source: Hyperphysics

After some failed attempts, I had solved that by passing the buck converter output through a salvaged power MOSFET. A spare NodeMCU module provided pulse width modulated output that switched the MOSFET on for controlled periods of time to limit the charging current. That was fine, but a constant-voltage charger really isn’t the right way to load up a capacitor. Because the capacitor plates build up a voltage as it charges, the current output from a constant-voltage charger is high initially, but drops to a very low rate in the end.

To make something more like a constant-current charger, and lacking a sense resistor, I connected the output to the ADC pin on the NodeMCU. It measures the voltage across the supercapacitor, and as it increases during charging, the NodeMCU increases the amount of time the MOSFET allows current to pass. In other words it increases the duty cycle as the capacitor charges. Note that the firmware I was using supported integer math only, which is why I didn’t just divide by 1.6 in the code:

pwm.setup(1, 1000, 900) pwm.start(1) function set_charge_rate() val = adc.read(0) duty = 800 - (val/2 + val/9) pwm.setduty(1, duty) end tmr.alarm(1, 3000, 1, function() set_charge_rate() end)

This worked much better, but the charge rate was still slower than it could be above around 2.1 volts. To speed it up a bit, I just increased the duty cycle to a fixed value above that point:

pwm.setup(1, 1000, 900) pwm.start(1) function set_charge_rate() val = adc.read(0) if val < 635 then duty = 800 - (val/2 + val/9) print (val) print (duty) pwm.setduty(1, duty) elseif val > 634 then duty = 180 print (duty) pwm.setduty(1, duty) else end end tmr.alarm(1, 3000, 1, function() set_charge_rate() end)

After that last modification, the charge rate was much better and the components involved would get hot, but not alarmingly so. I set the output of the DC-DC converter to 2.6 V, and was able to charge the capacitor past 2.5 V without issue.

Now that the charger was satisfactory, it was time to add electrodes. I had some large copper ring terminals, which were the right size for some steel bolts I had lying around. Crimping wire into these required quite a bit of hammering, but the connection was extremely solid. For cabling, I used three-phase power cable with all three wires attached together to make one thick cable.

I bolted the ring terminals to the copper plates of the supercapacitor holder and to two short, thinner solid core wires that were the electrodes. While ugly, this gave the electrodes good mobility. It was pretty easy to apply them to metal plates and such. Finally, where there was exposed copper, I used heat shrink tubing as insulation.

So far, everything had gone pretty well, so I charged it up, grabbed a spare lithium cell and some tab wire, and gave it a try. When I applied the electrodes, a small spot on the tab wire got yellow-hot very fast without sparking. I quickly removed them… and the tab wire didn’t adhere at all. No matter how I tried, I couldn’t get it to weld in place, although it did heat up whatever material I touched the electrodes to rather well without any part of the device getting particularly hot itself. It feels like it just barely didn’t work, which was a bit frustrating. It did nicely obliterate the tab wire if left on too long though:

In hindsight, there are a few things I could have done better from the start. Most importantly, I should have used both capacitors to make a 5.4 V, 1500 F capacitor bank. Since I don’t know the internal resistance of the supercapacitor (I had incorrectly guessed around 30 mΩ), I should have erred on the side of pessimism. Looking at this working build that uses supercapacitors to weld copper, they had used four supercapacitors of similar size! So I charged both capacitors, sanded the electrodes clean, and hooked them up in series in a box for a quick test.

What a difference that made! When the electrodes touched the tab wire, they sparked lightly as expected rather than just heating the metal, and it welded into place. Certainly not the best weld, but with some practice I think it could be serviceable. (The actual welds are those spots on the left. The tab was damaged from previous attempts.)

So while this works with a charge of  5.2 V, I suspect it would be better with a third capacitor at 7.8 V. A question remains though: why do some builds seem to work well with only a single supercapacitor? I suspect that these unbranded capacitors didn’t pass quality control, and were sold gray market. A higher than expected internal resistance or lower capacity than claimed are not out of the question and would certainly affect the performance of a spot welder. Lesson learned: for spot welders use genuine parts. I’ve half a mind to open it up, expecting to see a smaller capacitor inside along with a whole bunch of sand. That being said, for $4 these would have been fantastic as part of a trickle charge system for a solar-powered sensor.

Failing that, these questionable parts would make excellent ballast or a terrible casserole. Your project suggestions are welcome!

Separators to be added later.

In any case, it was time to put it in a better box, make it portable, and attach a solar panel. That turned out to be refreshingly straightforward. I went and bought a larger weatherproof plastic box to enclose the supercapacitors. They’re arranged just as if they were large AA batteries.

I bought some slotted angled steel. This is pretty much my favorite construction material, it’s more or less scaled up Meccano. An interesting fact is that the existence of Meccano is what prevented a general patent for slotted angled steel, which allowed it to be emulated worldwide. I’ve seen buildings made from it.

I built a steel frame to fit a solar panel on top and contain all the parts. This is so it can be strapped to a motorbike or worn as a backpack using bungee cord — inspired by [Joe Kim]’s art for the first article. The solar panel is a 10 W, 18 V monocrystalline unit that I kept around to charge devices during long power outages that used to occur weekly (the power grid is much better now).

In sunlight, the charge time is limited more by the charge controller (in software) than the solar panel output. At the specified limit of 5 A, it just runs too hot. As a compromise, each capacitor has its own charge circuit, which can easily take 15 minutes to get from 1 V to a practical voltage.

Overall it works… but calling it amazingly practical would be quite a stretch. A more modest build using three or four smaller, branded supercapacitors would have likely worked better, charged faster, as well as being lighter, smaller, and cheaper… perhaps to the point of borderline commercial viability for people who need to weld battery tabs when the power is out. Or I could just give up portability and solar power altogether and use a microwave transformer to build the spot welder.

Reverse Engineer An X-Ray Image Sensor

Thu, 03/15/2018 - 11:30

If you think of a medical x-ray, it is likely that you are imagining a photographic plate as its imaging device. Clipped to your tooth by your dentist perhaps, or one of the infamous pictures of the hands of [Thomas Edison]’s assistant [Clarence Madison Dally].

As with the rest of photography, the science of x-ray imaging has benefited from digital technology, and it is now well established that your hospital x-ray is likely to be captured by an electronic imaging device. Indeed these have now been in use for so long that their first generation can even be bought by an experimenter for an affordable sum, and that is what the ever-resourceful [Niklas Fauth] with the assistance of [Jan Henrik], has done. Their Trophy DigiPan digital x-ray image sensor was theirs for around a hundred Euros, and though it’s outdated in medical terms it still has huge potential for the x-ray experimenter.

The write-up is a fascinating journey into the mechanics of an x-ray sensor, with the explanation of how earlier devices such as this one are in fact linear CCD sensors which track across the exposed area behind a scintillator layer in a similar fashion to the optical sensor in a flatbed scanner. The interface is revealed as an RS422 serial port, and the device is discovered to be a standalone unit that does not require any commands to start scanning. On power-up it sends a greyscale image, and a bit of Sigrok examination of the non-standard serial stream was able to reveal it as 12-bit data direct from the sensor. From those beginnings they progressed to an FPGA-based data processor and topped it all off with a very tidy power supply in a laser-cut box.

It’s appreciated that x-rays are a particularly hazardous medium to experiment with, and we note from their videos that they are using some form of shielding. The source is a handheld fluoroscope of the type used in sports medicine that produces a narrow beam. If you remember the discovery of an unexpected GameBoy you will be aware that medical electronics seems to be something of a speciality in those quarters, as do autonomous box carriers.

A Tale of Two Phases and Tech Inertia

Thu, 03/15/2018 - 10:01

What kind of power service is in the United States? You probably answered 120-volt service. If you thought a little harder, you might remember that you have some 240-volt outlets and that some industrial service is three phase. There used to be DC service, but that was a long time ago. That’s about it, right? Turns out, no. There are a very few parts of the United States that have two-phase power. In addition, DC didn’t die as quickly as you might think. Why? It all boils down to history and technological inertia.

Split Phase Power by Charles Esson CC-BY-SA 3.0

You probably have quite a few 120-volt power jacks in sight. It is pretty hard to find a residence or commercial building these days that doesn’t have these outlets. If you have a heavy duty electric appliance, you may have a 240-volt plug, too. For home service, the power company supplies 240 V from a center tapped transformer. Your 120V outlets go from one side to the center, while your 240V outlets go to both sides. This is split phase service.

Industrial customers, on the other hand, are likely to get three-phase service. With three-phase, there are three wires, each carrying the line voltage but out of phase with each other. This allows smaller conductors to carry more power and simplifies motor designs. So why are there still a few pockets of two-phase?

When Electricity Was New

It is easy to look back and realize that AC power transmission has advantages and why three-phase is used. But back when electricity was a new service, none of these things were obvious. Edison, Tesla, and Westinghouse famously battled between using AC and DC current. Back then, AC didn’t mean three-phase AC, though. Two-phase, where the phases were 90 degrees apart, was an easier system to analyze and generate. The famous generators at Niagara Falls, for example, produced two-phase. You can see ten 5,000 HP generators at the falls, below.

It was 1918 before mathematical tools for dealing with polyphase AC readily came about. By then, two-phase was pretty well entrenched. In many cases, once the superiority of three-phase was realized, things were just rewired. But high rise buildings were not always easy or practical to rewire.

Big City, Old Power

This was a similar situation with DC power. Did you know that Con Edison — New York City’s power company — still provided DC to some buildings until late 2007? Even then, the buildings didn’t switch everything to AC. They just installed converters so the DC motors that run infrastructure like the elevators didn’t need replacing. The conversion to AC started in 1928 and was supposed to take 45 years. Like most projects, it ran long and took nearly 80 years.

In the case of two-phase, though, there are still pockets of it in Philadelphia and Hartford Connecticut. This makes being an electrician in those cities a bit interesting and you can find services advertising their mastery of two-phase work. Incidentally, there are some breathtaking photographs of Philadelphia’s early twentieth century infrastructure. Take a look a the book Palazzos of Power: Central Stations of the Philadelphia Electric Company, 1900-1930.

You might wonder if the power companies in those two cities actually still maintain two-phase generators. As far as we can tell, no. They just convert from three-phase to two-phase using a Scott-T transformer (named after [Charles F. Scott] who worked for Westinghouse). You can see a typical configuration here.

March of Progress

We think of the march of technology as progressive, but it is amazing how many things hold on because of historical precedent. We still have AM radios, for example. My desktop computer can still boot MSDOS. There’s a lot of inertia even as new tech pushes out the old.

Why 120V? Because Edison’s first generators produced 110V (although, in fairness, 110V DC). After World War II, the nominal voltage kept creeping up until it settled on 120V by 1967. In 1899, a power company in Berlin decided to switch to 220V to increase its ability to distribute power. This took over Europe where 230V (raised up from 220) is the usual voltage.

Thanks to [Tom Frobase] who lived in Pennsylvania for suggesting this topic

Programming Linux Devices With Arduino And The Cloud

Thu, 03/15/2018 - 07:00

Back in the olden days, when the Wire library still sucked, the Arduino was just a microcontroller. Now, we have single board computers and cheap microcontrollers with WiFi built in. As always, there’s a need to make programming and embedded development more accessible and more widely supported among the hundreds of devices available today.

At the Embedded Linux Conference this week, [Massimo Banzi] announced the beginning of what will be Arduino’s answer to the cloud, online IDEs, and a vast ecosystem of connected devices. It’s Arduino Create, an online IDE that allows anyone to develop embedded projects and manage them remotely.

As demonstrated in [Massimo]’s keynote, the core idea of Arduino Create is to put a connected device on the Internet and allow over-the-air updates and development. As this is Arduino, the volumes of libraries available for hundreds of different platforms are leveraged to make this possible. Right now, a wide variety of boards are supported, including the Raspberry Pi, BeagleBone, and several Intel IoT boards.

The focus of this development is platform-agnostic and focuses nearly entirely on ease of use and interoperability. This is a marked change from the Arduino of five years ago; there was a time when the Arduino was an ATmega328p, and that’s about it. A few years later, you could put Arduino sketches on an ATtiny85. A lot has changed since then. We got the Raspberry Pi, we got Intel stepping into the waters of IoT devices, we got a million boards based on smartphone SoCs, and Intel got out of the IoT market.

While others companies and organizations have already made inroads into an online IDE for Raspberry Pis and other single board computers, namely the Adafruit webIDE and Codebender, this is a welcome change that already has the support of the Arduino organization.

You can check out [Massimo]’s keynote below.