Automating RC Motor Efficiency Testing

Small brushless motors and LiPo batteries are one of the most impressive bits of technology popularized in recent years. Just a few years ago, RC aircraft were powered by either anemic brushed motors or gas. Quadcopters were rare. Now, with brushless motors, flying has never been easier, building electric longboards is simple, and electric bicycles are common.

Of course, if you’re going to make anything fly with a brushless motor, you’ll probably want to know the efficiency of your motor and prop setup. That’s the idea behind [Michal]’s Automated RC Motor Efficiency Tester, his entry to the 2016 Hackaday Prize.

[Michal]’s project is not a dynamometer, the device you should use if you’re measuring the torque or power of a motor. That’s not really what you want if you’re testing brushless motors and prop configurations, anyway; similarly sized props can have very different thrust profiles. Instead of building a dyno for a brushless motor, [Michal] is simply testing the thrust of a motor and prop combination.

The device is very similar to a device sold at Hobby King, and includes a motor mount, microcontroller and display, and a force sensor to graph the thrust generated by a motor and prop. Data can be saved to an SD card, and the device can be connected to a computer for automatic generation of pretty graphs.

Brushless motors are finding a lot of uses in everything from RC planes and quadcopters, to robotics and personal transportation devices. You usually don’t get much of a data sheet with these motors, so any device that can test these motors will be very useful.

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Hackaday Links: April 3, 2016

April Fool’s Day was last Friday, and the Internet was garbage for a day. Our April Fool’s prank was amazing, and in a single day garnered more views than the Raspberry Pi 3 launch announcement from a month prior. There just might be a market here for Apple. Here’s a short roundup of some of the best electronics April Fool’s posts:

This, surprisingly, was not an April Fool’s post. [Dave Jones] has been looking to upgrade his workspace for a few years now. He’s finally found a place. It’s the old Altium office in Sydney. [Dave] worked at Altium before spinning up the EEVblog, so this really is his old stomping grounds. It’s 4000 square meters (43,000 square feet), and exactly 3950 square meters larger than his current lab. What is he going to do with all that space? He’s looking for suggestions, but I would suggest an awesome model train layout. A [Dave Haynie]-style tour would also be acceptable.

Yesterday was the unofficial geekhack / deskthority / r/mechanicalkeyboards SoCal Mechanical Keyboard meetup at Datamancer in Montclair, CA. I was there, got a Control key to replace the Caps Lock key on my Novatouch, and took a lot of pictures.

It’s a presidential election year in the US, and that means millions of people are going to make America great again by polluting their front yard with campaign signs. These campaign signs are usually made out of coroplast, a material that looks like corrugated cardboard, but is made out of dead dinosaurs instead of dead trees. Coroplast is a very interesting material, and [uminded] tipped us off to some guy that makes mini speedboats in this rather uncommon material.

There are some things you just shouldn’t do. Combining octocopters with chainsaws, for example. You shouldn’t do it, but someone will anyway, and YouTube exists. Here’s an octocopter with a chainsaw.

Foxconn is buying Sharp. Sharp has a rather large portfolio of LEDs and optoelectronics, but this deal is mostly for Sharp’s large contract manufacturing business.

OSH Park Reintroduces Pogs

Remember Pogs? They’re back, in OSH Park form!

Some of you might be too young to remember, but the 90s were weird. If you need an example of this, you need only look at pogs. This was a schoolyard game using small cardboard discs and metal or plastic ‘slammers’. To play, stack the cardboard pogs, throw a slammer at the stack, and collect all the pogs that land face up. Of course, each cardboard pog was printed with full-color glossy pop culture images and were as collectible as comic books and baseball cards. The Bart Simpson ‘Public Enemy #1’ pog is highly prized. You could trade a pack of dunkaroos for three holofoils. I’m still looking for Animaniacs #27; my set is otherwise complete.

OSH Park0x07For the past few years, OSH Park, purveyors of perfect purple PCBs, put purple stickers into purple padded envelopes in each order. These stickers weren’t really anything special – just a rectangle with one rounded off corner, a gear, and the OSH Park URL. A few months ago, [Laen] at OSH Park ditched these plain purple stickers for something that taps into the same sentiment as the Apollo 13 pogs distributed through Hardee’s kids meals that included a modular Saturn V-shaped pog case and an aluminum slammer embossed on the obverse side with the Apollo 13 mission patch.

OSH Park’s newest stickers are numbered, limited edition, and feature unique artwork for each sticker in the series. They’re also hexagons, allowing anyone to tessellate their love for OSH Park all across their laptop. These are the OSHexagons, OSH Park’s newest stickers. Right now, [Laen] is drawing up and releasing about one design per month, with seven stickers out so far. Holding fast to OSH Park’s ideal of open standards, the OSHexagons utilize the Open Sticker Standard (yes, there is a standard for everything), making these stickers a regular hexagon that can be inscribed in a circle two inches in diameter.

The rare 0x03 OSHexagon from @sync_channel
The rare 0x03 OSHexagon from @sync_channel

While most of these stickers have runs in the thousands, OSH Park pulled a page from the history of pog and introduced a very speciallimited edition OSHexagon. Only 500 of the beautiful purple and gold 0x03 stickers were produced, making these collectors items equal in stature to the famous zinc alloy Austin 3:16 pog slammer.

As far as marketing goes, giving away a sticker with every order is pretty standard. The Hackaday Store includes a die-cut Jolly Wrencher with every order, but we order thousands of these every few months for events and shows. OSHexagon 0x03’s limited production turns it into an object to be cherished – coveted, even – that is easily digested by the gaping maw of fringe electronics trade journals and blogs. It’s a tour de force of marketing not seen since the 90s.

What’s next for OSH Park? If we’re following 90s trends and fads, you would think Beanie Babies would be next. Luckily, they already have that covered.

Apple Introduces Their Answer To The Raspberry Pi

Today, Apple has announced their latest bit of hardware. Following in the tradition of the Raspberry Pi, BeagleBone, and the Intel Edison, Apple have released a single board computer meant for embedded and Internet of Things applications. It’s called the Apple Device, and is sure to be a game changer in the field of low-power, Internet-enabled computing.

First off, some specs. The Apple Device uses Apple’s own A8 chip, the same dual-core 64-bit CPU found in the iPhone 6. This CPU is clocked at 1.1 GHz, and comes equipped with 1GB of LPDDR3 RAM and 4GB of eMMC Flash. I/O includes a Mini DisplayPort capable of driving a 4k display, 802.11ac, Bluetooth, and USB. In a massive break from the Apple zeitgeist of the last decade or so, the Apple Device also includes a forty pin header for expansion, much like the Raspberry Pi, BeagleBone, and Edison.

Although Apple’s first foray into the embedded computing market is a shocker, in retrospect it should come as no surprise; the introduction of HomeKit in iOS 9 laid the groundwork for an Internet of Apple Devices, embedded into toasters, refrigerators, smart homes, and cars. The Apple Device lives up to all these expectations, but what is the hands-on experience like?

See our review of the Apple Device after the break.

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Hackaday Teams With Vintage Computer Festival For Retro Hackathon

For the last few years, we’ve been going to the Vintage Computer Festival East in New Jersey. This is one of the best cons we go to every year; there are dozens of interesting exhibitors, awesome talks, a great venue, and a small consignment area filled with the weirdest stuff you can imagine. This year proves to be no different, and we’ll be there cataloging the weirdness and spectacular hacks of computer systems old enough to vote, plus something new.

Hackaday’s 8-bit game programming contest is happening for the first time at VCF East, April 15-17 in Wall, New Jersey. Competitors are given two and a half hours and an old 8-bit system (Apple II, C64, Atari 800, etc.). The goal is to create a game using only what is currently in memory, be that in the ROM or between the ears. There are two sessions on the Friday of the event, starting at 10am and 2:30pm.

You can call the 8-bit game programming contest a hackathon. That’s basically what it is; getting a small team together to whip up an application quickly with a number of constraints. The term ‘hackathon’ has been bastardized as of late, with companies requiring the use of a particular API or other nonsense. The 8-bit programming contest doesn’t have these limitations. All you need to do is create the coolest game in two and a half hours, and get the most applause from the audience. The best game wins a prize.

Of course, we’re not going to VCF East just to promote a retro hackathon. We’re only obliged to mention that first because we’re sponsoring it. VCF East is a fantastic event, with more retro goodies to satiate even the most curmudgeonly retro aficionado. The show is enormous with keynotes from [John Blankenbaker], inventor of the Kenbak-1 personal computer and [Stewart Cheifet], host of Computer Chronicles. Dr. Dr. Ted Nelson, author of Computer Lib and creator of Xanadu, the underlying software for computers that won’t be built for 100 years, will also be there. The weekend is, as always, packed with great exhibits of ancient tech, classes, and workshops.

Each Vintage Computer Festival is different, but if you’d like a sample of what it’s all about, check out these posts:

Apart from an announcement for the festival in New Jersey, there are a lot of changes in the organization of the various vintage computer festivals held around the country. The Vintage Computer Festival East was formerly organized by MARCH, the Mid-Atlantic Retro Computing Hobbyists. Late last year, MARCH was dissolved, and reformed as a 501(c)3 called the Vintage Computer Federation. The VCF (see what they did there?) also has the rights to hold VCF West, which last happened in 2007. The VCF Midwest, Southwest, Europe, and UK will remain independent.

If it isn’t already extremely obvious, this is one of the top-tier events we go to every year. No, it’s not DEF CON, it’s not HOPE, and it’s certainly not a big con. It’s just a bunch of nerds nerding out, which is the critical ingredient for the best events we attend all year.

The ATtiny MIDI Plug Synth

MIDI was created over thirty years ago to connect electronic instruments, synths, sequencers, and computers together. Of course, this means MIDI was meant to be used with computers that are now thirty years old, and now even the tiniest microcontrollers have enough processing power to take a MIDI signal and create digital audio. [mitxela]’s polyphonic synth for the ATtiny 2313 does just that, using only two kilobytes of Flash and fitting inside a MIDI jack.

Putting a MIDI synth into a MIDI plug is something we’ve seen a few times before. In fact, [mitxela] did the same thing a few months ago with an ATtiny85, and [Jan Ostman]’s DSP-G1 does the same thing with a tiny ARM chip. Building one of these with an ATtiny2313 is really pushing the envelope, though. With only 2 kB of Flash memory and 128 bytes of RAM, there’s not a lot of space in this chip. Making a polyphonic synth plug is even harder.

The circuit for [mitxela]’s chip is extremely simple, with power and MIDI data provided by a MIDI keyboard, a 20 MHz crystal, and audio output provided eight digital pins summed with a bunch of resistors. Yes, this is only a square wave synth, and the polyphony is limited to eight channels. It works, as the video below spells out.

Is it a good synth? No, not really. By [mitxela]’s own assertion, it’s not a practical solution to anything, the dead bug construction takes an hour to put together, and the synth itself is limited to square waves with some ugly quantization, at that. It is a neat exercise in developing unique audio devices and especially hackey, making it a very cool build. And it doesn’t sound half bad.

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Windows And Ubuntu: “Cygwin Can Suck It”

For the last ten years or so, computing has been divided into two camps: Windows, and everything else with a *nix suffix. Want a computing paradigm where everything is a file? That’s Linux. Want easy shell scripting that makes the command line easy? Linux. Want a baroque registry with random percent signs and dollar symbols? That would be Windows. Want to run the most professional productivity apps for design and engineering? Sadly, that’s Windows as well.

*nix runs nearly the entire Internet, the top 500 supercomputers in the world, and is the build environment for every non-Windows developer. Yet Windows is the most popular operating system. The divide between Windows and *nix isn’t so much a rivalry, as much as people who still spell Microsoft with a dollar sign would tell you. It’s just the way personal computing evolved by way of legacy apps and IT directors.

Now, this great divide in the world of computing is slowly closing. At Microsoft’s Build 2016 developer’s conference, Microsoft and Canonical, Ubuntu’s parent company, announced a partnership that will allow Ubuntu to run using native Windows libraries.

In short, this announcement means bash and the Linux command line is coming to Windows 10. The command line is great, but userland is where it’s at, and here this partnership really shines. Unlike Cygwin, the current way to get *nix stuff running in a Windows environment, Windows’ bash will allow unmodified Linux programs to run unmodified on Windows 10.

It is not an understatement to say this is the most important development in operating systems in the last 10 years. For the last decade, every developer who is not purely a Windows developer has picked up a MacBook for the sole reason of having BSD under the hood. If you’re looking for a reason Apple is popular with devs, it’s *nix under the hood. This announcement changes all of that.