Learn FPGA With This Persistence Of Vision Hack

August 31, 2018 by 11 Comments

Everybody wants to give FPGA development a try and here’s a great way to get into it. You can build your own Persistence of Vision display using a $30 dev board. It’s a fun project, and you’ll learn quite a bit about designing for an FPGA, as well as using the Quartus design software.

The inspiration for this article comes from [vpecanins] who did an example project where you wave the board back and forth and a message appears in mid air. This uses the MAX1000, a pretty powerful yet odd FPGA board for about $30. It contains an Intel MAX10 (when did Intel start making FPGAs? Remember, Intel bought Alterra back in 2015). I find the board odd because it also holds an accelerometer that you can talk to using SPI. That’s a little strange for a generic FPGA board, but paired with eight on-board LEDs it’s perfect for this demo.

Since I didn’t find any written documentation for this example, I thought we’d help out and take you on a step-by-step tour of the project. What’s more, in a future installment, I’ll show you how to make some significant changes to the tutorial that will make it even more practical as a base for other projects.

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New Mooltipass Begins Development With Call For Collaborators

August 31, 2018 by 14 Comments

One of the most interesting aspects of our modern world is the ability to work collaboratively despite the challenges of geography and time zones. Distributed engineering is a trend which we’ve watched pick up steam over the years. One such example is the Mooltipass offline password keeper which was built by a distributed engineering team from all over the world. The project is back, and this time the goal is to add BLE to the mini version of the hardware. The call for collaborators was just posted on the project page so head over and check out how the collaboration works.

The key to the hardware is the use of a smartcard with proven encryption to store your passwords. Mooltipass is a secure interface between this card and a computer via USB. The new version will be a challenge as it introduces BLE for connectivity with smart phones. To help mitigate security risks, a second microcontroller is added to the existing design to act as a gatekeeper between the secure hardware and the BLE connection.

Mathieu Stephan is the driving force behind the Mooltipass project, which was one of the first projects on Hackaday.io and has been wildly successful in crowd funding and on Tindie. Mathieu and five other team members already have a proof of concept for the hardware. However, more collaborators are needed to help see all aspects of the project — hardware, firmware, and software — through to the end. This is a product, and in addition to building something awesome, the goal is to turn a profit.

How do you reconcile work on an Open Source project with a share of the spoils? Their plan is to log hours spent bringing the new Mooltipass to life and share the revenue using a site like colony.io. This is a tool built on the Ethereum blockchain to track contributions to open projects, assigning tokens that equate to value in the project. It’s an interesting approach and we’re excited to see how it takes shape.

You can catch up on the last few years of the Mooltipass adventure my checking out Mathieu’s talk during the 2017 Hackaday Superconference. If this article has you as excited about distributed engineer as we are, you need to check out the crew that’s building this year’s Open Hardware Summit badge!

Make Your Python Prettier With Decorators

August 31, 2018 by 23 Comments

Many Pythonistas are familiar with using decorators, but far fewer understand what’s happening under the hood and can write their own. It takes a little effort to learn their subtleties but, once grasped, they’re a great tool for writing concise, elegant Python.

This post will briefly introduce the concept, start with a basic decorator implementation, then walk through a few more involved examples one by one.

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Single-Rotor Drone: A Thrust-Vectoring Monocopter

August 31, 2018 by 54 Comments

We’re not entirely sure what to call this one. It’s got the usual trappings of a drone, but with only a single rotor it clearly can’t be called by any of the standard multicopter names. Helicopter? Close, but not quite, since the rotor blades are fixed-pitch. We’ll just go with “monocopter” for now and sort out the details later for this ducted-fan, thrust-vectored UAV.

Whatever we choose to call it — builder [tesla500] dubbed it the simultaneously optimistic and fatalistic “Ikarus” — it’s really unique. The monocopter is built around a 90-mm electric ducted fan mounted vertically on a 3D-printed shroud. The shroud serves as a mounting point for the landing legs and for four servos that swivel vanes within the rotor wash. The vanes deflect the airstream and provide the thrust vectoring that gives this little machine its control.

Coming to the correct control method was not easy, though. Thanks mainly to the strong gyroscopic force exerted by the rotor, [tesla500] had a hard time getting the flight controller to cooperate. He built a gimballed test stand to work the problem through, and eventually rewrote LibrePilot to deal with the unique forces on the craft and tuned the PID loops accordingly. Check out the results in the video below.

Some attempts to reduce the number of rotors work better than others, of course, but this worked out great, and we’re looking forward to the promised improvements to come.

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Science Shows Green Lasers Might Be More Than You Bargained For

August 31, 2018 by 54 Comments

This may come as a shock, but some of those hot screaming deals on China-sourced gadgets and goodies are not all they appear. After you plunk down your pittance and wait a few weeks for the package to arrive, you just might find that you didn’t get exactly what you thought you ordered. Or worse, you may get a product with unwanted bugs features, like some green lasers that also emit strongly in the infrared wavelengths.

Sure, getting a free death ray in addition to your green laser sounds like a bargain, but as [Brainiac75] points out, it actually represents a dangerous situation. He knows whereof he speaks, having done a thorough exploration of a wide range of cheap (and not so cheap) lasers in the video below. He explains that the paradox of an ostensibly monochromatic source emitting two distinct wavelengths comes from the IR laser at the heart of the diode-pumped solid state (DPSS) laser inside the pointer. The process is only about 48% efficient, meaning that IR leaks out along with the green light. The better quality DPSS laser pointers include a quality IR filter to remove it; cheaper ones often fail to include this essential safety feature. What wavelengths you’re working with are critical to protecting your eyes; indeed, the first viewer comment in the video is from someone who seared his retina with a cheap green laser while wearing goggles only meant to block the higher frequency light.

It’s a sobering lesson, but an apt one given the ubiquity of green lasers these days. Be safe out there; educate yourself on how lasers work and take a look at our guide to laser safety. Continue reading “Science Shows Green Lasers Might Be More Than You Bargained For” →

Laser Arm Cannon Scares More Than Metroids

August 30, 2018 by 5 Comments

There’s an interesting side effect of creating a popular piece of science fiction: if you wait long enough, say 30 or 40 years, there’s a good chance that somebody will manage to knock that pesky “fiction” bit off the end. That’s how we got flip phones that looked like the communicators from Star Trek, and rockets that come in for a landing on a tail of flame. Admittedly it’s a trick that doesn’t always work, but we’re not in the business of betting against sufficiently obsessed nerds either.

Coming in right on schedule 32 years after the release of Metroid on the Nintendo Entertainment System, we now have a functional laser arm cannon as used by the game’s protagonist Samus Aran, courtesy of [Hyper_Ion]. It’s not quite as capable as its video game counterpart, but if your particular corner of the solar system is under assault from black balloons you should be in good shape. Incidentally no word yet on a DIY Power Suit that folds the wearer up into a tiny ball, but no rush on that one.

Modeled after the version of the weapon Samus carried in 2002’s iconic Metroid Prime, [Hyper_Ion] 3D printed the cannon in a number of pieces that screw together in order to achieve the impressive final dimensions. He printed it at 0.3 mm layers to speed up the process, but as you can probably imagine, printing life-size designs like this is not for the faint of heart or short of time. While the use of printed threads does make the design a bit more complex, the fact that the cannon isn’t glued together and can be broken down for maintenance or storage is a huge advantage.

Ever popular NeoPixel strips give the cannon a bit of flash, and a speaker driven by a 2N2222 transistor on an Arduino Nano’s digital pin allows for some rudimentary sound effects with nothing more than a PWM signal. In the video after the break you can see how the lights and sounds serve as a warning system for the laser itself, as the cannon can be seen “charging up” for a few seconds before emitting a beam.

Of course, this is the part of the project that might have some readers recoiling in horror. To provide some real-world punch, [Hyper_Ion] has equipped his arm cannon with a 2.5W 450nm laser module intended for desktop engraving machines. To say this thing is dangerous is probably an understatement, so we wouldn’t blame you if you decided to leave the laser module off your own version. But it certainly looks cool, and as long as you’ve got some proper eye protection there’s (probably) more dangerous things you can do in the privacy of your own home.

Shame this kind of technology wasn’t really practical back when [Ryan Fitzpatrick] made this fantastic Power Suit helmet for a Metroid fan production.

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The Boldport Cordwood And Cuttlefish, Together As A Guitar Tuner

August 30, 2018 by 1 Comment

As regular readers will know, here at Hackaday we are great enthusiasts for the PCB as an art form. On a special level of their own in that arena are the Boldport kits from [Saar Drimer], superlative objets d’art that are beautifully presented and a joy to build.

The trouble some people find with some of their Boldport kits though is that they are just too good. What can you do with them, when getting too busy with hacking them would despoil their beauty? [Paul Gallagher] has the answer in one case, he’s used not one kit but two of them as for a guitar tuner project.

At its heart is a Boldport Cuttlefish ATmega328 development board, and for its display it uses a Cordwood Puzzle as an LED array. All the details are available on a GitHub page, and it’s a modified version of an Arduino guitar tuner he found on Instructables. In particular he’s using a different pre-amp for an electret microphone, and a low-pass filter with a 723Hz cut-off to reduce harmonic content that was confusing the Arduino’s algorithm.

The result is a simple-to-use device with an LED for each string of his guitar, which you can see in the very short YouTube clip below. It joins many other tuners we’ve featured over the years, of which just one is this ATmega168-powered project with MIDI-out.

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