Is It A Stepper? Or Is It A Servo?

Almost everyone who is involved with 3D printing thinks to themselves at some point, “this could all be done using a closed-loop system and DC motors”. Or at least everyone we know. There’s even one commercial printer out there that uses servo control, but because of this it’s not compatible with the rest of the (stepper-motor driven) DIY ecosystem.

[LoboCNC] wanted to change this, and he’s in a unique position to do so, having previously built up a business selling PIC-based servo controllers. His “servololu” is essentially a microcontroller and DC motor driver, with an input for a quadrature encoder for feedback. The micro takes standard step/direction input like you would use to drive a stepper motor, and then servos the attached DC motor to the right position. It even signals when it has an error.

The unfortunate side effect of [LoboCNC]’s old day job means that he can’t release the code that’s running his demo, but he says he’s working on a version of the firmware to open-source. Have a look at a demo video (below) of his modified servo printer that’s being driven by a standard stepper motor controller. It is certainly accurate!

If you want to get up to speed on all of this stepper vs. servo stuff, this video tutorial by [Homofaciens] is very much worth your while. In fact, it’s implementing a (non-PID, primitive) version of exactly what [LoboCNC] is aiming for. Which is not to take away from [LoboCNC]’s idea: shoehorning servo control into the existing form-factor of a stepper motor driver is a great idea, because it allows quick experimentation with a new motor drive mode. We can’t wait to see the software.

Anyone else taken a similar approach to closed-loop control on their 3D printers? We gave up ages ago, deciding that steppers were “good enough” when compared to the hassle of a complete redesign, so we’d love it if the “servololu” proved us wrong.

Thanks [Matt] for the tip!

Filed under: 3d Printer hacks

From zero to 100mph in 1.2 seconds, the SuperDraco thruster delivers

In this conceptual image, eight SuperDraco thrusters fire as a Dragon spacecraft enters the Martian atmosphere at supersonic speeds. (credit: SpaceX)

This week SpaceX announced plans to land a Dragon spacecraft on Mars by 2018. This would be a monumental achievement for NASA or any other national space agency, let alone a single company, considering the 6,000kg Dragon is nearly an order of magnitude more massive than anything previously landed on the red planet.

With the long-term goal of Mars colonization squarely in its crosshair, SpaceX has been testing key technologies needed to land on Mars for years. One of them is supersonic retro-propulsion, which Ars revealed has been tested on upgraded Falcon 9 rockets since September 2013. Supersonic retro-propulsion proved a resounding success.

But the Falcon 9 and its Merlin engines won't be going to Mars. SpaceX will use a different type of propulsion, the SuperDraco thruster, to propulsively land on the red planet. Here's how the landing will work: as the Dragon (dubbed Red Dragon) begins its descent to Mars at supersonic speeds, the spacecraft will fire eight of these thrusters into this onrushing atmosphere.

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Hacklet 105 – More Mind and Brain Hacks

A mind is a terrible thing to waste – but an awesome thing to hack. We last visited brain hacks back in July of 2015. Things happen fast on Hackaday.io. Miss a couple of days, and you’ll miss a bunch of great new projects, including some awesome new biotech hacks. This week, we’re checking out some of the best new mind and brain hacks on Hackaday.io

We start with [Daniel Felipe Valencia V] and Brainmotic. Brainmotic is [Daniel’s] entry in the 2016 Hackaday Prize. Smart homes and the Internet of Things are huge buzzwords these days. [Daniel’s] project aims to meld this technology with electroencephalogram (EEG). Your mind will be able to control your home. This would be great for anyone, but it’s especially important for the handicapped. Brainmotic’s interface is using the open hardware OpenBCI as the brain interface. [Daniel’s] software and hardware will create a bridge between this interface and the user’s home.

 

Next we have [Angeliki Beyko] with Serial / Wireless Brainwave Biofeedback. EEG used to be very expensive to implement. Things have gotten cheap enough that we now have brain controlled toys on the market. [Angeliki] is hacking these toys into useful biofeedback tools. These tools can be used to visualize, and even control the user’s state of mind. [Angeliki’s] weapon of choice is the MindFlex series of toys. With the help of a PunchThrouch LightBlue Bean she was able to get the EEG headsets talking on Bluetooth. A bit of fancy software on the PC side allows the brainwave signals relieved by the MindFlex to be interpreted as simple graphs. [Angeliki] even went on to create a Mind-Controlled Robotic Xylophone based on this project.

Next is [Stuart Longland] who hopes to protect brains with Improved Helmets. Traumatic Brain Injury (TBI) is in the spotlight of medical technology these days. As bad as it may be, TBI is just one of several types of head and neck injuries one may sustain when in a bicycle or motorcycle accident. Technology exists to reduce injury, and is included with some new helmets. Many of these technologies, such as MIPS, are patented. [Stuart] is working to create a more accurate model of the head within the helmet, and the brain within the skull. From this data he intends to create a license free protection system which can be used with new helmets as well as retrofitted to existing hardware.

Finally we have [Tom Meehan], whose entry in the 2016 Hackaday Prize is Train Your Brain with Neurofeedback. [Tom] is hoping to improve quality of life for people suffering from Epilepsy, Autism, ADHD, and other conditions with the use of neurofeedback. Like [Angeliki ] up above, [Tom] is hacking hardware from NeuroSky. In this case it’s the MindWave headset. [Tom’s] current goal is to pull data from the TAGM1 board inside the MindWave. Once he obtains EEG data, a Java application running on the PC side will allow him to display users EEG information. This is a brand new project with updates coming quickly – so it’s definitely one to watch!

If you want more mind hacking goodness, check out our freshly updated brain hacking project list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Filed under: Hackaday Columns

The leap second: Because our clocks are more accurate than the Earth

(credit: Toni Verdú Carbó)

We've recently been treated to that extra day in February that reminds us that 2016 is a leap year. Introduced by Julius Caesar, the leap day is necessary because the orbital year is not exactly equal to the 365 days of our calendar year. Without the adjustment, this year’s spring-like Christmas would eventually become routine even without climate change. After a few more generations, the snows of July would give way again to sweltering afternoons. Given enough time, the seasons would march across the calendar.

In order for the months to retain their traditional characters, the leap day is inserted every four years (with some exceptions). It keeps the calendar in sync with our expectations for the seasons.

But throwing an occasional day at the problem isn't enough. Just as a watch requires periodic adjustments to keep it in agreement with the real time, we need to make occasional tweaks to our global watch. But what is this global watch, and what is the “real” time that it needs to agree with?

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Weekend Watch: Building Comically Giant Swords with Michaelcthulhu

Mike Craughwell (aka Michaelcthulhu) makes awesome giant swords for a living. If you've ever wanted a ridiculous large sword, he's your man.

Read more on MAKE

The post Weekend Watch: Building Comically Giant Swords with Michaelcthulhu appeared first on Make: DIY Projects and Ideas for Makers.

Megaprocessor is a Macro Microprocessor

Windows 95 On An Apple Watch

What happens if the slick user interface and tight iOS integration of your Apple Watch leave you wanting more? A real operating system, from the days when men were men and computers were big grey boxes!

[Nick Lee] solved this unexpected problem with his Watch by getting a working copy of Windows 95 to run on it. On paper it shouldn’t be at all difficult, with a 520 MHz ARM, 512 MB of RAM, and 8GB of storage you might think that it would eclipse the quick 486s and low-end Pentiums we ran ’95 on back in the day with ease. But of course, the ability to run aged Redmond operating systems on a Watch was probably not at the top of the Apple dev team’s feature list, so [Nick] had to jump through quite a few hoops to achieve it.

As you might expect, the ’95 installation isn’t running directly on the Watch. In the absence of an x86 processor his complex dev process involved getting the Bochs x86 emulator to compile for the Watch, and then giving that a ’95 image to boot. The result is comically slow, with a 1-hour boot time and a little motor attached to the Watch to vibrate it and stop it going to sleep. It’s not in any way a useful exercise, after all who’d really want to use ’95 on a Watch? Internet Explorer 3 and The Microsoft Network, how handy! But it’s one of those “because you can” exercises, and we applaud [Nick] for making it happen. If you want to give it a try, his Bochs-forWatchOS code is on Github.

The video below the break shows the process of booting the ’95 Watch, opening the Start Menu, and running one of the card games. One can almost feel the lengthening shadows outside as it goes.

There seems to be a curious attraction in our community to getting Windows 95 to run on unexpected devices. We remember seeing people doing it on the then-just-launched Raspberry Pi back in 2012, and here at Hackaday we’ve featured it running on Nokia N-series Symbian phones and a GP2X games console. Some people will do anything to hear the Windows Sound.

Filed under: clock hacks, computer hacks, wearable hacks

Bring an “escape room” into your living room… for $22

(credit: Thinkfun)

Welcome to Ars Cardboard, our weekend look at tabletop games! Check out our complete board gaming coverage right here—and let us know what you think.

Who knew being locked in a room would become so popular?

"Escape rooms" are so hot that even my sleepy Chicago suburb has one. Just plop down 30 bucks, and you too can be locked for an hour inside a foam-stone medieval "dungeon" located right next to a butcher shop. Each group of ten guests has to find a way out of the room before the hour expires. This generally involves solving cooperative puzzles, parsing clues, figuring out a mystery, and popping open a giant lock.

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Knowledge of climate change basics doesn’t make people care

(credit: UN Photo/Eskinder Debebe)

Improving the public's understanding of anthropogenic climate change is vital to cultivating the political will to do something about it. However, a lot of research has shown that simply improving people’s understanding won’t necessarily do much to change their stance. This is because people’s opinions on many topics rest largely on their political affiliation, rather than how well they understand the science.

That leaves us with a thorny state of affairs. If improving science education isn’t going to shift public opinion, what can? A recent paper in Nature Climate Change suggests that education might not be as hopeless a cause as previously thought—but the work has some important limitations that may not give us much cause for optimism.

A problem with previous research on the topic is that “knowledge about climate change” was treated as a monolith, the authors of the new paper argue. Past studies didn't take into account that there are different kinds of knowledge about climate change. While knowledge in one area might be influenced by ideology, knowledge in other areas might not be.

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Don’t Tempt the Demo Gods

Including a live technical demonstration as part of a presentation is a lot like walking a tightrope without a net. Which isn’t to say that we don’t do it — we just keep our fingers crossed and bring our lucky horseshoe. The demo gods have smote [Quinn] a mighty blow, in front of a class at Stanford, no less.

[Quinn]’s scratch-built computer, Veronica, failed to boot in front of a hall of eager students. When the pressure was off, in the comfort of her own lab, [Quinn] got to debugging. You should read her blog post if you’re at all interested in retrocomputing or troubleshooting of low-level hardware bugs. But if you just can’t spare the five minutes for a pleasant read, here’s a spoiler: watch out for flaky card-edge connectors. All’s well that ends well, with a game of pong.

We’ve been following Veronica from her very first clock cycles, so we’re happy to see her back on her feet again. Good job, [Quinn]!

Filed under: repair hacks

Line Following Robot Trains Runners

 

Can your line following robot move faster than [Usain Bolt] who has been described as “The World’s Fastest Timed Human”? Puma, the athletic footwear, apparel and accessories company, created such a robot to help train their company sponsored athletes.

The shoebox-sized robot exceeds [Bolt]’s top speed of 44-km/hour. At that speed, following a line gets tricky. It took the development team 8 prototypes to attain that capability. Inside the BeatBot an Arduino reads 9 infrared sensors for line detection at 100 samples a second. A digital servo controls the Ackerman steering mechanism to follow the line on the track or floor. Wheel encoders provide the data for speed and distance measurement.

The user can set the distance of the run and the time to beat. Run pacing can also be adjusted. LEDs on the robot provide the starting ‘gun’ and help the runner see the BeatBot using peripheral vision. Two GoPro cameras, front and rear, provide a visual record of the run.

Puma believes that actually running against a competitor, even a robot, improves performance more than just running against the clock. They’re betting a grown-up line follower will help Olympic class athletes improve their performance.

Filed under: robots hacks

1btn – an Open Source Dash

The availability of cheap radios, omni-present WiFi and powerful web services means the IoT wave is here to stay. Amazon got into the act with its “do only one thing” Dash button. But a more interesting solution would be an IoT “do it all” button.

[Anand] has been working on his 1btn Open Source WiFi connected IoT button for a while. It connects to the Internet over WiFi to trigger whatever action you have assigned to it using a simple, online interface. It’s reconfigurable and open source. Which means it can be used in pretty imaginative ways, and if needed, can be re-flashed with your own custom firmware should you decide to really get under its hood.

The 1btn’s ESP8266 module is usually in sleep mode, waking up when the button is pressed, making the connection, performing the task and then going back to sleep once confirmation is received. A Red/Green LED indicates if the action was successful or not. You can set it up to send e-mails, messages, tweets or perform actions via a custom script, API or the IFTTT – maker channel. To make it hacker friendly, all of the ESP8266 GPIO pins are accessible via headers. This makes it convenient to add external sensors, for example. There’s also a (unpopulated) QFN footprint to allow adding an ATmega device (168P/328P) whose GPIO pins are also accessible via headers. This opens up a large number of additional applications for the device such as home automation.

On the software side, the 1btn connects to a web console, where you can set up an account, configure the device, register its MAC ID, assign it an alias and set up its actions. All of the source files for the 1btn – firmware, enclosure, schematic, BOM, PCB layout and example use cases – are posted on his Github repository.

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Filed under: The Hackaday Prize, wireless hacks

Soda Fridge Hack to Fix a Lazy People Problem

ESP8266 or MKR1000?

If you are a regular Hackaday reader, you’ve probably seen plenty of ESP8266 projects. After all, the inexpensive device is a workhorse for putting a project on WiFi, and it works well. There is a processor onboard, but, most often, the onboard CPU runs a stock firmware that exposes an AT command set or Lua or even BASIC. That means most projects have a separate CPU and that CPU is often–surprise–an Arduino.

It isn’t a big leap of logic to imagine an Arduino with an integrated WiFi subsystem. That’s the idea behind the MKR1000. But the real question you have to ask is: is it better to use an integrated component or just put an Arduino and ESP8266 together?

[Andreas Spiess] not only asked the question, but he answered it in a YouTube video (see below). He examines several factors on the MKR1000, the Arduino Due and Uno, and several other common boards. The examination covers performance, features, and power consumption.

We’ve covered a slew of ESP8266 projects. We’ve also seen at least two MKR1000 projects, one for an automotive project and the other controls a shower.

Filed under: Arduino Hacks, wireless hacks

Drugs, wine, mushy poops explain gut microbe variation—but just a little

Homogenized fecal matter for transplantation (credit: Wikimedia)

Our guts are teeming with trillions of microbes. They fight, form alliances, gobble our food, spew chemicals, and hack our immune systems. These hidden happenings in our innards hold sway over our health. Yet the key microbial players and their affairs vary considerably from person-to-person. And, overall, these communities remain a mystery to scientists.

This week, three studies published in the journal Science offer new glimpses of what’s going on in the black box that is our guts. While they all provide insights into these complex communities, they also highlight just how much we still have to learn.

Two studies dug into people’s health and, literally, their poop looking why there is so much variation in gut microbiome. Factors the studies hoped might explain that variation include diet, medication, disease, and stool types—from hard lumps to mushy piles according to the Bristol stool scale. The studies looked at samples from 1,135 Dutch and 1,106 Belgian volunteers. Researchers found that such factors account for only 18.7 percent and 7.6 percent, respectively, of variation. What differences account for the rest are complete unknowns.

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John Romero Kickstarter put on “hold” until playable demo is complete

We'll have to wait until the demo's complete to see how these Blackroom weapons will work in John Romero's next video game. (credit: John Romero)

John Romero announced his return to video game development on Monday in the form of a Kickstarter project, but he and another ex-id Software veteran, Adrian Carmack, apparently agreed with Ars' initial assessment of their crowdfunding campaign. The duo has now put its money request on hold, declaring that they will return once they can put a playable demo into the hands of their fans.

"The team is at work on a demo which demonstrates the kind of gameplay, look, and innovative, cool features that make Blackroom truly unique," Romero announced in a "backer-only" update post. "Simply put, this will take more time than the Kickstarter has left, so we’ve decided to suspend the campaign and launch a new one when the gameplay demo is ready."

Blackroom's Monday announcement came with little more than big promises of a return to "classic" first-person shooter gameplay, a few snippets of concept art, and the confirmation of a single additional staffer in the form of a "metal composer." Instead of putting any money where his mouth is, Romero instead teased fans with a pair of remade levels (1, 2) from the original version of Doom—as in, downloadable WAD files you could inject into the original executable. Those throwback levels were admittedly very good, but they failed to illustrate new mechanics or systems to expect in a new game.

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