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RTL-SDR Paves Way To Alexa Controlled Blinds

ศุกร์, 09/28/2018 - 03:00

You’d be forgiven for occasionally looking at a project, especially one that involves reverse engineering an unknown communication protocol, and thinking it might be out of your league. We’ve all been there. But as more and more of the devices that we use are becoming wireless black boxes, we’re all going to have to get a bit more comfortable with jumping into the deep end from time to time. Luckily, there are no shortage of success stories out there that we can look at for inspiration.

A case in point are the wireless blinds that [Stuart Hinson] decided would be a lot more useful if he could control them with his Amazon Alexa. There’s plenty of documentation on how to get Alexa to do your bidding, so he wasn’t worried about that. The tricky part was commanding the wireless blinds, as all he had to go on was the frequency printed on the back of the remote.

Luckily, in the era of cheap RTL-SDR devices, that’s often all you need. [Stuart] plugged in his receiver and fired up the incredibly handy Universal Radio Hacker. Since he knew the frequency, it was just a matter of tuning in and hitting the button on the remote a couple times to get a good capture. The software then broke it down to the binary sequence the remote was sending out.

Now here’s where [Stuart] lucked out. The manufacturers took the easy way out and didn’t include any sort of security features, or even bother with acknowledging that the signal had been received. All he needed to do was parrot out the binary sequence with a standard 433MHz transmitter hooked up to an ESP8266, and the blinds took the bait. This does mean that anyone close enough can take control of these particular blinds, but that’s a story for another time.

We took a look at the Universal Radio Hacker a year or so back, and it’s good to see it picking up steam. We’ve also covered the ins and outs of creating your own Alexa skills, if you want to get a jump on that side of the project.

The Redox Keyboard

ศุกร์, 09/28/2018 - 01:30

Alternative keyboard layouts like Colemak and Dvorak are nothing new; they allow easier access to more often used keys to reduce the strain placed on the hands during typing. Building on the popularity of the ergonomic Ergodox keyboard, [Mattia Dal Ben] has developed the Redox keyboard, the Reduced Ergodox, to make an even smaller, more ergonomic keyboard.

Like the Ergodox, the Redox uses a columnar layout, where the keys are laid out in columns, each column offset based on the corresponding finger. Where the Redox breaks away from the design of the Ergodox is the thumb keys. [Mattia] started having pain in his pinkies, so he wanted the thumb layouts to take away some of the extra work from the pinkies. The thumb cluster is smaller than its ancestor and includes an additional rotated thumb key.

The Redox has some great improvements over the Ergodox in order to help with the types of strain injuries most associated with typing, hopefully leading to a much nicer interaction with the peripheral that gets the most use.

The mechanical keyboard community is constantly coming up with great new designs and different DIY keyboards and we’ve featured many of them on the site. After you’ve checked out the pictures and schematics [Mattia] has created, take a look at this 3D printed mechanical keyboard, and details of a keyboard design and build were presented at the Hackaday Superconference in 2017.

The HackadayPrize2018 is Sponsored by:





Laser Noob: Getting Started With the K40 Laser

ศุกร์, 09/28/2018 - 00:01

Why spend thousands on a laser cutter/engraver when you can spend as little as $350 shipped to your door? Sure it’s not as nice as those fancy domestic machines, but the plucky K40 is the little laser that can. Just head on down to Al’s Laser Emporium and pick one up.  Yes, it sounds like a used car dealership ad, but how far is it from the truth? Read on to find out!

Laser cutting and engraving machines have been around for decades. Much like 3D printers, they were originally impossibly expensive for someone working at home. The closest you could get to a hobbyist laser was Epilog laser, which would still cost somewhere between $10,000 and $20,000 for a small laser system. A few companies made a go with the Epilog and did quite well – notably Adafruit used to offer laptop laser engraving services.

Over the last decade or so things have changed. China got involved, and suddenly there were cheap lasers on the market. Currently, there are several low-cost laser models available in various power levels. The most popular is the smallest – a 40-watt model, dubbed the K40. There are numerous manufacturers and there have been many versions over the years. They all look about the same though: A blue sheet metal box with the laser tube mounted along the back. The cutting compartment is on the left and the electronics are on the right. Earlier versions came with Moshidraw software and a parallel interface.

The K40 mechanics haven’t changed very much, but the electronics have been updated to USB with modern stepper drivers. Make no mistake, these are not “quality” machines. They are built down to a cost. Interlock switches are non-existent. Overheat protection for the tube is your problem. Low cooling water flow alarm? Nope, better keep an eye on that yourself. The cutting bed looks like a mixture of an afterthought and parts someone found in the spares bin. The exhaust duct is routed 3 inches into the cutting area. In other words, these are the perfect machines for a hacker.

I’ve been watching the K40 and similar machines on eBay for years. Originally these machines were shipped from China. It was a crapshoot if a large heavy gas filled glass tube would survive the trip halfway around the world. Now, many of the machines are shipping from California and other ports within the lower 48 states. I’m guessing the machines are shipped to a warehouse here in the USA, tested, then the good units are sent on to customers.

With all this in mind, I finally decided to jump in and get a K40 laser. My first problem was deciding which laser to buy. eBay and Alibaba are riddled with auctions from sellers with different versions of the K40. Everyone says they’re newer and better than the rest. Some boast different accessory packages, and things like air assist – but also cost more. There is enough information to throw even the most seasoned eBayer into analysis paralysis mode.

In the end, I decided to go with one of the cheaper (but not the cheapest) lasers with a digital front panel display. My model also came with a temperature readout for the cooling water, and wheels – for those who like to roll their benchtop lasers around.

I clicked the “buy it now” button and started waiting. The machine in its 62 lb crate would take about a week to ship from the west coast. That gave me plenty of time to order some safety equipment.

Laser Safety

While the K40 may be cheap, I didn’t want to skimp on safety equipment. There are many vendors for laser safe goggles online. There are plenty of them available from China, but I really didn’t want to risk my eyes to a company I had never heard of. I did some checking around and ended up ordering a pair manufactured by Honeywell. Amazon had them available on Prime, so they got to me before the K40 itself. Whichever pair you order, make sure they are rated for CO2 lasers. There are many types of lasers out there, and goggles meant to protect you from a UV medical laser won’t help much at all when it comes to an IR laser like the one in the K40. IR safe glasses will be clear, or nearly so. But don’t mistake them for bog standard safety glasses. These are specially made materials which will help keep you safe from the invisible blindness beam your K40 puts out when your other safety measures fail.

Lasers burn things, and it is unfortunately common for those things to catch fire inside the laser. I’m keeping a large ABC dry powder fire extinguisher near the printer. However, that’s only a stopgap. If you’ve ever had to use a powder extinguisher, you know how messy they are. To try to keep the K40 and the rest of my lab safe, I’m planning to invest in a gas extinguisher of some type. Either CO2 or Halotron, depending on which is safer for use in a basement room.

While I never plan to leave the laser running unattended, I also have smoke detectors in my lab. Finally, I added a carbon monoxide detector to make sure the K40 doesn’t fill the room with a silent killer.

Unboxing

Hackaday doesn’t do unboxing videos, but the impression I got while unpacking the K40 was that it is big – bigger than one would imagine from the photos. My machine measured 32″ wide x 19.75″ deep x 10.25″ high. Thankfully I had workbench space right near a window that made a perfect home.

Cooling

The K40 laser is water cooled. All the lasers include a coolant pump as one of the accessories. The pump I received is a wonder of cost reduction. It’s an aquarium or pond pump, with a magnetically coupled impeller. I was concerned when after use I saw water dripping out of the pump down the 120 V power cord. It turns out the back cover of the pump isn’t even sealed. It doesn’t need to be. The motor stator and coils are potted in black epoxy. As long as that potting compound is in place, nothing can get to the motor. It does seem to work well for keeping the cooling water flowing. However, I can’t say I completely trust it with the life of my laser tube. A mod may be in the future for this system.

For coolant, I’m using distilled water. My reservoir for these early tests is a simple shoebox-sized plastic container. It holds a gallon of water and keeps the pump submerged. If the laser isn’t going to be used for a few days, I dump the water and empty the tube by blowing into the inlet line.

Exhaust

Cutting things with a laser will produce smoke and fumes; that’s a given. The K40 comes with an exhaust fan which is rather anemic, to say the least. It’s literally a bathroom exhaust fan slapped on the back of the laser. Smoke is pulled through a slot cut in the back of the case and sent up the exhaust hose. I already have a large Dayton fan mounted in the window of my lab. While the unguarded blades are decidedly dangerous, it moves a crazy amount of air. This coupled with the stock exhaust fan was able to keep the smell of burning wood and plastic down to reasonable levels. However, I’ll definitely be upgrading the stock exhaust in the future.

Aligning The Optics

The first step in setting up one of these lasers is arguably the most dangerous: aligning the mirrors. This is why I bought good laser goggles. Working on the laser with the doors off is something you generally don’t want to do since you can’t control where the beam goes.

Keep the laser safety glasses on at all times, close the door, and make sure no one else walks into the room. My tube was so far out of alignment that the beam exited the case through the open door and made a small scorch mark on the wall behind my workbench. It would not have been good if someone else was standing there.

There are plenty of video tutorials out there for aligning the mirrors on a K40. I found this one to be particularly helpful. The idea is to make sure that the laser dot hits the center of each of the three mirrors in the beam path. Two of the mirrors move on an X-Y table, so it’s important to make sure the beam hits the same spot no matter where they are positioned. I used Post-it notes rather than the painter’s tape many of the tutorials call for. It’s much easier to see the burn mark on the yellow Post-It than on the dark blue tape.

You don’t need a computer for these steps, just keep the stepper motors off and move the table by hand. When it comes time to fire the laser, you just have to tap the test button on the front panel.
The first thing to align is the tube itself. My tube was so far out of alignment that the beam wasn’t even hitting the mirror. The tube is held in with two metal spring straps. Rubber rings keep the straps from breaking the glass tube. More rubber acts as shims to align the tube vertically. I removed one of the shims from the left side of the tube and added it to the right. It’s a fiddly procedure since tightening too hard on the screws will break the single most expensive part of the K40 – the laser tube.

I found that even after an alignment, my K40 still wasn’t performing correctly. I cleaned the mirrors and the laser tube with alcohol, but it was no help. Finally, I disassembled the focusing head. That’s where I found my problem. There were bits of metal inside the head from when it was machined. These metal pieces were in the beam path, disrupting it. I took the 45-degree mirror and the focusing lens out, then carefully cleaned the tube. Once everything was re-assembled, my K40 was ready for action.

Software

The laser comes with an obviously burned CD and a USB stick. My laptop doesn’t have a CD drive, so I popped in the USB stick and found… nothing. It’s not really a drive, but a dongle to unlock the laser driver software. I had to go and find my USB cd drive before using the K40. Most of the filenames on the disc are in Chinese. Some digging eventually led me to a file for Corel Laser. It’s a copy of Corel Draw with a plugin to drive the K40. The copy of Corel Draw is almost certainly an illegal cracked copy. I got access to a legit base copy from a friend who switched over to Adobe.

In simple terms, CorelLaser gives you a toolbar and can cut or engrave any image loaded into Corel Draw. Cutting and engraving are very different processes though. Cutting is a vector operation. The laser will trace the path of every line in the image. Engraving is a raster affair. The laser will draw the image line by line, left to right and top to bottom. You can also perform both processes on the same design by creating a cut layer and an engraving layer in the software.

I ran into trouble with the software pretty quickly. Whenever I tried to cut, the laser head moved slowly. Changing the movement settings didn’t help. Some digging eventually pointed me to the settings page for CorelLaser. Here I found the “mainboard” setting was wrong. The value has to match the model number silk screened on the laser mainboard. Of course, the mainboard is mounted in such a way that you can’t read the model number, but a quick cell phone photo fixed that problem. My model is 6C6879-LASER-M2. The board firmware is dated 2018-01-08, so the board must have been built sometime after that.

I expected CorelLaser to be a hot mess. Honestly, it isn’t half bad. It definitely has some maddening quirks, but overall it does what it should – drive the steppers and switch the laser. The top quirk I’ve found is line width. Corel defaults to “hairline” as line width. This is larger than the laser kerf, so CorelLaser interprets it as two parallel paths. Tracing two close paths on with the K40 will make a wide burning mess of whatever you’re trying to cut. The solution is to select everything in your document <Ctrl-A> then hit F12, and change the line width to .001 mm. CorelLaser will then operate as you expect it to.

Which Materials to use (and which to avoid)

What to cut? As with any laser cutter, thought has to be given to the materials being cut. In general, wood is safe to cut, as is paper, cloth, melamine, pressboard, matte board, cork, some rubbers, natural leather, and Corian. Engraving can be performed on materials such as glass, stone, anodized aluminum, steel (with a laser engraving coating) and other materials.

Some plastics should never be cut in a laser cutter. Anything with chlorine – notably PVC and vinyl. Burning PVC results in chlorine gas, which will kill the user, and hydrochloric acid, which will rust your K40 out so bad that your next of kin won’t be able to enjoy it. A simple test for chlorine is the copper wire burnination test, which can be seen in this 10-year-old video from [Adam] and [Zach] at NYC Resistor. ABS plastic is another one to avoid. It tends to melt and is messy to cut. It also releases trace amounts of cyanide gas. If you’re ever unsure about a material, look up on the pages of hackerspaces who have lasers. If they won’t cut it on their laser, you probably shouldn’t either.

Cutting and Engraving

Cutting and engraving are what we’re all here for, right? The fun part of learning the laser is figuring out how to set up the software for different materials. With a laser, you have three variables to play with. Laser power, speed, and the number of passes. Laser power is controlled by the front panel of the K40. It’s either a knob and an inaccurate milliampere meter or a digital control expressed in power percentage. Cutting with more than one pass is messier than just cutting the material once, so save that for when you really need to do it.

There are a few guides out there – I’ve found this page to be a good starting point for figuring out which speeds and power levels to run at for a given material. I generally will use the speed from that site, then start at a much lower laser power. Testing on scrap pieces, I’ll keep raising the power until I have a clean cut. If the power is below 50%, I’ll generally stick with it, and not adjust the speed.

You should definitely keep notes of what you use. On my laser, I found a deep engrave on ⅛” acrylic at 50% and 320 mm/s. Cutting ⅛” birch plywood worked best at 25% power and 5 mm/s. Keep in mind that quality control on the K40 is non-existent, and beam focus will matter, so your device may be different from mine. Further, materials such as plywood and acrylic can change from batch to batch depending on moisture content and other variables. Always buy some extra material to use as scrap for dialing in your settings.

Performance

So how good is the K40 in a “bone stock” condition? Pretty damn good actually. I was able to cut ⅛” birch plywood and ⅛” acrylic with one pass at less than 50% power. The parts would literally fall out as each cut complete. This is a laser, so of course, there is some charring of the wood on the edges, but nothing a bit of sandpaper can’t fix. As a torture test, I took the Hackaday logo .svg file loaded it up into CorelLaser, set the line width to .001 mm, and hit go. The K40 dutifully cut out the jolly wrencher, giving me a little puzzle of pieces to try to fit back together.
Engraving performance was good too – I was able to cut simple black and white images (and text) into wood and acrylic. I can see how this would be perfect for making control panels with labeled lights and switches.

Summary

The K40 is a cheap laser engraver/cutter. However, it is very capable, even when used unmodified. That said, the cutter is a great platform for modification. You can bet I’ll be spending some time adding things like air assist and a better bed to my K40 as well as cutting down that exhaust duct.

Kipp Bradford on the Importance of Boring Projects, Medical Tech, and Sci Fi Novels

พฤ, 09/27/2018 - 23:01

If someone suggests you spend time working on boring projects, would you take that advice? In this case, I think Kipp Bradford is spot on. We sat down together at the Hackaday Superconference last fall and talked about medical device engineering, the infrastructure in your home, applying Sci-Fi to engineering, and yes, we spoke about boring projects.

Kipp presented a talk on Devices for Controlling Climates at Supercon last year. It could be argued that this is one of those boring topics, but very quickly you begin to grasp how vitally important it is. Think about how many buildings on your street have a heating or cooling system in them. Now zoom out in your mind several times to neighborhood, city, state, and country level. How much impact will a small leap forward have when multiplied up?

The next Hackaday Superconference is just around the corner. Before you join us below for the interview with Kipp, make sure you grab your 2018 Hackaday Superconference ticket to be there for great talks like Kipp’s!

When we sat down for an interview, we dug a little deeper into the “boring” projects that Kipp Bradford sees as important. HVAC has already been mentioned, but he adds to that things like electrical infrastructure, concrete (think construction), and plumbing. At first glance these don’t feel flashy like the latest and greatest smart watch design. But they affect a mindbogglingly enormous portion of humanity. Start looking around and you’ll easily appreciate Kipp’s point of view. Boring things are everywhere, and they’re begging for a new set of eyes to move them forward.

If you just can’t get excited about the infrastructure, there’s still hope. We touched on the difficulty of getting medical equipment through the regulatory process — a realm where Kipp has breadth of experience. It’s interesting to hear his views on the opening up of what has been a closed area. Specifically he mentions hearing aids and electrocardiograms (ECG). Kip cites HeartyPatch from last year’s Hackaday Prize as a great example of progress — what once was prohibitively expensive is now available in a chip for anyone to experiment with. He sees additional opportunities opening now in places like hearing aid technology as the supply chain and regulatory process both become easier to navigate.

I like the message that Kipp leaves us with: “The imagination has to be at 20, not 10, not 11… 20!”. As with so many brilliant people, Kipp found he was working during all waking hours and it took a toll on his creativity. He turned to Sci Fi literature as an outlet and found it to be exactly what he needed. For him, these books helped him envision many possible futures, which is the first step in going out and making those futures happen.

Want to hang out with hundreds of awesome people like Kipp Bradford? The place to do it is at the Hackaday Superconference!

The New, Improved Open Hardware Certification Program

พฤ, 09/27/2018 - 22:01

Today at the Open Hardware Summit at MIT, OSHWA, the Open Source Hardware Association has announced a huge revision to the Open Hardware certification process. The goal here is to design a better platform for creating Open Hardware.

While all hardware already certified as Open Hardware will remain Open Hardware, this revamp of the ‘hub’ of the certification process is greatly improved. There’s a new website. There are learning modules telling everyone what it means to be Open Source hardware. There are community examples — real-life walk-throughs of projects that have already been created. There’s a streamlined certification process, and an improved listing of Open Hardware projects.

But Why A Certification Program?

While Open Source in the world of software is easily defined, it is effectively a hack of copyright law; all software is closed by default, and an Open Source software license is merely that; a license for anyone to use it, with the various restrictions and philosophical battles. Hardware, on the other hand, is big-O Open by default. The code used to program an FPGA is covered by copyright, but the circuit itself isn’t. The firmware on your Arduino project is covered by Open Source software licenses, but the physical implementation of your Fritzing picture isn’t.

In the absence of a legal framework to truly make an Open Hardware license work, the only other option is a certification program. The current Open Source Hardware certification program launched in 2016, and has since seen hundreds of projects certified from dozens of countries. It is, by any measure, a remarkable success. The people who make hardware are certifying that their work complies with community-set standards, and all of these projects are registered.

The New, Improved Interface for the Certification Program

While the core of the Open Hardware Certification program hasn’t changed, the user interface — the ‘killer app’ of a directory of Open Hardware projects — has. According to the press release put out by OSHWA ahead of the announcement, “The revamped website consolidates a broad range of information about open source hardware onto a single site. To maximize comprehension for people pursuing certification for their own hardware, important documentation and licensing concepts are illustrated with specific existing examples from the registry. An improved directory and search function makes it easy to find hardware that matches a broad range of criteria.”

Compared to last week’s version of OSHWA’s website, this is a huge improvement. Now, you can easily find information about what it means to make Open Hardware. The complete directory of Open Hardware projects isn’t just a spreadsheet on a webpage anymore, you can actually search for projects now. This is a huge improvement to the Open Hardware certification program, and we can’t wait to see how this new platform will be used.

You can check out the rest of the Open Hardware Summit over on the livestream.

Can You “Take Back” Open Source Code?

พฤ, 09/27/2018 - 21:00

It seems a simple enough concept for anyone who’s spent some time hacking on open source code: once you release something as open source, it’s open for good. Sure the developer might decide that future versions of the project close up the source, it’s been known to happen occasionally, but what’s already out there publicly can never be recalled. The Internet doesn’t have a “Delete” button, and once you’ve published your source code and let potentially millions of people download it, there’s no putting the Genie back in the bottle.

But what happens if there are extenuating circumstances? What if the project turns into something you no longer want to be a part of? Perhaps you submitted your code to a project with a specific understanding of how it was to be used, and then the rules changed. Or maybe you’ve been personally banned from a project, and yet the maintainers of said project have no problem letting your sizable code contributions stick around even after you’ve been kicked to the curb?

Due to what some perceive as a forced change in the Linux Code of Conduct, these are the questions being asked by some of the developers of the world’s preeminent open source project. It’s a situation which the open source community has rarely had to deal with, and certainly never on a project of this magnitude.

Is it truly possible to “take back” source code submitted to a project that’s released under a free and open source license such as the GPL? If so, what are the ramifications? What happens if it’s determined that the literally billions of devices running the Linux kernel are doing so in violation of a single developer’s copyright? These questions are of grave importance to the Internet and arguably our way of life. But the answers aren’t as easy to come by as you might think.

Copyleft and Ownership

The GPL is what’s known as a copyleft license, which is designed to add additional rights for the end users which would otherwise be limited by copyright laws. For example, it gives the user the right to duplicate and create derivative works. But an important distinction is that copyleft licences such as the GPL don’t actually replace the original copyright, they are merely supplemental. The original author of the code still holds the copyright, and is ultimately its sole owner.

This allows for the concept of dual licensing: wherein the sole author of a program can chose to license a program under multiple licenses at the same time, one of which generally being more permissive than the other. For example, the Windows version of a program could be closed source, while the Linux version is open source; even if the actual code is identical. More often, this is used to provide one license that applies for commercial use of a program, and more permissive licensing for individuals.

Some open source projects, generally large ones with corporate backing, occasionally have what’s known as a Contributor License Agreement. This document explains any additional requirements and rules for submitting source code to a project, and will usually have a clause explaining that the submitter is granting their copyright to the project’s parent entity. For example, here is the relevant section from Google’s “Individual Contributor License Agreement”:

Subject to the terms and conditions of this Agreement, You hereby grant to Google and to recipients of software distributed by Google a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Your Contributions and such derivative works.

It’s worth noting that Linux does not utilize such an agreement, and the copyright for any submitted source code therefore remains the property of the original developer.

Reputational Losses

So if a developer is free to license their code in diametrically opposed ways (simultaneously closed and open source), and it’s acknowledged that in the absence of a Contributor License Agreement they retain the uncontested ownership of any code they write, the situation becomes tricky. Does it not follow that they have the right to walk back a promise to make their source code open, if a scenario presents itself in which the author feels it’s no longer appropriate?

Eric S. Raymond

Eric S. Raymond, one of the founders of the Open Source Initiative and author of The Cathedral and the Bazaar believes they may have that right. In a post to the Linux Kernel Mailing list, Eric specifically addresses the threat some developers have made about attempting to pull their code from the kernel:

First, let me confirm that this threat has teeth. I researched the relevant law when I was founding the Open Source Initiative. In the U.S. there is case law confirming that reputational losses relating to conversion of the rights of a contributor to a GPLed project are judicable in law. I do not know the case law outside the U.S., but in countries observing the Berne Convention without the U.S.’s opt-out of the “moral rights” clause, that clause probably gives the objectors an even stronger case.

Section 6 of the Berne Convention explains that the original author of a work, even if they have granted their rights to another entity, can object to its further use if they feel it has been utilized in a way which “would be prejudicial to his honor or reputation.” So in theory a disgruntled developer need only convince a judge that the maintainers of a project have damaged their reputation, say by publicly banning them for violating the Code of Conduct, and have a case for forcing the project to stop using their code regardless of preexisting licensing agreements.

Critical Language

But the question remains, can a developer actually “revoke” the rights given under the GPL? If we’re talking about the GPLv2 (which Linux is licensed under), the closest thing we find is Section 4:

However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

Interestingly, if we take a look at the GPLv3, we see relevant language was made much stronger:

All rights granted under this License are granted for the term of copyright on the Program, and are irrevocable provided the stated conditions are met.

Some believe the distinction here may prove to be critical. In a legal context, it’s generally understood that “revoke” means an agreement was retracted by the entity offering it (here, the original developer), while “terminate” simply means to end an agreement. This leaves room for interpretation, and one could potentially argue that since the GPLv2 does not specifically state the developer can’t retract the offer, it remains an option.

Here Be Dragons

Between the Eric S. Raymond’s assertion that a developer could claim divisive elements within the project are damaging to their reputation and the fact that the current licensing arrangement of Linux means there’s no specific language saying developers can’t withdraw their submissions, the situation becomes murky. The truth is, nobody is really sure yet. We’re in uncharted waters, and old assumptions may not hold up to legal scrutiny if it comes to it.

It’s also worth mentioning that the concept of “Promissory Estoppel” could come into play; which essentially prevents an individual from going back on a promise if the other party took action based on that promise. In other words, if you told somebody they could use your code and they used it to produce a successful project, you can’t then go back on that promise because it would be to their detriment.

Practically speaking, even if an individual built a case saying they wanted their chunk of code removed from Linux, it would be physically impossible. In lieu of being able to delete their code from the now-copyright-infringing devices, said developer would likely receive some monetary settlement. Which would still be a terrible precedent to set for the open source community: get mad, get paid.

At the end of the day, talk of revoking open source licenses is misguided. To paraphrase the character of Ian Malcolm from Jurassic Park: angry developers are so preoccupied with whether or not they could, they haven’t stopped to think if they should. If legal precedent is set that a developer can take their source code back, it will be ruinous to the open source community. Its taken decades for free and open source software to rise to its current prominence in the software world, but the rash actions of a few unhappy developers could be enough to drag it back down to being little more than a wishful idea.

The Exquisite Badges Of Open Hardware Summit

พฤ, 09/27/2018 - 18:40

The past few years have been all about electronic conference badges and this year is no different. Right now, we’re setting up at the Open Hardware Summit at MIT, and this year’s badge is nothing short of extraordinary. It’s a WiFi and Bluetooth-enabled e-paper badge, individually programmed for every attendee. The 2018 Open Hardware Summit badge is a work of art, and it was all created over on hackaday.io.

This board is based on the ESP trINKet designed by [Mike Rankin] with additional hardware design from [Alex Camilo]. The badge is based around the ESP32-wroom-32 module with a 2.13 inch e-paper display with a resolution of 250 x 122 pixels. To this, the badge adds an I2C accelerometer and support for add-ons. There’s also pads for an SD card holder — a soldering challenge, if you will — and few additional pads for bits and bobs.

But a badge is nothing without software, and that’s where this really gets good. The ESP32 module is a powerhouse, capable of emulating NES games or serving as a file server. Here, the stock configuration of the badge is rather simplistic: you can start a WiFi AP, log onto a web page, and change the name displayed on the badge. You can also start an FTP server, which is where things get really fun. Drop an application on that FTP server, and you can run Micro Python.

The badge is great, but the programming jig is awesome

The boards were made through OSH Park, and Screaming Circuits took care of the assembly. Anyone who has ever built a badge will tell you it isn’t the assembly that gets you — it’s the programming and provisioning. This is especially true since the Open Hardware Summit badge is distributed with the attendee’s names already preloaded. That’s a few hundred badges, all with unique firmware. This is a nightmare by any definition.

However, there’s always a good solution to a problem, and [Drew] from OSH Park showed me the best programming jig I’ve ever seen during the Summit pre-game at Artisan’s Asylum.

What you’re looking at is a 3D printed box loaded up with a touch-screen display, a Raspberry Pi Zero W, and a few pogo pins. This Raspberry Pi does all the heavy lifting by connecting to the Internet, pulling down the current version of the firmware, and loading that firmware onto the badge. There are a few more options thanks to the touch-screen interface, including provisioning all the badges with the names of the attendees — this can be done by reading a list of attendees and uploading the next one to the badge in the jig. All of this is wrapped up with a nice laser-cut cover that securely holds each badge exactly where it needs to be for the pogo pins to make contact.

This is, without question, the best programming jig I’ve seen. Any badge makers out there should take note: this is how you program a few hundred badges. The badge, itself, is great and just as this post is published there will be hundreds of eager hackers futzing about with this remarkable piece of hardware. If you want to check out the current progress of the badge hacking, check out the updates on Twitter

Maker Faire NY: Infinite Autonomous 3D Printing

พฤ, 09/27/2018 - 18:00

Although it’s not an idea that has yet trickled down to $200 printers drop-shipped from China, one of the most innovative ideas in the 3D printing world in the last few years is putting plastic down on a conveyor belt. Yes, MakerBot was doing it back in 2010, but we’re not going to talk about that. Printing on a conveyor belt instead of a static bed allows you to easily print multiples of an object autonomously, without any human interaction. If you’re really clever, you could rotate the hot end 45° and build a piece of plastic that is infinitely long, like the printer [Bill Steele] built, the Blackbelt, or ‘the CAD files might exist somewhere’ Printrbot infinite build volume printer.

At this year’s World Maker Faire, we didn’t see an infinite printer, but we did catch a glimpse of an idea that could reliably take 3D printers into production. It’s a Multiprinter Autonomous 3D Printer, designed and built by [Thomas Vagnini].

The idea of using 3D printers for production and manufacturing is a well-studied problem. Lulzbot has a heated room filled with printers they use to manufacture all their machines. Prusa’s manufacturing facility is similarly well-equipped. However, both of these setups require helper monkeys to remove a part from the bed and set the machine up for the next print.

Instead of a strictly manual process, [Thomas]’ machine uses a sort of cartridge-based system for the printing bed. The glass beds are stored in a cassette, and for the first print, the printer pulls a bed onto the heated build plate through a system of conveyors. When the print is finished, the part and the bed ar fed into a rotating cassette, where it can be removed by a tech, prepped for the next print, and placed back in the ‘bed feeder’. It’s a system that brings the manual intervention cycle time of a 3D printer down to zero. If you’re producing hundreds of parts, this will drastically speed up manufacturing.

While it is a relatively niche idea, this is a very well-designed machine. It’s all laser cut, uses core-XY mechanics, and with the right amount of tuning, it does exactly what it says it will do. It’s not for everybody, but that’s sort of the point of manufacturing parts on a 3D printer.

Fallout Watch Build Triumphs In Adverse Conditions

พฤ, 09/27/2018 - 15:00

Is it a badge? Is it a watch? Well, it’s [Sarif’s] take on a wrist-mounted computer from the Fallout series, so you’re free to choose your own designation! We think the Brotherhood of Steel would be proud to have this piece of kit.

[Sarif] commenced the build after first getting their feet wet with the pipman, a watch inspired by Metro 2033 and Steins;;gate as much as Bethesda’s popular post-apocalyptic RPG. It features all the fruit – GPS, compass, a TV-B-Gone – and perhaps the coolest feature, long-since-deprecated bubble LED displays and flippy switches for that Altair-esque charm.

The build log is full of details, from the components used and the debugging battles involved in the journey. [Sarif] learned about using transistors, burning up a few along the way – some say setting the lab on fire is the quickest way to learn important lessons, anyway. On top of that, there were some software niggles but in the end, the watchputer made it to DEFCON 26 anyway!

Builds like this that start from limited experience and go deep into the trials and tribulations involved are an excellent way to learn about what goes into the average DIY electronics project, particularly when talking about embedded systems. And if you’re keen to check out the work of [Sarif’s] contemporaries, we’ve got a collection of all the awesome badges from DEFCON 26. Enjoy!

Epoxy Fix For A Combusted PCB

พฤ, 09/27/2018 - 12:00

When the Magic Smoke is released, chances are pretty good that you’ve got some component-level diagnosis to do. It’s usually not that hard to find the faulty part, charred and crusty as it likely appears. In that case, some snips, a new non-crusty part, and a little solder are usually enough to get you back in business.

But what if the smoke came not from a component but from the PCB itself? [Happymacer] chanced upon this sorry situation in a power supply for an electric gate opener. Basking in the Australian sunshine for a few years, the opener started acting fussy at first, then not acting at all. Inspection of its innards revealed that some unlucky ants had shorted across line and neutral on the power supply board, which burned not only the traces but the FR4 of the board as well. Rather than replace the entire board, [Happymacer] carefully removed the carbonized (and therefore conductive) fiberglass and resin, leaving a gaping hole in the board. He fastened a patch for the hole from some epoxy glue; Araldite is the brand he used, but any two-part epoxy, like JB Weld, should work. One side of the hole was covered with tape and the epoxy was smeared into the hole, and after a week of curing and a little cleanup, it was ready for duty. The components were placed into freshly drilled holes, missing traces were replaced with wire, and it seems to be working fine.

This seems like a great tip to keep in mind for when catastrophe strikes your boards. There are more extreme ways to do it, of course, but perhaps none so flexible. After all, epoxy is versatile stuff.

Learn Verilog In Your Browser

พฤ, 09/27/2018 - 09:00

We are big fans of tools in the browser for education. You have a consistent environment maintained by someone else, you don’t have to install anything, and you can work from any computer you happen to find yourself. The HDLBits site has a great set of Verilog “exams” that would be a big help to anyone trying to learn or brush up on their Verilog skills.

The site offers a range of topics that go from the silly (output a constant 1 or 0) to full-blown state machines and testbenches. The site isn’t tutorial in nature, instead it offers a problem, an optional hint, and an editing window with some code already in place. You add your code and hit submit. Behind the scenes, the site runs Intel Quartus and Modelsim to test your work. It will either show you the results or tell you that you failed.

We’ve been big fans of EDA Playground which offers a nice environment for experimenting with FPGA code, but it doesn’t challenge you the way this does with a series of progressively more difficult exercises, either. Of course, that’s still a great tool if you want to experiment with your own designs. If you prefer, the HDLBits site will let you do a simple simulation using Icarus, but it isn’t nearly as full-featured as EDA Playground.

If you are adept at Verilog, you are able to jump to any of the exercises that interest you. Some of the later ones do sort of build on each other, but you can always backtrack if you get in trouble. If you like stats or competition, the site offers statistics on how many users have attempted each problem and their success rate. There’s also a user ranking board that rolls every six months. The top of that board, [wg250785453] solved 178 of the problems, which we think may be all of them.

The site is part of a family of sites. There’s also ASMBits which is the same sort of thing for Nios II or ARMv7 assembly language. You can also find a generic simulator and debugger for Nios II, ARMv7, and MIPS32 at their cpulator site.

This is a great time to be working with FPGAs. We are hopeful that the new FPGA-bearing Arduino will eventually give us full access to its internals and then we should really see some momentum building.

Apple’s Best Computer Gets WiFi

พฤ, 09/27/2018 - 06:00

The greatest computer Apple will ever make isn’t the Apple II, it isn’t the Bondi Blue iMac, it isn’t the trash can, and it certainly isn’t whatever overheating mess they’re pushing out now. The best computer Apple will ever make is the SE/30, at its time a server in a tiny portable shell, and capable of supporting 128 Megabytes of RAM thirty years ago.

Over the years, people have extended and expanded the SE/30 to absolutely ludicrous degrees, but now we have a simple way of adding WiFi to this classic computer. Over on the 68kmla forums, [ants] discovered a tiny cheap card that could easily serve as an Ethernet to WiFi bridge. After attaching this card to a Danaport Ethernet card and bending some aluminum for a bracket, they had a WiFi antenna sticking out of the back of a 30-year-old computer.

But adding a WiFi card to an old computer is nothing new — this could have been done with a Pi, or if you’re a hacker, a TP-Link router flashed with OpenWRT. To really do this right, you’ll need integration with the operating system, and that’s where this build goes off the rails. [ants] wrote a WiFi extension for System 7 (with the relevant GitHub)

The problem with the Vonets WiFi card is that configuration has to be done through a browser. Since there are no modern browsers for classic macs, this meant either pulling out a PowerBook or doing the configuration through your daily driver desktop PC. The WiFi extension gets around that by giving a classic mac the ability to configure the Vonets card almost automatically. This extension also looks like how you would configure the WiFi on a modern mac, complete with the WiFi icon in the toolbar. It’s beautiful, and one of the rare examples of modern 68k mac programming.

As for what you can do by adding WiFi to a 30-year-old computer with a 16MHz processor, the answer is a resounding, ‘not much’. Your choice of browsers is limited (iCab seems to be the best), but you can load the Google homepage slowly. HTTPS isn’t going to work, and the Internet right now is full of megabytes of Javascript cruft. If you find a nice, lightweight web page — such as the Hackaday Retro Edition, for example — you’re looking at a capable web browsing machine. Of course, the real use case for giving the SE/30 WiFi is file transfer around the home network, but still: it’s WiFi for the best computer Apple ever made.

Bask In The Warm Glow Of DIY Incandescent Bulbs

พฤ, 09/27/2018 - 03:00

With most of the apparatus and instruments we now take for granted yet to be developed, the early pioneers of the Electric Age had to bring a lot to the lab besides electrical skills. Machining, chemistry, and metallurgy were all basic skills that the inventor either had to have or hire in. Most of these skills still have currency of course, but one that was once crucial – glassblowing – has sadly fallen into relative obscurity.

There are still practitioners of course, like [2SC1815] who is learning how to make homemade incandescent light bulbs. The Instructable is in both English and Japanese, and the process is explained in some detail. Basic supplies include soda-lime glass tubing and pre-coiled tungsten filaments. Support wires are made from Dumet, an alloy of iron, nickel, and cobalt with an oxidized copper cladding which forms a vacuum-tight seal with molten glass. The filament is crimped to the Dumet leads and pinched into a stem of glass tubing. A bulb is blown in another piece of tubing and the two are welded together, evacuated with a vacuum pump, and sealed. The bulbs are baked after sealing to drive off any remaining water vapor. The resulting bulbs have a cheery glow and a rustic look that we really like.

Of course, it’s not a huge leap from DIY light bulbs to making your own vacuum tubes. That’s how [Dalibor Farny] got started on his handmade Nixie business, after all.

Hair Is Good Electronic Hub Real Estate

พฤ, 09/27/2018 - 01:31

When it comes to wearables, there are a few places you can mount rechargeable batteries and largish circuit boards. Certainly, badges hanging from a lanyard are a favorite here on Hackaday. A belt is another option. [deshipu] has come up with a good location on your head, provided you have long hair that is. That’s the hair clasp or barrette. It can support a hefty mass, be relatively large, and doesn’t touch your skin.

His plan gets even better, namely to use it as a hub for other electronics on your head, giving as examples: mechatronic ears and LEDs on eyelashes, earrings, and neck collars. We’d include some sort of heads-up display on glasses too or perhaps some playful glasses windshield wipers.

Being able to solder the clasp to the circuit board was his first success and he’s since made a test barrette with pulsing LEDs which he’s distributed to others for evaluation. We really like his electronic hub idea and look forward to seeing where he takes it. For now, he’s done enough to have become a finalist in the Hackaday Human Computer Interface Challenge.

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Building a Hardware Store Faraday Cage

พฤ, 09/27/2018 - 00:01

Most Hackaday readers are no doubt familiar with the Faraday cage, at least in name, and nearly everyone owns one: if you’ve ever stood watching a bag of popcorn slowly revolve inside of a microwave, you’be seen Michael Faraday’s 1836 invention in action. Yet despite being such a well known device, the average hacker still doesn’t have one in their arsenal. But why?

It could be that there’s a certain mystique about Faraday cages, an assumption that their construction requires techniques or materials outside the realm of the home hacker. While it’s true that building a perfect Faraday cage for a given frequency involves math and careful attention to detail, putting together a simple model for general purpose use and experimentation turns out to be quick and easy.

As an exercise in minimalist hacking I recently built a basic Faraday cage out of materials sourced from Home Depot, and thought it would be interesting to not only describe its construction but give some ideas as to how one can put it to practical use in the home lab. While it’s hardly a perfect specimen, it clearly works, and it didn’t take anything that can’t be sourced locally pretty much anywhere in the world.

Faraday Cage Design

At the most basic level, a Faraday cage is an enclosure made of a conductive material that blocks electromagnetic fields. In comparison to a Faraday shield, the cage variant is not a solid object, but rather a metallic mesh. Among other advantages, this allows observation of the subject inside of the cage. Put simply: if you simply want to protect a device from interference (or prevent it from causing interference) then it’s enough to enclose it in a metal box; but if you want something that you can experiment with, you’ll probably want a cage.

The trick is to make sure the holes in the cage material are smaller than the wavelength you wish to block. It’s the same principle that allows you to use standard chicken wire as a RF reflector as long as you’re working with relatively low frequencies. But as your target frequency increases the wavelength gets small enough that it can sneak through chicken wire, so you need to use something tighter. But how small is small enough?

To start, we need to find the wavelength for the frequency we want to block. This can be found by dividing the wave’s speed in meters per second by its frequency in hertz. As we’re dealing with a radio wave we know it will be traveling at the speed of light, and for the frequency let’s say we want to block 2.4GHz. So the math will look like:

The rule of thumb for a Faraday cage is that the openings should be no larger than 1/10th of the wavelength, which in our case is 12.5 mm (approximately 1/2 inch). As luck would have it, steel “hardware cloth” with mesh sizes of 1/2″ and 1/4″ is widely available. On paper either should work, but I did end up going with the 1/4″ to be safe.

Construction

With the mesh in hand, the next step is to build some kind of frame for it. As it so happens, Home Depot has wooden crates in their storage section which are strong and relatively cheap. You could also construct a frame from pieces of wood or PVC pipe, which may end up being cheaper if you don’t mind taking the time to build it.

I popped a couple of the slats out of one side of the crate so it would be easier to see inside, but beyond that, the construction simply consists of wrapping the crate with the hardware cloth. I did one long piece that started at the front and wrapped all the way to the back, and then two smaller pieces to “cap” the sides. In the end, it’s not entirely unlike gift wrapping; if the gift wrap was metal and had a nasty tendency to cut you, anyway.

One thing to pay close attention to is where pieces of the mesh overlap. You want to maintain a good electrical connection and avoid any gaps, so you should overlap the pieces by at least a couple of inches to be safe. I attached the hardware cloth to the crate with a power stapler, so I also made sure to drive a few extra staples through the areas where the mesh overlapped to ensure they were held together tightly.

Testing

As a simple test, I set my phone up on the bench running the signal strength function of the “WiFi Analyzer” application for Android, with an Access Point that’s one floor above selected as the target. In the two pictures below, the only thing that has changed from one shot to the other is placing the DIY Faraday cage over the phone.

As you can see, the phone had a signal strength of approximately -55dBm originally, and it dropped down to nearly -80dBm when inside the cage. Weaker Wi-Fi networks were rendered undetectable when the phone was inside the cage, and there was a clearly detrimental effect on the phone’s LTE reception.

Flawed Design

I should say, before the commenters below get a chance to do it for me, that this is admittedly not a very good Faraday cage. For one, it’s not fully enclosed. Since there’s no bottom signals are still able to enter from below, greatly reducing its effectiveness. The steel mesh is also not an ideal conductor, and copper would likely work better. But finding a local source of tightly wound copper mesh proved tricky.

There’s also some debate about whether a Faraday cage must be grounded or not. For what it’s worth, during my testing there was no observable change in performance when the cage was grounded. Though it’s possible a more conventional Faraday cage may perform differently.

Having said that, I still feel this design blocks RF enough to be useful. It will never completely isolate the device inside from electromagnetic interference (or vice versa), but it attenuates signals significantly enough to be clearly observable. That was the extent of my ambition to begin with, so I’m happy with the results.

Possible Applications

Imagine you are developing or testing a remotely controlled device, and want to see how it behaves when signal strength is poor. Tossing the cage over it would allow you to induce a drop in signal strength instantaneously. Or perhaps you’re observing the RF emissions of a device, but want to cut-down on superfluous background noise. Putting the piece of gear under test and your SDR hardware inside the cage would be an easy way to study it in a less “noisy” environment.

Those are just two possibilities. This demonstration shows there’s really no good reason not to have a simple RF blocking device at your disposal. It’s cheap, it works, and it can be your next weekend project. What you do with it is up to you, just make sure you drop us a line when you figure it out. What would/do you use a Faraday cage for?

Bring Your Own Controller Kits Just Add Bluetooth

พุธ, 09/26/2018 - 22:30

Known for their build quality and low latency, the [8bitdo] line of Bluetooth controllers are generally well liked among classic videogame devotees. They match modern conveniences like rechargeable batteries and Bluetooth connectivity with old school color schemes and the tried-and-true feel of a D-pad. All of their current offerings are modeled to invoke the same feel of console controllers of the past, however, for some there is no substitute for the original. For that type of hobbyist, the company created DIY Bluetooth mod kits in the form of drop-in replacement PCBs.

The featured mod kits are for the original NES controller, SNES controller, and 6-button Genesis Controller. They feature a 180 mAh Li-ion battery for an estimated 7.5 hours of gameplay, and a unique barrel plug type USB charging cable. The charging port fills the void left by the controller’s connection cable and also doubles a the LED status indicator. Though for the Sega Genesis mod kit, the charge port changes to a standard micro USB.

The [8bitdo] website boasts compatibility across Android, Linux, Mac, and Windows (drivers permitting) and even Nintendo Switch. With the addition of one of the company’s Retro Receivers, you are able to use the controllers on the original NES or SNES alongside their contemporary NES/SNES classic console counterparts.

So now you can play all those vintage games wirelessly without the need for direct line-of-sight like the old infrared controllers of the 90s. The whole installation process for the PCB is further simplified, because the [8bitdo] mod kits even provide the screwdriver…how thoughtful.

For a more bespoke approach to adding Bluetooth to a classic controller, check out this NES controller mod. Or check out 8bitdo’s tutorial video for the NES Original mod kit:

Hack My House: Raspberry Pi as Infrastructure

พุธ, 09/26/2018 - 21:01

I finally had my own house. It was a repossession, and I bought it for a song. What was supposed to be a quick remodel quickly turned into the removal of most of the drywall in the house. There was a silver lining on this cloud of drywall dust and loose insulation. Rather than constantly retro-fitting cabling and gadgets in as needed, I could install everything ahead of time. A blank canvas, when the size of a house, can overwhelm a hacker. I’ve spent hours thinking through the infrastructure of my house, and many times I’ve wished for a guide written from a hacker’s perspective. This is that guide, or at least the start of it.

What do you want your smart house to do? And what do you want to be able to do in your smart house? For example, I wanted to be able to upgrade my cheap 120 V welder to a beefier 240 V model, so adding a 240 V plug in the garage was a must. As a bonus, that same 240 V circuit could be used for charging an electric car, if ever one is parked there.

“Ethernet everywhere” was my mantra. Try to imagine everywhere you might want to plug in a desktop, a laptop, an access point, or even a VoIP phone. I decided I wanted at least two Ethernet drops to each room, and tried to imagine the furniture layout in order to put them in convenient places.

The problem is that not everything uses Ethernet. I wanted temperature sensors, magnetic switches on the doors– Oh, and tie into the HVAC control, and maybe a webcam or a motion detector. Add in LEDs and relays for controlling lights, and it becomes obvious that a better solution is needed.

Pi Boxes

I’ve always been fond of the Raspberry Pi– It has USB, GPIO, and i2c, among other interfaces. An Instructable by [peter_3d] gave me the burst of inspiration I needed. A 3-gang electric box is the perfect size for a Raspberry pi. The newest version of the Pi, the Pi 3 b+ has support for a PoE hat, which we’ve recently covered.

In each room of the house, I’ve mounted an electric box in the ceiling, as well as on the wall of the central hallway. To each box, a single Ethernet cable runs back to a central point in the room destined to be my home office. Each Pi will sit on a 3-wide blank plate. From each of these points, I can eventually mount a thermal and humidity sensor, a webcam, a motion detector, or any number of other sensors. The unit in the hallway wall will get the full touchscreen treatment.

A smart, PoE capable switch will power this web, and a flask instance providing a RESTful interface will allow pulling the data back to a central controller, as well as pushing commands back to the nodes. [Matt Richardson] was part of the inspiration, and has a very good primer on the subject. A central web interface can then track temperatures, control the heater and air conditioner, and monitor doors opening and closing.

One of my longstanding complaints about the Raspberry Pi is that power instability kills SD cards. Starting with version 3, the Pi supports booting over a network without an SD card. Rather than running to each device for maintenance (fsck the sdcard), all the file-systems can live on a central server, and are mounted over NFS. There is enough to the process of setting up PXE boot for the Raspberry Pi, it deserves a dedicated article.

I have further plans for my house, and the Raspberry Pi is an excellent platform to expand upon in the future. Next time, we’ll talk more about structured cabling, security cameras, and whatever else you want to hear about. Let me know below!

Adding Analog Touch To (Nearly) Any Mechanical Keyboard

พุธ, 09/26/2018 - 18:00

The new hotness for DIY electronics is mechanical keyboards, and over the past few years we’ve seen some amazing innovations. This one is something different. It adds an analog sensor to nearly any mechanical key switch, does it with a minimal number of parts, and doesn’t require any modification of the switch itself. It’s a reddit thread and imgur post, but the idea is just so good we can overlook the documentation on this one.

The key development behind this type of sensor is realizing that nearly every mechanical keyswitch (Cherry MX, Kalth, Gateron) has a spring in the bottom. A spring is just a coil of wire, and an inductor is just a coil of wire, too. By putting a spiral trace on the PCB of a mechanical keyboard underneath the keyswitch, you can sense the inductance of this spring. This does require a little bit of additional hardware, in this case an LDC1614 inductance to digital converter, but this is an I2C-readable part that can, theoretically, be integrated rather easily with any mechanical keyboard PCB and firmware.

The downside to using the LDC1614 is that sampling is somewhat time-limited, with four channels or individual keys being polled at 500 Hz. This isn’t a problem if the use-case is adding analog to your WASD keys, but it may become a problem for an entire keyboard. Additionally, the LDC1614 is a slightly expensive part, at about $2 USD in quantity 1000. A fully analog keyboard using this technique is going to be pricey.

Right now, the proof-of-concept for this analog mechanical keyswitch is just a 0.1 mm flexible PCB that is shoehorned inbetween a Cherry MX red and a (normal) mechanical keyboard PCB. The next step in the development will be a 2×4 keypad with analog sensors, and opening up the hardware and firmware examples up under a GPL license.

Giant Connect Four Pits You Against the Computer

พุธ, 09/26/2018 - 15:02

You can build a Connect Four solver in software, but it won’t be all that much fun. Now apply that same automation to a 15-foot-tall plywood version of the classic board game and you’ve just created a smile-making-machine for everyone within eyesight. Behold the Mono-Purpose Automated Robot Versed In Connnect4 (Marvin) which Ben and Jonathan dreamed up on their way home from Maker Faire last year, and made into their exhibit this year.

On the physical side of things they got really creative in lifting the discs and sorting them into the column chosen by the software brain of the game. A chain travels along one side with fingers every few feet. The fingers travel along the channel, lifting the discs. Those fingers are a couple of bolts, with some metal filler, all epoxied into one solid unit.

At the top of the disc elevator, and at the top position of each column in the gaming board, there are IR reflectance sensors which send feedback to the Arduino that drives the hardware. This proved a major issue during setup the day before the Faire. The reflectance sensors are just blasting out IR and not using a carrier signal. In direct sunlight, the detector was in a constant state of being tripped. After some trial and error, the logic for the sensors was flipped to detect the absence of sunlight by placing black plastic behind that top row of the board and putting duct tape over the IR emittors.

There’s a router and laptop rolled into the system. The Arduino makes an HTTP request to software on the laptop. In addition to determining where the next move should be made, the laptop is connected to a large screen which shows the current state of the gaming board. This is a head-to-head, human versus machine game. The human player drops their discs from the top of the board using a paint roller that hooks into a hole at the center of the disc. This way the player’s disc passes by the sensors, triggering the machine’s next move.

It’s a clever build and due to the sheer size it’s pretty awesome they were able to get it to the Faire from Philadelphia. Don’t miss the video after the break that shows off the fun and excitement of this gaming giant.

A Nibble And A Half Of Wooden Bits

พุธ, 09/26/2018 - 12:00

If you are familiar with binary, what would you need to teach someone who only knows decimal? If you do not know how to count in binary, let us know if the video below the break helps you understand how the base-2 number system works. If learning or counting binary is not what you are interested in, maybe you can appreciate the mechanics involved with making a counter that cycles through all the ones and zeros (links to the video shown below). The mechanism is simple enough. A lever at the corner of each “1” panel is attached off-center, so it hangs when it is upside-down, then falls to the side when it is upright, so it can swivel the adjacent panel.

Perhaps this is a desktop bauble to show off your adeptness at carpentry, or skills with a laser cutter, or 3D printer. No matter what it is made out of, it will not help you get any work done unless you are a teacher who wants to demonstrate the discrete nature of binary. If wood and bits are up your alley, we have a gorgeous binary driftwood clock to feast your eyes on. Meanwhile if analog methods of working digital numbers suit you, we have binary math performed with paper models.