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Super Computing with Mini ITX Cluster

พฤ, 03/16/2017 - 22:31

[Colin Alston] was able to snag a handful of Mini ITX motherboards for cheap and built a mini super computer he calls TinyJaguar. Named partly after the AMD Sempron 2650 APU, the TinyJaguar boasts four, yes that’s four MSI AM1I Mini-ITX motherboards, each with 4GB of DDR memory.

A Raspberry Pi with custom software manages the cluster, and along with some TTL and relays, controls the power to the four nodes. The mini super computer resides in a custom acrylic case held together by an array of 3D printed parts and fasteners.There’s even a rack-like faceplate near the bottom to host the RPi, an Ethernet switch, an array of status LEDs, and the two buttons.

With 16 total cores of computing power (including GPU), the TinyJaguar is quite capable of doing some pretty cool stuff such as running Jupyter notebook with IPyParallel. [Colin] ran into some issues getting the GPU to behave with PyOpenCL. It took a bit of pain and time, but in the end he was able to get the GPUs up, and wrote a small message passing program to show two of the cores were up and working together.

Be sure to check out [Colin’s] super computer project page, specifically the ten project logs that walk through everything that went into this build. He also posted his code if you want to take a look under the hood.

Filed under: computer hacks, Raspberry Pi

Two Bits a Gander: Of Premature Babies, Incubators, and Coney Island Sideshows

พฤ, 03/16/2017 - 21:01

Newborn humans are both amazingly resilient and frighteningly fragile creatures. A child born with a 40 full weeks of gestation has pretty good odds of surviving the neonatal period these days, and even if he or she comes along a few weeks early, things usually go smoothly. But those babies that can’t wait to get out and meet the world can run into trouble, and the earlier they’re born, the greater the intervention needed to save them.

We’ve all seen pictures of remarkably tiny babies in incubators, seemingly dwarfed by the gloved hands of an anxious parent who just wants that first magical touch of their baby’s skin. As common as such an intervention is now and as technologically advanced as neonatology is, care for premature infants as a medical discipline has a long and interesting history of technical and social hacks that’s worth looking at.

There was a time when most infants were born at home, and childbirth was strictly woman’s work. Mother and midwife, and perhaps the future grandmother or aunt, were generally the only ones allowed in the birthing room. Doctors, uniformly male at the time, were not welcome and generally not needed.

Complications were common, of course, and the medical community gradually began to increase the doctor’s role in childbirth, particularly in unusual cases such as premature delivery. A Paris obstetrician, Stephane Tarnier, began to notice that premature infants, most of whom lack the insulating body fat of full-term babies and a fully developed thermoregulation system, need more than warmth to survive. He realized that infection was also a risk to the neonate with a still-developing immune system, and started using “incubator cribs” in the Paris Maternité in 1881. These incubators were inspired by poultry-egg incubators and were little more than wooden boxes with a glass lid. Warmed by water bottles, they required constant attention, but the combination of heat, humidity, and isolation, along with proper nutrition and round the clock care, reduced the infant mortality rate in the Maternité by 28% in three years.

Heretic 1909 Baby Incubator

Despite the advances made by the good Dr. Tarnier, he still faced an uphill battle bucking conventional medical wisdom at the time, which said that helping premature infants was a fool’s errand. Dr. Tarnier stuck to it, though, attracting students to his methods. He passed the torch to Dr. Pierre Budin upon his retirement, and by the last decade of the 1800s incubators were becoming more accepted, and the treatment of premature infants was becoming expected.

But there remained a problem: the round the clock care demanded by these tiny humans was expensive. On top of that, incubators were getting more sophisticated – gone were the days of hot water bottles; incubators were now thermostatically controlled and automatically ventilated — and therefore more expensive. Many parents lacked the means to care for a premature infant using the latest methods, with predictably tragic results.

As a way to fund neonatal care and bring it to parents of more modest means, Dr. Alexandre Lion, inventor of a new and sophisticated incubator, hit upon the idea of setting up a neonatal care ward in a street-level storefront in Paris. Passersby were enticed to enter for a fee and observe the very latest in neonatal care. These “incubator charities” were wildly successful, and they began to spring up throughout France. Eventually, Dr. Lion put together a Kinderbrutenstalt, or “child hatchery,” for the Berlin Exposition of 1896, which was a huge hit that raised a lot of money and educated the public about neonatal care.

Incubators Taken on World Tour

Enter one Martin Couney, an associate of Dr. Budin. Couney is a shadowy figure — he was born somewhere in Germany sometime in either 1860 or 1870, and he may or may not have actually been a medical doctor. Whatever his professional credentials, he was clearly a showman. He was tasked by Budin to take part in the Kinderbrutenstalt where he made contact with a London-based promoter to bring the show to England for the Victorian Exposition.

Dreamland 1907, one of the Coney Island amusement parks

Dr. Couney’s success in London, which came despite the fact that local doctors refused his request for preemies, forcing him to import a shipment of Parisian preemies for the occasion, led to appearances at multiple expositions across Europe over the next few years. Eventually he brought his incubator show to America for the Pan-American Exposition in Buffalo in 1901, again to rave reviews. The tiny baby business was booming, and as a consequence, a lot of preemies were being saved.

When Dr. Couney eventually decided to move to the United States permanently in 1903, and settled in the one place where a showman of his magnitude could — Coney Island, NY. There he set up a shop on the boardwalk, showing off his “All the World Loves a Baby” show every summer for the next 40 years. His show competed with dozens of others in the typical way; colorful signs, waifs distributing handbills in the crowds, and barkers entreating folks not to miss the show. One struggling actor who did time as a barker for Dr. Couney’s show was a young Archibald Leach, whom the world would later know as Cary Grant.

The End of an Odd Era

Couney always stated that he never took a dime from the parents to care for the babies. He took his show on the road frequently, culminating with a last hurrah at the 1939 World’s Fair in Flushing Meadows, New York. He closed down the Coney Island sideshow a few years later, since by then incubator care for preemies had become more or less mainstream. That means the last crop of Dr. Couney’s sideshow preemies is just hitting their mid-70s.

To our 21st century sensibilities, putting babies on display to raise money is perhaps a little unseemly. The early “incubator charities” seem a little more refined than a boardwalk sideshow for “two bits a gander,” but at the end of the day, Dr. Couney and his showman-physician predecessors did what they could to keep the babies alive and advance the technology to do so. Is it really that much different than any modern-day crowdfunding effort? And as for its unseemliness, is it any different than your reality-show Duggars or Honey Boo-Boos or OctoMoms? At least the sideshows ended up advancing the state of the art while coarsening the culture.

So spare a thought for Dr. Couney and the others the next time you see a preemie in an incubator, which might not be as advanced without their showmanship.

Filed under: Featured, History, Medical hacks

Robot Ants Wear Circuitry as Exoskeleton

พฤ, 03/16/2017 - 18:01

[FESTO] keeps coming up with new tricks that make us both envious and inspired. Take their bionicANTs for example. Watching a group of them cooperate to move objects around looks so real that you’re instantly reminded of the pests crawling across your floor, but looking at them up close they’re a treasure trove of ideas for your next robot project.

Ant exoskeleton as circuit board

The exoskeleton is 3D printed but they then use the outer surface of that exoskeleton as a circuit board for much of the circuitry. The wiring is “painted on” using a 3D MID (Molded Interconnect Device) process. While FESTO didn’t give specifics about their process, a little research shows that 3D MID involves the 3D printed object being made of a special non-conductive metal material, a laser then “drawing” the traces in the material, and then dipping the object in various baths to apply copper, nickel and gold layers. We mortal hackers may not have the equipment for doing this ourselves in our workshops but seeing the beautiful result should be inspiration enough to get creative with our copper tape on the outer surfaces of our 3D printed, CNC’d, or hand-carved parts.

We also like how they took a the mouse sensor from under a regular computer mouse and attached it to the ant’s underside, pointing down for precision dead reckoning. For the legs they used three piezo bending transducers. However, these give a deflection of only 1.5mm in both directions, not enough for walking. They increase this to over 10mm with the addition of a plastic hinge, another idea to keep in mind when building that next tiny robot. And there are more ideas to be taken advantage of in their ants, which you can see being built in the video below.

But this isn’t the only time FESTO’s creative ingenuity has been shown here on Hackaday. Check out their bionic kangaroo that actually hops around, their robotic bird that has to be the most life-like one we’ve see yet, or how about their flying manta ray blimp instead.

Filed under: robots hacks

Roam the Wastelands with this Fallout-Themed Mini Geiger Counter

พฤ, 03/16/2017 - 15:01

For anyone who has worked with radioactive materials, there’s something that’s oddly comforting about the random clicks of a Geiger counter. And those comforting clicks are exactly why we like this simple pocket Geiger counter.

Another good reason to like [Tim]’s build is the Fallout theme of the case. While not an item from the game, the aesthetic he went for with the 3D-printed case certainly matches the Fallout universe. The counter itself is based on the popular Russian SBT-11A G-M tubes that are floating around eBay these days. You might recall them from coverage of this minimalist Geiger counter, and if you were inspired to buy a few of the tubes, here’s your chance for a more polished build. The case is stuffed with a LiPo pack, HV supply, and a small audio amp to drive the speaker. The video below shows it clicking merrily from a calibration source.

We can see how this project could be easily expanded — a small display that can show the counts per minute would be a great addition. But there’s something about how pocketable this is, and just the clicking alone is enough for us.

Filed under: misc hacks, tool hacks

Scrap Wood and Metal Combined for DIY Mecanum Wheels

พฤ, 03/16/2017 - 12:00

Some scrap wood, a few pieces of sheet metal, a quartet of old gear motors, and a few basic hand tools. That’s all it takes to build an omni-bot with Mecanum wheels, if you’ve got a little know-how too.

For the uninitiated, Mecanum wheels can rotate in any direction thanks to a series of tapered rollers around the circumference that are canted 45° relative to the main axle.  [Navin Khambhala]’s approach to Mecanum wheel construction is decidedly low tech and very labor intensive, but results in working wheels and a pretty agile bot. The supports for the rollers are cut from sheet steel and bent manually to hold the wooden rollers, each cut with a hole saw and tapered to a barrel shape on a makeshift lathe. Each wheel is connected directly to a gear motor shaft, and everything is mounted to a sheet steel chassis. The controls are as rudimentary as the construction methods, but the video below shows what a Mecanum-wheeled bot can do.

There’s a lot of room here for improvement, but mainly in the manufacturing methods. The entire wheel could be 3D printed, for instance, or even laser cut from MDF with a few design changes. But [Navin] scores a win for making a working wheel and a working bot from almost nothing.

Thanks for the tips, [Karl Rosenqvist]!

Filed under: misc hacks, robots hacks

Strandbeest Not Fooling Anyone — We See Right Through It

พฤ, 03/16/2017 - 09:00

This Strandbeest is ready for the security line at a security-conscious high school. Like see-though backpacks, its clear polycarbonate parts let you see everything that goes into the quirky locomotion mechanism. Despite having multiple legs, if you analyze the movement of a Strandbeest it actually moves like a wheel.

For us, it’s the narrated fabrication video found below that makes this build really interesting. Hackaday alum [Jeremy Cook] has been building different versions of [Theo Jansen’s] Strandbeest for years now. Strandmaus was a small walker controlled by a tiny quadcopter, and MountainBeest was a huge (and heavy) undertaking. Both were made out of wood. This time around [Jeremy] ordered his polycarbonate parts already cut to match his design. But it’s hardly a walk on the beach to make his way to final assembly.

The holes to accept the hardware weren’t quite large enough and he had to ream them out to bring everything together. We enjoyed seeing him build a jig to hold the spacers for reaming. And his tip on using an offset roll pin to secure the drive gear to the motor shaft is something we’ll keep in mind.

In the end, things don’t go well. He had machined out a motor coupling and it ends up being too weak for the torque driving the legs. Having grown up watching [Norm Abram] build furniture (and houses) without a single blown cut or torn-out end grain this is a nice dose of reality. It’s not how perfect you can be with each step, it’s how able you are to foresee problems and correct them when encountered.

Filed under: robots hacks

Hardware Tribes Growing Up Around Artisanal Electronics

พฤ, 03/16/2017 - 06:00

Consumer electronics are design beasts that must serve many masters. There’s a price point for the product itself, a ceiling for the feature set (lest it not be ‘user friendly’), and to take the risk of actually manufacturing something there needs to be proof of the market. A lot of great things make it through this process, but some really unique and special gear goes completely around it.

So is the story of this AND!XOR hardware badge being built for DEF CON 25. This is not the official conference badge, but the latest in a growing trend of hardware/firmware engineers and hackers who design their own custom gear for the conference, trying to one-up not just the official badge, but the other hardware tribes doing the same. This unique hardware excitement is a big reason that Hackaday has developed electronic badges for our conferences.

The new badge is a mashup of Bender from Futurama and Raoul Duke from Fear and Loathing in Las Vegas, presents something of monstrosity to hang around your neck. That has certainly never stopped us from having one of these bouncing around our necks as we pound the cattle paths from talk to talk (and the DC23 vinyl record was way more unwieldy anyway).

Bender’s forehead display has now been upgraded from a diminutive OLED to a generous color LCD display. The 433 MHz which used the spring antenna on the previous badge has given way to a Bluetooth Low Energy. The BLE is built into the Rigado BMD-300 SOC that is now in conrol of the badge. We can’t wait to see the shenanigans unlocked with this new hardware — they’re already showing of crazy animations, retro gaming, and teasing a huge multiplayer game with all the badges. Finally, the “Secret Component” at the bottom of their components list delivers the je ne sais quoi to the whole project.

Fans of AND!XOR have already thrown their weight behind it. Unofficial badges have been unavailable to a wider group or only offered in flash-sales that pop up during the con. Last year the team was met with a huge mob throwing money at their supply of 175 badges. Now the AND!XOR team has grown to five people toiling away to make the design, the easter-egg laden firmware, and the manufacturing process better than the amazing work of last year. They just launched a crowd funding campaign on Tuesday and immediately blew past their goal about five times over.

We’re hoping to get our mitts on one of these ahead of DEF CON to give you an early look at what these hardware artists have accomplished. If you’re part of another hardware tribe building custom electronics for the love of it, we’d really like to hear from you. This goes for any conference — we know of at least one other in progress.

Filed under: cons, Crowd Funding

Starfish Cat, Bowling Ball Bot, and Stargate all Claim Prizes

พฤ, 03/16/2017 - 03:01

We saw a huge outpouring of builds for the the Hackaday Sci-Fi Contest and it’s now time to reveal the winners. With 84 great themed projects submitted, the judges had a tough task to pull out the most impressive both in terms of creativity and execution.

Here are our four winners. Two come from the Stargate universe. One is a cuddly yet horrifying character of unknown origin but unarguably Sci-Fi. The other is the best use of a bowling ball we’ve seen so far.

Grand Prize

The grand prize goes to [Jerome Kelty] with Animatronic Stargate Helmet. [Jerome] has built a replica prop that looks like it just came out of a Hollywood shop. It’s almost a shame that this helmet won’t be worn on film – though it certainly could be. If you remember the film and the television show, these helmets have quite a bit of articulation. The head can pan and tilt. The eyes glow, as well as have irises which expand and contract. The “wings” also open and close in a particular way.

[Jerome] built the mechanics for this helmet. He used radio control servos to move the head, with the help of some hardware from ServoCity. Most of the metalwork was built in his own shop. Everything is controlled from a standard R/C transmitter, much like the original show. [Jerome] is taking home a Rigol DS1054Z 4 Channel 50 MHz scope.

First Prize

First prize goes to [Christine] with
Starfish Cat: Your Lovecraftian Furby-like Friend. Starfish Cat is one of those odd projects that finds itself right on the edge of the uncanny valley. We are equal parts intrigued and creeped out by this… thing. The bottom is all starfish, with a rubber base poured into a 3D printed mold. The top though, is more cat-like, with soft fur and ears. 5 claws hide under the fur, ready to grab you.

Starfish Cat detects body heat with 5 bottom mounted PIR sensors. The sensors are read by the particle photon which acts as its brain. When heat is detected, Starfish Cat activates its claws, and also blows or sucks air through its… uh… mouth hole.  [Christine] is taking home a Monoprice Maker Select Mini 3D printer.

Click past the break to see the rest of the winners

Second Prize

Second Prize goes to [Jochen Alt] with Paul. Paul is a balancing robot. He rides on a ball by driving 3 omnidirectional wheels. You might think he was inspired by BB-8, but [Jochen] has been working on balancing robots for years now — even longer than BB-8 has been around.

Paul is powered by a pair of Atmel ATmega644 microcontrollers. One handles balance and motor drive. The other micro drives the speakers, LEDs, and takes commands from an XBee radio.

Did we mention that Paul recites somewhat depressing poetry while riding on his ball? He might be related to Marvin the paranoid android. [Jochen] is rolling away with a complete Blu-Ray box of Star Trek: The Next Generation.

Third Prize

In third place, we have [shlonkin] with Ma’Tok staff weapon from Stargate. Who knew we had so many Stargate fans among our readers?

[Shlonkin] didn’t have access to all the composites [Jerome] used, so he carved the staff entirely out of wood. A hidden trigger allows the Ma’Tok’s wielder to arm and fire the weapon. Sequenced LEDs take the place of the electrical discharges in the real thing. The Ma’Tok is controlled by an Adafruit Pro Trinket, which also drives a servo hidden in the head. The servo allows the Ma’Tok to “fire” a small projectile. The projectile was built from a tiny flashlight. It almost looks like a bolt of electricity when fired.

[Shlonkin] is taking home a Lego Millennium Falcon.

So that’s another contest all wrapped up. Congratulations to all the winners!  We’d like to thank everyone who entered, as well as the judges who toiled through the night to pick the best entries.

Filed under: contests

The BeagleBone Blue – Perfect For Robots

พฤ, 03/16/2017 - 01:30

There’s a new BeagleBone on the block, and it’s Blue. The BeagleBone Blue is built for robots, and it’s available right now.

If a cerulean BeagleBone sounds familiar, you’re not wrong. About a year ago, the BeagleBone Blue was introduced in partnership with UCSD. This board was meant for robotics, and had the peripherals to match. Support for battery charging was included, as well as motor drivers, sensor inputs, and wireless. If you want to put Linux on a moving thingy, there are worse choices.

The newly introduced BeagleBone Blue is more or less the same. A 9-axis IMU, barometer, motor driver, quad encoder sensor, servo driver, and a balancing LiPo charger are all included. The difference in this revision is the processor. That big square of epoxy in the middle of the board is the Octavo Systems OSD3358, better known as a BeagleBone on a chip. This is the first actual product we’ve seen using this neat chip, but assuredly not the last – a few people are working on stuffing this chip onto a board that fits in mini Altoids tins.

Filed under: hardware

Fire Hazard Testing

พฤ, 03/16/2017 - 00:01

How do you know that new appliance you bought won’t burn your house down? Take a look at any electrical appliance, and you’ll find it marked with at least one, and most often, several safety certification marks such as UL, DIN, VDE, CSA or BSI. Practically every electrical product that plugs into utility supply needs to go through a mandatory certification process to ensure it meets these conformity test requirements. Some examples include domestic and industrial electrical appliances, tools, electrical accessories, consumer electronics and medical electronics.

When you look through a typical safety test standard, you’ll notice it breaks down the various tests in two categories. “Type” tests are conducted on prototypes and samples of the final product or its individual parts and components, and are not generally repeated unless there are changes in design or materials. “Acceptance” tests are routine verification tests conducted on 100% of the products produced. For example, a typical Type test would be used to check the fire retardant properties of the plastics used in the manufacture of the product during development, while a Routine test would be carried out to check for high voltage breakdown or leakage and touch currents on the production line.

Nowadays, a majority of countries around the world adopt standards created by international organizations such as IEC, ISO, and ITU, then fine tune them to suit local requirements. The IEC works by distributing its work across almost 170 Technical Committees and Subcommittees which are entrusted with the job of creating and maintaining standards. One of these committees is “TC89 Fire hazard testing” whose job is to provide “Guidance and test methods for assessing fire hazards of electro-technical equipment, their parts (including components) and electrical insulating materials”. These tests are why we feel safe enough to plug something in and still sleep at night.

Practically all electrical products need to confirm to this set of tests as part of their “Type” test routine. This committee produces fire hazard testing documents in the IEC 60695 series of standards. These documents range from general guidelines on several fire hazard topics to specific instructions on how to build the test equipment needed to perform the tests. It’s interesting to see how some of these tests are carried out and the equipment used. Join me after the break as we take a look at that process.

Abnormal Heat — Ball Pressure Test

If your product gets really hot from a failure, will the enclosure safely contain the threat? IEC 60695-10-2 defines the test method and the associated test equipment needed to perform an abnormal heat test. The intent is to check that the insulating material does not deform or flow due to softening under elevated temperature and pressure so as to pose a safety hazard.

The equipment required to do this test consists of a 5 mm diameter steel ball which can be placed on the test sample such that a downward force of 20 N is applied. A heavy cylinder is used as a support platform to hold the test sample. The mass of the platform also helps prevent temperature variations during the test. Just under the flat surface of the platform, a drilled hole allows attaching a thermocouple probe to monitor the test temperatures, independent of the heating oven’s temperature control system.

Reticle Magnifier

The oven used is a regular laboratory or industrial oven, sufficiently large to hold the whole test apparatus and be able to maintain its internal temperature to within +/-2 °C up to a range of 200 °C. The last item required to complete the test setup is a means of measuring the indentation in the test sample after the test is over. A reticle magnifier — a x10 or x20 lens with a scale printed on it — is recommended in the standard, although a travelling (measuring) microscope can be used as well.

The test sample needs to be a 10 mm (square or circle) cut from the product being tested, and at least 2.5 mm thick. The platform and the ball pressure apparatus are placed in the oven until the whole mass achieves thermal equilibrium. The only variable in this test is the two different oven temperature settings used — either 75 °C or 125 °C — depending on how severe the expected conditions are for the product being tested. The test sample is then placed on the platform with the ball pressure apparatus bearing down on it. After an hour in the oven, the sample is removed, cooled to ambient temperature by dipping in water, dried, and the indentation produced by the ball pressure apparatus measured using the magnifier. The sample is declared acceptable if the diameter of the indentation on its surface does not exceed 2 mm.

Glowing/Hot-Wire Based Test Methods

The IEC 60695-2-x series is a range of standards that cover glow wire test methods. The Glow Wire test is used to check if an insulating material will catch fire when exposed to a hot or glowing piece of metal such as a heating element or an overheated piece of wire (caused by short circuit or overload). Additionally, the test is also used to verify if the test material will stop burning once the source of heat is removed — thus checking its self-extinguishing property.

The equipment used for the glow wire test is fairly complex, and IEC 60695-2-10 specifically describes just the construction of the apparatus, while the other three standards in this series cover the test methods and evaluation procedures for ascertaining flammability and ignition for materials and products.

A 4 mm diameter piece of Nichrome (Ni-Cr) wire is electrically heated via a low voltage transformer, capable of providing up to 200 Amps. The temperature of the Ni-Cr “glow wire” element is measured using a type ‘k’ thermocouple which is embedded inside a blind hole drilled in the tip of the glow wire element. Earlier versions of the standard specified a 0.5 mm diameter thermocouple. The present version requires a 1 mm diameter, with a fall back to 0.5 mm in case of doubts regarding the test measurements.

The glow wire temperature is manually set by adjusting the primary voltage of the transformer. No feedback control or re-adjustment of the heating current is allowed — the system is open loop. The test sample is then brought in contact with the glow wire element, usually by means of a sliding rail. The rail arrangement is such that the test sample presses against the glow wire with a force of 1 N and prevents it from penetrating more than 7 mm after initial contact.

The test sample is kept in contact with the glow wire for a duration of 30 sec. If it starts burning, a height gauge is used to record the maximum flame height. A piece of wood, covered in tissue paper, is placed 200 mm below the glow wire. Any falling particles of the test sample ought to self extinguish before they hit the paper/wood and not cause any charring. At the end of the 30 seconds, the test sample is moved away from the glow wire. Within another 30 seconds, the sample ought to stop burning, and any dripping material should not cause the tissue paper to get charred. Check out the video linked below.

Evaluation of the results is covered in the three remaining documents in this series and is not a simple pass/fail conclusion due to the numerous factors involved. The only variable in this test is the allowed test temperature, which ranges from 550 °C to 960 °C depending on the severity to which the test sample will be exposed in real world conditions.

The final test report will include a lot of data with the main information being the test temperature, the time when the sample starts burning after contact with the glow wire, the height of the flame and the time when the sample stops burning. A clear failure is when the sample continues to burn for more than 30 seconds after it is removed from contact with the glow wire — that’s a total of 60 seconds after the start of the test. Or if the tissue paper starts burning during the test.

Flame Test Methods

The IEC 60695-11-x series of Flame test methods and apparatus covers a range of flame tests at four separate intensity levels. These include the Needle Flame Test, a 50W flame test, a 500W flame test and a 1000W flame test. This set of tests goes a notch further from the glow wire tests by exposing the test samples directly to flames to verify that they will not propagate fire and are self-extinguishing.

The Needle flame test uses a 0.5 mm bore diameter needle burner supplied with either Butane or Propane gas. The flame height is adjusted to 12 mm using a flow control valve, and a gauge is used to verify the flame height. As in the glow wire test, a piece of wood covered with a tissue paper is used to check for flaming, dripping material. The variable in this test is the amount of time for which the flame is applied to the test sample, ranging from 5 sec. to 120 sec. As in the glow wire test, the sample is supposed to stop burning within 30 seconds after the flame source is removed. In case the test sample melts and drips, the needle burner can be tilted at a 45 ° angle to stay clear of the falling molten material.

Flame calibration is performed by measuring temperature rise using a 0.5 mm diameter ‘k’ type thermocouple with a small copper block crimped at its tip. When the measured temperature goes from 100 °C to 700 °C within 23.5 seconds, the system is considered calibrated for use.

The other tests in the IEC 60695-11-x series involve higher intensity flames and have similarities with the UL94 range of horizontal and vertical flame tests. They use more traditional flame sources such as laboratory Tirrill or Bunsen burners and we will possibly try to look at those tests in a future article.

These fire hazard tests are just three of the numerous tests that each product needs to pass through before it receives a mark of safety approval. It involves the work of the IEC, the national standards bodies, independent test laboratories and the manufacturers and their suppliers to ensure the products that reach the markets are safe to use.

Filed under: Engineering, Hackaday Columns

Friday Hack Chat: ASIC Design

พุธ, 03/15/2017 - 23:00

Join [Matt Martin], ASIC designer at Keysight, for this week’s Hack Chat.

Every week, we find a few interesting people making the things that make the things that make all the things, sit them down in front of a computer, and get them to spill the beans on how modern manufacturing and technology actually happens. This is the Hack Chat, and it’s happening this Friday, March 17, at noon PDT (20:00 UTC).

[Matt] has been working at Agilent / Keysight since 2007 as an ASIC designer. The work starts with code that is synthesized into logic gates. After that, [Matt] takes those gates and puts them into silicon. He’s worked with processes from 0.13um to 28nm. Turning code into silicon is still a dark art around here, and if you’ve ever wanted to know how all of this works, this is your chance to find out.

Here’s How To Take Part:

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging.

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Upcoming Hack Chats

We’ve got a lot on the table when it comes to our Hack Chats. On March 24th, we’re going to argue the merits of tube amplifiers in audio applications. In April, we have [Samy Kamkar], hacker extraordinaire, to talk reverse engineering.

Because I’ve never had the opportunity to do so, and because these Hack Chat announcement posts never get many comments anyway, I’m going to throw this one out there. What would it take to build out a silicon fabrication plant based on technology from 1972? I’m talking about a 10-micrometer process here, something that might be able to clone a 6502. Technology is on our side — a laser printer is cheaper than a few square feet of rubylith — and quartz tube heaters and wire bonding machines can be found on the surplus market. Is it possible to build a silicon fab in your garage without going broke? Leave your thoughts in the comments, and then bring them with you to the Hack Chat this Friday.

Filed under: Hackaday Columns

Surfing Like It’s 1998, The Dreamcast’s Still Got It!

พุธ, 03/15/2017 - 22:00

If you were a keen console gamer at the end of the 1990s, the chances are you lusted after a Sega Dreamcast. Here was a console that promised to be like no other, a compact machine with built-in PowerVR 3D acceleration (heavy stuff back then!), the ability to run Windows CE in some form, and for the first time, built-in Internet connectivity. Games would no longer be plastic cartridges as they had been on previous Sega consoles, instead they would come on a proprietary DVD-like Sega disc format.

It was a shame then that the Dreamcast never really succeeded in capitalizing on its promise. Everyone was talking about the upcoming Sony Playstation 2, and disappointing Dreamcast sales led Sega to withdraw both the console, and themselves from the hardware market entirely.

There remains a hard core of Dreamcast enthusiasts though, and they continue to push the platform forward.The folks at the Dreamcast Junkyard decided to go backwards a little when they resurrected the console’s dial-up modem to see whether a platform from nearly twenty years ago could still cut it in 2017. This isn’t as easy a task as you’d imagine, because, well, who uses dial-up these days? Certainly in the UK where they’re based it’s almost unheard of. They were able to find a pay-as-you go dial-up provider though, and arming themselves with the most recent Dreamkey V3.0 browser disc were able to get online.

As you might expect, the results are hilariously awful for the most part. Modern web sites that rely on CSS fail to render or even indeed to load, but retro sites like those in the Dreamcast community appear as they should. There is a video we’ve put below the break showing the rather tortuous process, though sadly they didn’t think to load the Hackaday Retro Edition. It does however feature the rarely-seen keyboard and mouse accessories.

This is something that commenters will no doubt agree is Not A Hack. But we’re huge retro hardware fans in these parts, so it’s likely that most readers will have a soft spot for the console. If like your scribe you were lucky enough to pull a fresh-from-launch Japanese-market Dreamcast from an airmail pouch so your employer could evaluate it before it landed in the rest of the world, especially so.

We’ve shown you a few Dreamcasts, including this portable console, and a failed Dreamcast repurposed as a guitar amplifier case. Please keep them coming!

Thanks [Tom Charnock].

Header image: Asim18 (Public domain).

Filed under: classic hacks

How An Oscilloscope Probe Works, And Other Stories

พุธ, 03/15/2017 - 21:01

The oscilloscope is probably the most versatile piece of test equipment you can have on your electronics bench, offering a multitude of possibilities for measuring timing, frequency and voltage as well as subtleties in your circuits revealed by the shape of the waveforms they produce.

On the front of a modern ‘scope is a BNC socket, into which you can feed your signal to be investigated. If however you simply hook up a co-axial BNC lead between source and ‘scope, you’ll immediately notice some problems. Your waveforms will be distorted. In the simplest terms your square waves will no longer be square.

Why is this? Crucial to the operation of an oscilloscope is a very high input impedance, to minimise current draw on the circuit it is investigating. Thus the first thing that you will find behind that BNC socket is a 1 megohm resistor to ground, or at least if not a physical resistor then other circuitry that presents its equivalent. This high resistance does its job of presenting a high impedance to the outside world, but comes with a penalty. Because of its high value, the effects of even a small external capacitance can be enough to create a surprisingly effective low or high pass filter, which in turn can distort the waveform you expect on the screen.

The answer to this problem is to be found in your oscilloscope probe. It might seem that the probe is simply a plug with a bit of wire to a rigid point with an earth clip, but in reality it contains a simple yet clever mitigation of the capacitance problem.

The circuit diagram of a typical passive oscilloscope probe. Ge ² [CC BY-SA 3.0]The majority of passive oscilloscope probes contain an attenuator to both isolate the circuit under test from the capacitance of the cable, and compensation capacitors in parallel with each of the resistances to cancel out the effect of the capacitance of the cable. The attenuator is usually chosen to divide the input voltage by ten, hence you will see “10x” probes. The reading on the ‘scope is then a tenth of the voltage at the probe, for example a 1 V level will measure as 100 mV. Many ‘scopes will automatically convert this to the true figure if their settings indicate the probe type.

The effect of a badly adjusted oscilloscope probe, a distorted square wave.

One of the compensation capacitors will be adjustable, to fine-tune the response. The ‘scope will have a calibrated square wave output, usually at 1 kHz, to which the probe is attached, and then the capacitor is adjusted until the wave displayed on the screen is truly square. Too much capacitance and the probe has the effect of a low-pass filter, while too little and it becomes a high-pass filter. It should become a semi-regular part of bench maintenance to check your probe against the calibration terminal, and to adjust it accordingly if the displayed waveform is not a square wave.


Highs and Lows

The probe is designed to present a high impedance to a circuit in situ, and not to distort the resulting displayed waveform. However there are times when it is necessary to measure an output that expects a low impedance, such as a 50 ohm source. In this situation the source must be terminated with the same impedance, so it should be fed into a 50 ohm resistor.

Some ‘scopes have a 50 ohm input mode, making this a matter of button pressing. Otherwise, a measurement can be made across the termination resistor, but since the impedance has now been reduced to a point at which small capacitances no longer have a significant effect, it becomes unnecessary if the cable to the oscilloscope is reduced to the barest minimum. In these cases you can dispense with the probe entirely if you have a BNC T-piece and a 50 ohm  terminator, and put both terminator and T-piece on the end of your cable directly coupled to the BNC socket on the ‘scope.

For many readers this basic primer on the operation of an oscilloscope input and probe will be old hat. But I remember my first oscilloscope, and how it gave me odd-looking results because I was too young to have been taught about probe compensation. When you get your first ‘scope it’s tempting to think that the ‘scope is the main event, without realising that it’s only as good as how you connect it to your circuit under test.

Filed under: Featured, slider, tool hacks

Mechanical Music Maker Throws Stones

พุธ, 03/15/2017 - 18:01

When we think of a xylophone we envision hitting the keys from above with mallets. But this robot instrument launches stones from below to play a tune. [Niel] calls the device a Pinger and it is part of a Rock Band — all instruments using rocks.

Although the original post has “xylophone” in it, this musical instrument is technically a glockenspiel because it uses metal keys instead of wood. Either way, it’s a work of art; the instrument’s creator ([Neil Mendoza]) was participating in Adobe’s Autodesk’s Pier 9 artist-in-residence program when he built it.

The keys were cut using a water jet, a process not easily in reach for most of us. But you could make do with a different process in a pinch. On the face of it, fabrication seems simple, but there’s software to calculate the right size for the keys depending on the material. The cuts need to be precise to yield an in-tune instrument.

The circular part is laser-cut acrylic, acting as a base for each key. Below the plate there is a cylinder positioned in the middle of the bar which keeps the stone from getting away. When the solenoid fires, the stone flies up and strikes the key, creating a ringing tone but also adding to the body of sound with a rattle when it falls back down to the base. The entire thing is driven by MIDI, so it can play a lot of tunes besides the biographical “Here Comes the Sun” (since, apparently, the pebbles are out in the sun). Check that out in the video below.

This couldn’t help but remind us of another solenoid-driven xylophone — whose keys were machined out of aluminum stock. There’s also the multixylophoniomnibus.

Filed under: musical hacks

This WAV File Can Confuse Your Fitbit

พุธ, 03/15/2017 - 15:01

As the devices with which we surround ourselves become ever more connected to the rest of the world, a lot more thought is being given to their security with respect to the internet. It’s important to remember though that this is not the only possible attack vector through which they could be compromised. All devices that incorporate sensors or indicators have the potential to be exploited in some way, whether that is as simple as sniffing the data stream expressed through a flashing LED, or a more complex attack.

Researchers at the University of Michigan and the University of South Carolina have demonstrated a successful attack against MEMS accelerometers such as you might find in a smartphone. They are using carefully crafted sound waves, and can replicate at will any output the device should be capable of returning.

MEMS accelerometers have a microscopic sprung weight with protruding plates that form part of a set of capacitors. The displacement of the weight due to acceleration is measured by looking at the difference between the capacitance on either side of the plates.

The team describe their work in the video we’ve put below the break, though frustratingly they don’t go into quite enough detail other than mentioning anti-aliasing. We suspect that they vibrate the weight such that it matches the sampling frequency of the sensor, and constantly registers a reading at a point on its travel they can dial in through the phase of their applied sound. They demonstrate interference with a model car controlled by a smartphone, and spurious steps added to a Fitbit. The whole thing is enough for the New York Times to worry about hacking a phone with sound waves, which is rather a predictable overreaction that is not shared by the researchers themselves.

We’ve covered an explanation of how MEMS accelerometers work before, as well as a look at air-gap exploits. There’s no need to worry too much about your devices with respect to this, but it’s a fascinating alternative method of input to keep in mind.

Thanks [Sterna] for the tip.

Filed under: peripherals hacks, phone hacks

Storing Data on a Single Atom

พุธ, 03/15/2017 - 12:00

In the electronics industry, the march of time brings with it a reduction in size. Our electronic devices, while getting faster, better and cheaper, also tend to get smaller. One of the main reasons for this is the storage medium for binary data gets smaller and more efficient. Many can recall the EPROM, which is about the size of your thumb. Today we walk around with SD cards that can hold an order of magnitude more data, which can fit on your thumb’s nail.

Naturally, we must ask ourselves where the limit lies. Just how small can memory storage get? How about a single atom! IBM along with a handful international scientists have managed to store two bits of information on two pairs of holmium atoms. Using a scanning tunneling microscope, they were able to write data to the atoms, which held the data for an extended period of time.

Holmium is a large atom, weighing in at a whopping 67 AMU. It’s a rare earth metal from the lanthanide series on the periodic table. Its electron configuration is such that many of the orbiting electrons are not paired. Recall from our article on the periodic table that paired electrons must have opposite spin, which has the unfortunate consequence of causing the individual magnetic fields to cancel. The fact that holmium has so many unpaired electrons makes it ideal for manipulation.

While you won’t be seeing atom-level memory on the next Raspberry Pi, it’s still neat to see what the future holds.

Thanks to [Itay] for the tip!

Via Gizmodo.

Filed under: news

Google Machine Learning Made Simple(r)

พุธ, 03/15/2017 - 09:00

If you’ve looked at machine learning, you may have noticed that a lot of the examples are interesting but hard to follow. That’s why [Jostmey] created Naked Tensor, a bare-minimum example of using TensorFlow. The example is simple, just doing some straight line fits on some data points. One example shows how it is done in series, one in parallel, and another for an 8-million point dataset. All the code is in Python.

If you haven’t run into it yet, TensorFlow is an open source library from Google. To quote from its website:

TensorFlow is an open source software library for numerical computation using data flow graphs. Nodes in the graph represent mathematical operations, while the graph edges represent the multidimensional data arrays (tensors) communicated between them. The flexible architecture allows you to deploy computation to one or more CPUs or GPUs in a desktop, server, or mobile device with a single API. TensorFlow was originally developed by researchers and engineers working on the Google Brain Team within Google’s Machine Intelligence research organization for the purposes of conducting machine learning and deep neural networks research, but the system is general enough to be applicable in a wide variety of other domains as well.

We’ve seen some bigger projects with TensorFlow before including robots. Of course, machine learning is all the rage right now. One Kickstarter for a machine learning book raised over a quarter of a million dollars. We hope it is going to be a really good book.

Filed under: Software Development, software hacks

Hush Those Old-Fashioned Phones

พุธ, 03/15/2017 - 06:00

Most people hate unsolicited calls, and it’s worse in the dead of night when we’re all trying to sleep. Smartphones are easy to configure to block nuisance calls, but what if you need a solution for your Plain Old Telephone System (POTS)? [Molecular Descriptor] has built a system to invisibly stop landline phones ringing after hours.

The basic principle relies on an analog circuit that detects the AC ringing signal from the phone network, and then switches in an impedance to make the phone company think the phone has been picked up. The circuit is able to operate solely on the voltage from the phone line itself, thanks to the use of the LM2936 – a regulator with an ultra-low quiescent current. It’s important if you’re going to place a load on the phone line that it be as miniscule as possible, otherwise you’ll have phone company technicians snooping around your house in short order wondering what’s going on.

The aforementioned circuitry is just to block the phone line. To enable the system to only work at night, more sophistication was needed. An Arduino Mega was used to program an advanced RTC with two alarm outputs, and then disconnected. The RTC is then connected to a flip-flop which connects the blocking circuit only during the requisite “quiet” hours programmed by the Arduino. The RTC / flip-flop combination is an elegant way of allowing the circuit to remain solely powered by the phone line in use, as they use far less power when properly configured than a full-blown microcontroller.

It’s a cool project, with perhaps the only pitfall being that telecommunications companies aren’t always cool with hackers attaching their latest homebrewed creations to the network. Your mileage may vary. For more old-school telephony goodness, check out this home PBX rig.

Filed under: phone hacks

Arpeggio – the Piano SuperDroid

พุธ, 03/15/2017 - 03:00

I never had the musical talent in me. Every now and then I would try to pick up a guitar or try and learn the piano, romanticising a glamorous career out of it at some point. Arpeggio – the Piano SuperDroid (YouTube, embedded below) sure makes me glad I chose a different career path. This remarkable machine is the brain child of [Nick Morris], who spent two years building it.

Although there are no detailed technical descriptions yet, at its heart this handsome robot consists of a set of machined ‘fingers’ connected to a set of actuators — most likely solenoids . The solenoids are controlled by proprietary software that combines traditional musical data with additional parameters to accurately mimic performances by your favourite pianists, right in your living room. Professional pianists, who were otherwise assuming excellent job security under Skynet, clearly have to reconsider now.

Along with incredible musical talent, Arpeggio is equipped with a set of omniwheels, allowing it to navigate around quite efficiently. This is not completely autonomous (yet). I cant wait to see the havok this robot causes if it were to go rogue.

[GIF credit: Gizmodo]

Filed under: robots hacks

Laser Cutting a 3D Printer

พุธ, 03/15/2017 - 01:31

The concept of self-replicating 3D printers is a really powerful one. But in practice, there are issues with the availability and quality of the 3D-printed parts. [Noyan] is taking a different approach by boostrapping a 3D printer with laser-cut parts. There are zero 3D-printed parts in this project. [Noyan] is using acrylic for the frame and the connecting mechanisms that go into the machine.

The printer design chosen for the project is the Prusa i3. We have certainly seen custom builds of this popular design before using laser-cut plywood for the frame. Still, these builds use 3D-printed parts for some of the more complicated parts like the extruder carriage and motor brackets. To the right is the X-carriage mechanism. It is complicated but requires no more than 6 mm and 3 mm acrylic stock and the type of hardware traditionally associated with printer builds.

With the proof of concept done, a few upgrades were designed and printed to take the place of the X-axis parts and the belt tensioner. But hey, who doesn’t get their hands on a 3D printer and immediately look for printable solutions for better performance?

We first saw a laser-cut RepRap almost nine years ago! That kit was going to run you an estimated $380. [Noyan] prices this one out at under $200 (if you know someone with a laser cutter), and of course you can get a consumer 3D printer at that price point now. Time has been good to this tool.

Filed under: 3d Printer hacks, tool hacks