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ถูกปรับปรุง 20 min 34 sec ก่อน

Awesome Illuminated Arcade Spinner

2 hours 2 minก่อน

[Tinker_on_Steroids] made some awesome looking spinners that not only light up when spun but are a really professional looking build on their own. Before we’d watched his assembly video we were sure he’d just added on to something he’d bought, but it turned out it’s all custom designed and made.

In case you’ve never played the old arcade games, a spinner is an input device for games such as Tempest or Breakout where you rotate a knob in either direction to tell the game which way and how fast to move something. In Tempest you rotate something around the middle of the screen whereas in Breakout you move a paddle back and forth across the bottom of the playing field.

He even detects rotation with a home-made quadrature encoder. For each spinner, he uses two ITR9608 (PDF) optical switches, or opto-interrupters. Each one is U-shaped with an LED in one leg of the U facing a phototransistor in the other leg. When something passes between the two legs, the light is temporarily blocked and the phototransistor detects it i.e. the switch turns off. When the thing moves away, the light is unblocked and it turns on again. The direction of movement is done by having the thing pass between two ITR9608’s, one after the other. The “things” that pass between are the teeth of a 3D printed encoder wheel.

To give it an extra awesome appearance he installed 4 NeoPixel LEDs in each spinner so that they glow blue when not spinning and then go from pink to red when spun up.

All the STL files for 3D printing it are on his Thingiverse project page, along with a BOM and links to where to buy parts. The brains for both spinners is an Arduino Pro Micro attached to one of the spinners using a custom-made shield. He also supplies the source and the hex code for the Arduino that makes the spinners appear as a USB mouse device when connected to a computer, unless of course you write your on code for them.

[Tinker_on_Steroids] did a very nice job designing all the 3D printed parts to make a professional looking spinner and if only for seeing a well designed DIY object, you should check out the first video after the break. The other two videos are demonstrations of it in action.

Long-time Hackday readers may remember these other DIY spinners, one of which uses an RC car tire for the knob and an optical encoder from a mouse. Some of the old photos are missing but the details are all there.

Thanks to [EVR] for the tip.


Filed under: misc hacks

Autopilots Don’t Kill Drivers, Humans Do

3 hours 31 minก่อน

The US National Highway Traffic Safety Administration (NHTSA) report on the May 2016 fatal accident in Florida involving a Tesla Model S in Autopilot mode just came out (PDF). The verdict? “the Automatic Emergency Braking (AEB) system did not provide any warning or automated braking for the collision event, and the driver took no braking, steering, or other actions to avoid the collision.” The accident was a result of the driver’s misuse of the technology.

This places no blame on Tesla because the system was simply not designed to handle obstacles travelling at 90 degrees to the car. Because the truck that the Tesla plowed into was sideways to the car, “the target image (side of a tractor trailer) … would not be a “true” target in the EyeQ3 vision system dataset.” Other situations that are outside of the scope of the current state of technology include cut-ins, cut-outs, and crossing path collisions. In short, the Tesla helps prevent rear-end collisions with the car in front of it, but has limited side vision. The driver should have known this.

The NHTSA report concludes that “Advanced Driver Assistance Systems … require the continual and full attention of the driver to monitor the traffic environment and be prepared to take action to avoid crashes.” The report also mentions the recent (post-Florida) additions to Tesla’s Autopilot that help make sure that the driver is in the loop.

The takeaway is that humans are still responsible for their own safety, and that “Autopilot” is more like anti-lock brakes than it is like Skynet. Our favorite footnote, in carefully couched legalese: “NHTSA recognizes that other jurisdictions have raised concerns about Tesla’s use of the name “Autopilot”. This issue is outside the scope of this investigation.” (The banner image is from this German YouTube video where a Tesla rep in the back seat tells the reporter that he can take his hands off the wheel. There may be mixed signals here.)

There are other details that make the report worth reading if, like us, you would like to see some more data about how self-driving cars actually perform on the road. On one hand, Tesla’s Autosteer function seems to have reduced the rate at which their cars got into crashes. On the other, increasing use of the driving assistance functions comes with an increase driver inattention for durations of three seconds or longer.

People simply think that the Autopilot should do more than it actually does. Per the report, this problem of “driver misuse in the context of semi-autonomous vehicles is an emerging issue.” Whether technology will improve fast enough to protect us from ourselves is an open question.

[via Popular Science].


Filed under: car hacks, news

Woodworking Basics for the Hardware Hacker

5 hours 1 นาทีก่อน

Hackaday is primarily a place for electronics hackers, but that’s not to say that we don’t see a fair number of projects where woodworking plays a key role. Magic mirror builds come to mind, as do restorations of antique radios, arcade machines built into coffee tables, and small cases for all manner of electronic and mechanical gadgets. In some of these projects, the woodworking really shines and makes the finished project pop. In others — well, let’s just say that some woodwork looks good from far, but is far from good.

Far be it from me to pass judgment on anyone else’s efforts – I can think of dozens of woodworking projects I’ve undertaken that were prosecutable as crimes against wood. But I do have a fair amount of experience with woodwork, having been in my dad’s shop and making sawdust from the time I could hold a handsaw. I’ve picked up a few things over the decades, and I thought I’d share a few tips that might help you combine your hardware hacks with woodwork that’ll make your project shine. I’ll gear this mainly to the novice woodworker, but there may be a few tips in here for the more experienced types too.

The Basics: Cutting Office side of my little “hack shack,” a prefabricated 10’x12′ shed. All the interior woodwork is mine except for the IKEA cabinets. I like wood.

One of the big problems with wood as a material is the perception that you need a lot of specialized tools to work effectively with it. While having a table saw is great, it also causes problems. A good saw is expensive, requires a lot of room, is noisy and dusty, and given the fact that a wrong move can sever an appendage, they’re intimidating to use. But there really is no substitute for the table saw for dimensioning rough stock, particularly when you need to perform a rip cut with the long grain of the wood. What to do?

I can think of a few ways around this issue, one that I face regularly these days, having sold my table saw prior to moving. The first is to avoid the issue altogether by taking advantage of pre-cut material. Most home centers have a decent selection of wood in a number of species, all available in multiple thicknesses and nominal widths from 2″ to 12″ (sorry, metric world — I’m sticking with imperial measurements because I have no idea how wood is measured in your system). You may have to compromise or change your design a bit to use off-the-rack stock, but there are few projects where you can’t hide a 1/2″ difference in width. I would use this strategy even when I had a table saw — just lazy, I guess.

But most of the wood in big-box stores is sold in 6′ to 10′ lengths, so you’re not going to be able to avoid cross-cutting stock for very long. You can leverage the store for a lot of this work as almost every one of them has a radial arm saw for chopping lumber to size. Usually cuts are a nominal charge after the first couple of free cuts, but be aware that most places have a disclaimer that they won’t do precision cuts. So if you need six pieces of 1×3 oak exactly 11-3/8″ long, you may be out of luck.

Harbor Freight’s entry-level miter saw. Source: Harbor Freight

So casual woodworkers might want to look at entry level miter saws for their cross-cutting needs. Harbor Freight gets a bad rap on its offerings, but at $89 for a 10″ compound miter saw, it’s hard to pass up even for a one-time job. Granted, a tool such as this is built to a price point and is not designed to survive the rigors of everyday job site use, but you’re not asking it to do that.

A miter saw is a game-changer for lots of small projects. Being able to cut wood to precise angles is the first step to all sorts of projects – it elevates your build beyond the simple butt joints that, while often functional, lack the visual appeal of a well-executed miter. A cheap miter saw might fight you a little there with some slop in the hard stops at 45°, but most can be adjusted for a perfect joint.

A miter saw is still a dusty, noisy beast that is best operated outdoors or in a dedicated shop, though. Don’t have the right space for one? Fear not — you can get a more than adequate miter with a manual miter saw. I’d stay away from the super-cheap wood or plastic miter boxes, though. A dedicated manual miter saw gets its precision from the frame the built-in saw rides in. They’re compact, quiet, easy to clean up after, and they can be had for $50 — not a bad tool to have even if a power miter saw already lives in your shop.

Simple Joinery

Once you’ve got your stock cut perfectly, how do you put the pieces together? This is where a lot of novice woodworkers trip up, and a few simple tools and techniques can get you past this problem. But first, you need to look at the forces the joint is going to experience in service. Many joints have almost no force on them. Picture frames are a good example – they just hang on the wall or sit on a desk. So just gluing the pieces together might be enough. But put that same miter joint into a box that needs to open and close a dozen times a day and a glued joint will fall apart in short order without some reinforcement.

Kreg pocket-hole jig. Source: Kreg Tools

There are tons of ways to reinforce a joint, starting with how the joint is cut in the first place. But if we’re not talking about fancy stuff like dovetails or mortise and tenon joinery, we’re probably going to need some sort of hardware to pull our joints together. That means brads, nails, or better still, screws.

For my money, the best investment the novice woodworker can make is a good pocket hole kit. Pocket hole joinery is another game changer. A jig clamps to the workpiece and allows you to drill a steeply angled hole at the edge of the wood, usually using a special stepped drill bit. The pocket guides a screw through one piece of stock into the other, with the depth of the hole and length of the screw carefully selected to avoid punching through.

Oak edge-banding on an MDF desktop. Oak pieces are pocket screwed together and held to the desktop with more pocket screws.

Fine joinery? Not by a long shot. Strong, fast, easy, and cheap? You bet. I’ve thrown together simple butt-jointed frames and sturdy cases with pocket screws in a matter of minutes. Miters are no problem either, and the instruction book that comes with most kits shows you all the wonderful things you can build. You have to be a little careful about hiding the pocket hole, or you can plug it afterward if you like. I just used pocket hole joinery to put a reinforcing edge band on some simple shelves for my new shop/office. Took me a few minutes (outside during a snowstorm) and it’s as good as it needs to be for the job it’ll do.

I’ve got a Kreg Jig K4 Master System which has served me well for years. At $150 retail it isn’t cheap, but the value is definitely there. If you want to start small, you can buy a simple kit with just a small jig, the stepped drill bit, and a square-head driver bit for the pocket screws for about $40. Fair warning, though: you’ll need a Vise-Grip face clamp to use the jig effectively.

Milling and Drilling

Novice woodworkers, especially those used to working with less compliant materials common in the machine shop, are often frustrated when they try to put holes in wood. Choose the wrong bit or use the wrong technique, and holes can end up looking pretty bad.

In general, the twist drills used for metalwork are not the best choice for through-holes in wood. They’re not the best choice for blind holes either, but you can get away with it if you’re careful. You’ll get better results using twist drills specifically designed for wood; these usually have a brad points in the center and spurs on the outside diameter; the brad point helps to keep the bit on target and the spurs cut the wood fibers cleanly for a smoother bore.

Large Forstner bit – like and end mill for wood. But use a drill press! Source: Traditional Woodworker.com

Larger diameter holes are best drilled with a spade bit. These also have brad points and spurs, but the cutting surface is flat and paddle-shaped, and the cutting method is more of a scraping action. A beefed up version of the spade bit, the Forstner bit, works in much the same way but can be used to drill angled holes; a spade bit has a fairly limited angle of acceptance to the stock before the flat blade starts bouncing off the wood. Think of a Forstner bit as an end mill for wood. Sort of.

Counterboring for mounting pot to a wood panel. I hogged out the wood to 1/8″ thick with a Forstner bit.

Except for the pilot hole drilled by the brad point, spade and Forstner bits can drill nearly flat-bottomed holes. But the pilot hole can be used to advantage when counterboring holes. This is especially useful for mounting switches, pots, and pilot lights in wood panels; the threaded shafts of such parts are rarely long enough to clear even a thin piece of stock. A large diameter bit is used to hog out enough space on the inside of the panel to clear the back of a control, while a clearance hole for the shaft is drilled through the first bit’s pilot. A drill press is best for such operations.

And one final drilling pro-tip: no matter what bit you use, always back up through-holes with a piece of waste wood, and clamp your stock to the waste block firmly. You won’t believe the difference that simple trick makes – holes will come out clean with no punch through to ruin your work.

I hope this encourages you to include wood in your projects. Good results only take a few basic tools, a little practice, and some guidance. And remember that all three of those and more are probably available at your local hackerspace. It might be worth a visit to see what folks are doing with wood and get some ideas.


Filed under: Hackaday Columns, Skills

Hackaday’s Sci-Fi Contest Hits Warp Speed

6 hours 38 secก่อน

Hackers’ perspiration may go into soldering, coding, and building. For many of us, the inspiration for these projects comes from science fiction. The books, movies, TV shows, short stories, and comics we all grew up on, and continue to devour to this day. We’re paying homage to all these great Sci-Fi stories with our latest contest.

The Sci-Fi Contest isn’t about the most efficient way of building a 555 circuit or the tightest code. This one is about celebrating science fiction in the best way we know how — building awesome projects. This is Hackaday, so you’re going to have to use some form of working electronics in your entry. Beyond that, it’s up to you. Bring us your Overwatch cosplays, your Trek Tricorders, your Star Wars pod racers.

This isn’t our first Sci-Fi contest. In fact, Sci-Fi was one of Hackaday.io’s first contests way back in 2014.
3 years and over 100,000 new hackers later, it’s time to take a fresh look at what you all have been up to. Projects that were entered in the first Sci-Fi contest are eligible, but you need to create a new project page and do some new work.

Check the rules for the full details. Once you’ve published a project use the drop-down menu on the left sidebar to enter it in the Hackaday Sci-Fi Contest.

Prizes

Great work reaps great rewards. Here’s what we’ve got for this contest:

  • Grand Prize is a Rigol DS1054Z 4 Channel 50 MHz scope.
  • First Prize is a Monoprice Maker Select Mini 3D printer
  • Second Prize is a complete Blu-Ray box of Star Trek: The Next Generation
  • Third Prize is Lego’s latest rendition of the Millennium Falcon.

The deadline is Monday, March 6, 2017, 09:00 pm PST (+8 UTC), so don’t waste time! Warm up your soldering irons, spin up your warp drives, and create something awesome!


Filed under: contests, Hackaday Columns

Robo-Flute Whistles MIDI

จันทร์, 01/23/2017 - 23:00

We aren’t sure this technically qualifies as music synthesis, but what else do you call a computer playing music? In this case, the computer is a Teensy, and the music comes from a common classroom instrument: a plastic recorder. The mistaken “flute” label comes from the original project. The contraption uses solenoids to operate 3D printed “fingers” and an air pump — this is much easier with a recorder since (unlike a flute) it just needs reasonable air pressure to generate sound.

A Teensy 3.2 programmed using the Teensyduino IDE drives the solenoids. The board reads MIDI command sent over USB from a PC and translates them into the commands for this excellent driver board. It connects TIP31C transistors, along with flyback diodes, to the solenoids via a terminal strip.

On the PC, a program called Ableton sends the MIDI messages to the Teensy. MIDI message have three parts: one sets the message type and channel, another sets the velocity, and one sets the pitch. The code here only looks at the pitch.

This is one of those projects that would be a lot harder without a 3D printer. There are other ways to actuate the finger holes, but being able to make an exact-fitting bracket is very useful. Alas, we couldn’t find a video demo. If you know of one, please drop the link in the comments below.

We have seen bagpipe robots (in fact, we’ve seen several). We’ve also seen hammering shotguns into flutes, which is certainly more melodious than plowshares.


Filed under: Arduino Hacks, ARM, musical hacks

Owning Hacker As A Word

จันทร์, 01/23/2017 - 22:01

To a casual observer it might seem as though our community is in the news rather a lot at the moment. It’s all about hacks on our TV screens in the soap opera of Washington politics, who hacked this, whether those people over there helped that lot hack the other lot, or even whether that person’s emails could have been hacked on that server. Keeping up with it as an outsider can become a full-time job.

XKCD 932 says it all. (CC BY-NC 2.5)

Of course, as we all know even if the mainstream journalists (or should I refer to them colloquially as “hacks”?) don’t, it’s not us they’re talking about. Their hackers are computer criminals, while we are people with some of the hardware and software skills to bend technology to our will, even beyond what its designers might have intended. And that divergence between the way we use the word in a sense of reappropriation and they use it in disapprobation sometimes puts us in an odd position. Explaining to a sober-suited businessman as the director of a hackspace, that no, we’re not *those*hackers can sometimes  feel like skating on thin ice.

Boot up or shut up! Hackers. Boot up or shut up! Yes, definitely, they absolutely nailed it. (Fair use), via Wikimedia Commons.

We’re all familiar with the sensationalized media portrayal of the hacker. Film characters who can develop and debug the most complex of code which breaks into Fort Knox or the Kremlin, all in about three seconds of aimless banging at a keyboard with a static mock-up of a command prompt in front of them. It’s become the subject of considerable mirth within our community, as with innumerable lists of awful hacking scenes in movies, photo galleries like this wonderful series of pages featuring stock photo “hackers”, or even the famous, and no doubt by now horribly burned, “Beautiful woman repair soldering a printed circuit board“. The trouble is though, behind the laughs at the awful tech portrayal is the sad truth, what is obviously fake to us looks real to Joe Public, and those are the criteria upon which we are judged. The credibility-stretching tech baddie on the screen is a hacker, they are told, so we must be baddies too.

Over Christmas where this is being written, the 2014 British film Pride was repeated on TV. In a memorable sequence the lead character explains the process of reappropriation of problematic language, as a tabloid newspaper insult against the gay community is turned against its originator by being adopted as the publicity slogan for a benefit gig. While the situation portrayed is very different, there is a valuable parallel to be drawn for any community in danger of losing control of their own narrative. In reclaiming the word “hacker” for our hackspaces, hackathons, and of course our popular and informative news websites, we are slowly educating the world that far from someone to be afraid of, a hacker is someone you might just welcome in your vicinity. Showing 3D printing or laser cutting in a hackspace to people from local businesses and organisations visibly opens their eyes on this front, having arrived looking wary they leave full of enthusiasm.

Something Done Without Constructive End

If we look at the word with several decades behind us, perhaps we can chart its fall into disreputable circles. Its early etymology is well-enough documented as a piece of the internal jargon at MIT’s Tech Model Railroad Club (TMRC), and it appears in Peter Samson’s 1959 TMRC dictionary to which he added italic notes in 2005.

HACK: 1) something done without constructive end; 2) a project under-taken on bad self-advice; 3) an entropy booster; 4) to produce, or attempt to produce, a hack3.

I saw this as a term for an unconventional or unorthodox application of technology, typically deprecated for engineering reasons. There was no specific suggestion of malicious intent (or of benevolence, either). Indeed, the era of this dictionary saw some “good hacks:” using a room-sized computer to play music, for instance; or, some would say, writing the dictionary itself.

Wardialling with a PDP-1, those were the days! The Tech, MIT’s newspaper, Nov. 20, 1963.

The word appears incidentally around that time in issues of The Tech, MIT’s newspaper, but we have to wait for November 1963 to see it break into the mainstream with a story of a group of students disrupting MIT’s phone system through wardialling with a PDP-1 (PDF link). Straight away we see the start of the association with computer crime, though there is an air of “Boys will be boys”, in the official reaction any approval is absent. (If by any chance any of that MIT class of ’63 whose nefarious activities are documented happens to be a Hackaday reader, we urge you to write your memoir of the escapades. We’d all like to read it so please get in touch!)

It’s entirely possible that our historical view is built on sand. We feel like “hack” as a term has been corrupted in our modern times and needs to be taken back to it’s original positive connotation. But there is an aspect of the 1959 TMRC use of “hack” having gained a negative connotation before ever leaving the confines of MIT. Perhaps only an etymologist or lexicographer could give us the answer, and even then it might have little relevance to our slow reappropriation of the word.

It’s a perennial in some hackspace circles, a few members bringing up the idea of replacing “hack” with something else a little less controversial. Some spaces go for it, ours where this is being written hasn’t. We hack, and we own it!


Filed under: Featured, History

Ice, Ice, Radio Uses FPGA

จันทร์, 01/23/2017 - 19:00

Building a software defined radio (SDR) involves many trades offs. But one of the most fundamental is should you use an FPGA or a CPU to do the processing. Of course, if you are piping data to a PC, the answer is probably a CPU. But if you are doing the whole system, it is a vexing choice. The FPGA can handle lots of data all at one time but is somewhat more difficult to develop and modify. CPUs using software are flexible–especially for coding user interfaces, networking connections, and the like) but don’t always have enough horsepower to cope with signal processing tasks (and, yes, it depends on the CPU).

[Eric Brombaugh] sidestepped that trade off. He used a board with both an ARM processor and an ICE FPGA at the heart of his SDR design. He uses three custom boards: one is the CPU/FPGA board, another is a 10-bit converter that can sample at 40 MSPS (sufficient to decode to 20 MHz), and an I2S DAC to produce audio. Each board has its own page linked from the main project.

You can find the C and Verilog sources for the device on GitHub. [Eric] also has a great block diagram and description of how everything works available. So far, the device can handle AM, synchronous AM, narrow-band FM, as well as upper and lower sideband (or both at once). It can also send raw IQ signals directly out for further processing.

Oddly enough, we haven’t talked about [Eric’s] design before, but a picture of it appeared in a past post about (among other things) the PMOD connector system (since the DAC uses PMOD as its interface). [Eric’s] device handles about 20 kHz of bandwidth at a time. If you want something more (also with an FPGA), check out FreeSRP.


Filed under: ARM, FPGA, radio hacks

4-way Or 8-way Joystick Restrictor Mod

จันทร์, 01/23/2017 - 16:00

Having a restricted 4-way or 8-way digital joystick for an arcade game is fine if the joystick is built into a game cabinet that plays only one game — 4-way for Pacman and 8-way for Super Cobra. But [Tinker_On_Steroids] wanted a joystick that could be restricted as either 4-way or 8-way for a cabinet that could play a multitude of games, and it had to switch from one type of restriction to the other automatically based on the selected game.

His digital joystick already came with a plate that can be mounted for either 4-way or 8-way restriction, but it has to be manually screwed in place for one or the other. He removed it and designed two 3D-printable parts, one that is to be mounted firmly to the bottom of the joystick and the other that rotates within the first one. Rotated in one orientation gives 4-way restriction and in the other orientation gives 8-way. That left only attaching a servo to do the rotation. The first video below shows mounting this all to the joystick and demoing the servo using a Teensy. The STL files for the parts are on his Thingiverse project page.

He also shows a simple circuit board he made that has two buttons and two LEDs on it for connecting to the Teensy and controlling the servo. And as an added option he shows how to talk to the Teensy from his desktop computer through USB and control the servo that way. In the second video below he details all that and also does a walk-through of the code he wrote for the Teensy. On the Thingiverse page he provides only the hex file but it’s likely you’d write your own software for interfacing with a game anyway.

[Tinker_On_Steroids] isn’t the only one who’s had to modify joysticks to get good gameplay on the old games. [Chris Osborn] had to make a modern USB gamepad work with his Apple II to get around problems with his old Apple joystick. Or maybe your joystick is getting worn out and needs fixing as [Frenetic Rapport] did for his Nintendo 64.

Thanks to [EVR] for the tip.


Filed under: toy hacks

A Violin Bow Lightsaber

จันทร์, 01/23/2017 - 13:00

[Bithead942]’s ten-year-old niece is a huge Star Wars fan, and also a violinist. Which of course has led her to learn to play some of the music from the film franchise, and then to ask her uncle to make her violin bow light up like a lightsaber.

His solution might seem fairly straightforward at first sight, simply attach a strip of DotStar addressable LEDs to a bow and drive them from an Arduino Pro Mini to gain the required animation of a saber power-up. But of course, there’s another dimension to this project. Not only does the bow have to do its lightsaber trick, it also has to be a playable bow. The electronics must not impede the musician by being too heavy or intrusive, but the result must have enough power in reserve to keep the lights burning for the duration of a performance.

After experimentation with AAA cells and CR2032s the power requirement was satisfied by a tiny Li-po cell attached to the top of the end of the bow with industrial Velcro, and the LED strip was glued and further secured using tiny rubber bands of the type used by orthodontists.

A short demonstration of the bow’s lightsaber action is shown below the break, we’re sure it’ll impress the young violinist’s audience.

We’ve covered a huge number of lightsaber projects over the years, of which the most impressive is probably this flame-based one. The musical angle on this one begs an interesting question for a very unmusical Hackaday scribe: could an orchestra produce a passable imitation of the sound of a lightsaber?


Filed under: musical hacks

Paper Toy Can Save Lives

จันทร์, 01/23/2017 - 10:00

Although there is a lot of discussion about health care problems in big countries like the United States, we often don’t realize that this is a “first world” problem. In many places, obtaining health care of any kind can be a major problem. In places where water and electricity are scarce, a lot of modern medical technology is virtually unobtainable. A team from Standford recently developed a cheap, easily made centrifuge using little more than paper, scrap material like wood or PVC pipe, and string.

A centrifuge is a device that spins samples to separate them and–to be effective–they need to spin pretty fast. Go to any medical lab in a developed country and you’ll find at least one. It will be large, heavy, expensive, and it will require electricity. Some have tried using hand-operated centrifuges using mechanisms like an egg beater or a salad spinner, but these don’t really move fast enough to work well. At the least, it takes a very long time to get results with a slow centrifuge.

[M. Saad Bhamla] and his colleagues at Stanford started brainstorming on this problem. They thought about toys that rotate, including a yo-yo. Turns out, those don’t spin all that fast, either. Then they considered a whirligig. We had forgotten what those are, but it is the real name for a toy that has a spinning disk and (usually) a string. When you pull on the string, the disk spins and the more you pull, the faster the disk spins. These actually have an ancient origin appearing in medieval tapestries and almost 2,500 years ago in China.

[Bhamla] found that how the toy worked was poorly understood (from a scientific standpoint)  and took pictures of one in operation with a high-speed camera. The team was able to create the “paperfuge”, a human-powered centrifuge that would spin at 125,000 RPM, enough to separate plasma from blood in under two minutes and isolate malaria parasites in 15. Some versions of the device could cost as little as twenty cents and don’t require anything more exotic than paper and string. You can see a video about the paperfuge, below.

Of course, there’s nothing to keep you from building a centrifuge like this yourself. It is cheap enough. The team made some versions using 3D printing, too. If you have a home lab and occasionally need a centrifuge, this might be your answer. It could be very helpful in a school setting, too, where students don’t have to share a single instrument.

Incidentally, [Manu Prakash] is a coauthor of this paper. He’s one of the Standford guys that brought us the $1 folding paper microscope a while back.

If you want something more involved (and less strenuous to operate), you can go open source but it won’t cost under a buck. Or you could get rid of that VCR you are hoarding under the bed.

Thanks [Rud] for the tip.


Filed under: Medical hacks, news

Hackaday Links: January 22, 2017

จันทร์, 01/23/2017 - 07:00

What is a 1971 Ford Torino worth? It depends, but even a 2-door in terrible condition should fetch about $7 or $8k. What is a 1971 Ford Torino covered in 3D printed crap worth? $5500. This is the first ‘3D printed car’ on an auction block. It looks terrible and saying ‘Klaatu Varada Nikto’ unlocks the doors.

Old Apple IIs had a DB19 connector for external floppy drives. Some old macs, pre-PowerPC at least, also had a DB19 connector for external floppy drives. These drives are incompatible with each other for reasons. [Dandu] has a few old macs and one old Apple II 3.5″ external floppy drive. This drive can be hacked so it works with a Mac Classic. The hack is simply disconnecting one of the boards in the drive, and it only reads 400 and 800kB disks, but it does work.

The US Army is working on a hoverbike. Actually, it’s not a hoverbike, because it doesn’t have a saddle or a seat, but it could carry 300 pounds at 60 mph. That’s 136,000 grams at 135 meters per second for the rest of the world out there. This ‘hoverbike’ will be used for very quick resupply, and hopefully a futuristic form of jousting.

Over the past few months, we’ve seen a few new microcontrollers built around the RISC-V core. The first is the HiFive1, a RISC-V on an Arduino-shaped board. The Open-V is another RISC-V based microcontroller, and now it too supports the Arduino IDE. That may not seem like much, but trust me: setting up the HiFive1 toolchain takes at least half an hour.

The NAMM show has been going on for the last few days, which means new electronic musical gear, effects pedals, and drum machines. This is cool, but somewhat outside our editorial prerogative. This isn’t. It’s a recording studio using a Rasberry Pi. Tracktion is working on a high-quality digital audio input and output add-on for the Pi 3. This is really cool, and you only need to look back at MPCs and gigantic Akai samplers from 15 years ago to see why.

Hey LA peeps. Sparklecon is next weekend. What’s Sparklecon? The 23B hackerspace pulls out the grill, someone brings a gigantic Tesla coil, we play hammer Jenga, and a bunch of dorks dork around. Go to Sparklecon! Superliminal advertising! Anyone up for a trip to the Northrop ham meetup next Saturday?


Filed under: Hackaday Columns, Hackaday links

Ping Pong Ball-Juggling Robot

จันทร์, 01/23/2017 - 04:00

There aren’t too many sports named for the sound that is produced during the game. Even though it’s properly referred to as “table tennis” by serious practitioners, ping pong is probably the most obvious. To that end, [Nekojiru] built a ping pong ball juggling robot that used those very acoustics to pinpoint the location of the ball in relation to the robot. Not satisfied with his efforts there, he moved onto a visual solution and built a new juggling rig that uses computer vision instead of sound to keep a ping pong ball aloft.

The main controller is a Raspberry Pi 2 with a Pi camera module attached. After some mishaps with the planned IR vision system, [Nekojiru] decided to use green light to illuminate the ball. He notes that OpenCV probably wouldn’t have worked for him because it’s not fast enough for the 90 fps that’s required to bounce the ping pong ball. After looking at the incoming data from this system, an algorithm extracts 3D information about the ball and directs the paddle to strike the ball in a particular way.

If you’ve ever wanted to get into real-time object tracking, this is a great project to look over. The control system is well polished and the robot itself looks almost professionally made. Maybe it’s possible to build something similar to test [Nekojiru]’s hypothesis that OpenCV isn’t fast enough for this. If you want to get started in that realm of object tracking, there are some great projects that make use of that piece of software as well.


Filed under: robots hacks

Newton’s Cradle for Those Too Lazy to Procrastinate

จันทร์, 01/23/2017 - 01:00

Desk toys are perfect for when you don’t want to work. There’s a particularly old desk toy called the Newton’s cradle. If you don’t know the name, you’d still recognize the toy. It is some ball bearings suspended in midair on strings. If you pull back, say, two balls and let them swing to impact the other balls, the same number of balls on the other side will fly out. When they return, the same number will move on the other side and this repeats until friction wears it all down.

We think [JimRD] might be carried away on procrastination. You see, he not only has a Newton’s cradle, he has automated it with an Arduino. According to [Jim], this is his third attempt at doing so. You can see the current incarnation in the video, below.

There are two servos. One pulls back the balls and releases them and the other stops the balls in anticipation of the next operation. The servo that pulls the balls back is clearly magnetic. At first, we thought it was an electromagnet and that deenergizing it released the balls. That’s not the case. Instead, the servo arm has a permanent magnet, but foam decouples it from the ball so that if the arm pulls far enough away, the ball can escape.

Because of the differences in magnets, ball bearings, and other factors, if you try to duplicate this, you’ll probably have to experiment a little with the angles and speeds in the code. The ball stop servo is probably unnecessary, as long as you don’t mind waiting for the thing to wind down on its own.

If you don’t have a cradle, you could always make one yourself. We’d probably avoid using light bulbs, though.


Filed under: Arduino Hacks

An Eight Inch Floppy For Your Retrocomputer

อาทิตย์, 01/22/2017 - 23:30

For people under a certain age, the 8 inch floppy disk is a historical curiosity. They might just have owned a PC that had a 5.25 inch disk drive, but the image conjured by the phrase “floppy disk” will be the hard blue plastic of the once ubiquitous 3.5 inch disk. Even today, years after floppies shuffled off this mortal coil, we still see the 3.5 inch disk as the save icon in so many of our software packages.

For retro computing enthusiasts though, there is an attraction to the original floppy  from the 1970s. Mass storage for microcomputers can hardly come in a more retro format. [Scott M. Baker] evidently thinks so, for he has bought a pair of Qume 8 inch floppy drives, and interfaced them to his CPM-running RC2014 Z80-based retrocomputer.

He goes into detail on the process of selecting a drive as there are several variants of the format, and interfacing the 50 pin Shuggart connector on these drives with the more recent 34 pin connector. To aid in this last endeavour he’s created an interface PCB which he promises to share on OSH Park.

The article provides an interesting insight into the control signals used by floppy drives, as well as the unexpected power requirements of an 8 inch drive. They need mains AC, 24VDC, and 5VDC, so for the last two he had to produce his own power supply.

He’s presented the system in a video which we’ve put below the break. Very much worth watching if you’ve never seen one of these monsters before, it finishes with a two-drive RC2014 copying files between drives.

We’ve had surprisingly few 8 inch floppies here on Hackaday, probably because they never really made it into home computers. We did however review the RC2014 last year, as well as looking at [Scott]’s original build.


Filed under: classic hacks

The Impressive Z80 Computer With The Unfortunate Name

อาทิตย์, 01/22/2017 - 22:00

We’ve seen a lot of retro builds around the Z80. Not many are as neatly done or as well-documented as [dekeNukem’s] FAP80 project. Before you rush to the comments to make the obvious joke, we’ll tell you that everyone has already made up their own variation of the same joke. We’ll also tell you the name is a cross between an old design from [Steve Ciarcia] called the ZAP80 and a reference to the FPGA used in this device.

[dekeNukem] says his goal was to create a Z80 computer without all the baggage of using period-correct support chips. You can argue about the relative merits of that approach versus a more purist build, but the FAP80 has a 5 slot backplane, VGA output, a PS/2 keyboard port and more. You can see one of many videos showing the machine below.

The machine started out hand-wired but because of noise issues, it is now on a printed circuit board. In addition to the GitHub page, there is an extensive set of blog posts with videos detailing the machine’s design and construction. Not all the blog postings are tagged so you might have to look around a little, but there is a lot of detail about the project. If the blog postings aren’t your thing, there’s a sort of visual tour, too.

You could argue that a Z80 computer that uses an FPGA, a CPLD, and two ARM chips for support is a little strange, but it does make for a powerful and simple system. However, we’ve seen other Z80 systems supported by more modern devices. We suppose, though, that you could just simulate the whole thing in an FPGA or bigger CPU.


Filed under: ARM, FPGA, Microcontrollers

Stuff An Android In Your Xbox Controller’s Memory Slot

อาทิตย์, 01/22/2017 - 19:00

What is this, 2009? Let’s face facts though – smartphones are computing powerhouses now, but gaming on them is still generally awful. It doesn’t matter if you’ve got the horsepower to emulate any system from the last millennium when your control scheme involves awkwardly pawing away at glass when what you need is real buttons. You need a real controller, and [silver] has the answer – a 3D printed phone mount for the original Xbox Controller.

It’s more useful than it initially sounds. The original Xbox used USB 1.1 for its controllers. With a simple OTG cable, the controllers can be used with a modern smartphone for gaming. The simple 3D printed clamp means you can have a mobile gaming setup for pennies – old controllers are going cheap and it’s only a couple of dollars worth of filament. The trick is using the controller’s hilariously oversized memory card slots – for some reason, Microsoft thought it’d be fun to repackage a 64MB flash drive into the biggest possible form factor they could get away with. The slots also acted as a port for online chat headsets, and finally in 2017, we’ve got another use for the form factor.

For the real die-hard purists, [silver] also shares a photo of a similar setup with a Nintendo 64 controller – including a big fat USB controller adapter for it, hanging off the back. Not quite as tidy, that one.

It’s a neat little project – we love to see useful stuff built with 3D printers. If you’ve been looking for something functional to print, this is it. Or perhaps you’d like to try these servo-automated 3D printed light switches?


Filed under: 3d Printer hacks

Vive Tracker Brings Easier VR Hacking

อาทิตย์, 01/22/2017 - 16:00

CES 2017 is over and there were VR gadgets and announcements aplenty, but here’s an item that’s worth an extra mention because it reflects a positive direction we can’t wait to see more of. HTC announced the Vive Tracker, to be released within the next few months.

The Tracker looks a bit like a cross between a hockey puck and a crown. It is a self-contained, VR trackable device with a hardware port and built-in power supply. It can be used on its own or attached to any physical object to make that object trackable and interactive in VR. No need to roll your own hardware to interface with the Vive’s Lighthouse tracking system.

Valve have been remarkably open about the technical aspects of their hardware and tracking system, and have stated they want to help people develop their own projects using the system. We’ve seen very frank and open communication on the finer points of what it took to make the Lighthouse system work. Efforts at reverse-engineering the protocol used by the controller even got friendly advice. For all the companies making headway into VR, Valve continues to be an interesting one from a hacking perspective.

[Image source for bottom of Tracker: RoadToVR]

 


Filed under: Virtual Reality

Heavy Metal Chess

อาทิตย์, 01/22/2017 - 13:00

Chess is a slow game of careful decision-making, looking several moves ahead of the current state of the board. So is machining, and combining the two is an excellent way to level up your machine shop chops. And so we have the current project from [John Creasey] who is machining a chess set out of stainless steel.

This isn’t that new-fangled computer numerical control at work, it’s the time-tested art of manual machining. Like chess, you need to plan several steps ahead to ensure you have a way to mount the part for each progressive machining process. In this first video of the series [John] is milling the knights — four of them, with two which will eventually get a black oxide treatment.

Milling the horse head is fun to watch, but you’ll be delighted when the work gets to the base. [John] is using a pipe fitting as a fixture to hold the already-milled horse-head-end while working the base on his lathe. The process begins by getting rid of the inner threads, then working the pipe fitting very carefully to the diameter of the chess piece for a perfect press fit. Neat!

At the end, [John] mentions it took “quite a few months of weekends to get to this point” of having four pieces made. They look great and we can’t wait to see the next piece in the set come to life. You’ll find the video embedded below, but if you can’t sink this kind of time into your own chess set, you may try three-dimensional laser cut acrylic pieces.

[via /r/metalworking]


Filed under: misc hacks

Taking Control Of Your Furby

อาทิตย์, 01/22/2017 - 10:00

Furbys have been around for a while and they are an interesting (if annoying) toy that will teach the kids to be okay with their eventual robotic overlords. In the meantime, the latest version of the robotic companion/toy/annoyance uses Bluetooth LE to communicate with the owner and [Jeija] has been listening in on the Bluetooth communication, trying to reverse engineer the protocol in order to run code on Furby.

[Jeija] has made a lot of progress and can already control the Furby’s actions, antenna and backlight color, and change the Furby’s emotional state by changing the values of the Furby’s hungriness, tiredness, etc. [Jeija] has created a program that runs on top of Node.js and can communicate with the Furby and change its properties. [Jeija] has also discovered, and can bring up, a secret debug menu that displays in the Furby’s eyes. Yet to be discovered is how to run your own code on the Furby, however, [Jeija] is able to add custom audio to the official DLC files and upload them into the Furby.

[Jeija] points out the all this was done without taking a Furby apart, only by sniffing the Bluetooth communication between the robot and the controlling app (Android/iOS device.) Check out a similar hack on the previous generation of Furbys, as well as a replacement brain for them. We just hope that the designers included a red/green LED so that we will all know when the Furbys switch from good to evil.


Filed under: robots hacks, toy hacks

Remote Controlling A Dog

อาทิตย์, 01/22/2017 - 07:00

Until the industrial revolution, humans made use of animals to make our labor easier. This is still seen in some niche areas, like how no machine yet has been invented that’s as good at sniffing out truffles as pigs are. [William] has hearkened back to humanity’s earlier roots, but in a more modern twist has made something of a general purpose dog that could feasibly do any work imaginable. Now his dog is remote-controlled.

[William] accomplished the monumental task in a literally cartoonish fashion using the old trope of hanging a hot dog in front of something’s face to get them to chase it. The attachment point was fitted with a remote control receiver and an actuator to get the hanging hot dog to dangle a little bit more to the dog’s right or left, depending on where the “operator” wants the dog to go. [William]’s bulldog seems to be a pretty good sport about everything and isn’t any worse for wear either.

Believe it or not, there has been some actual research done into remote controlling animals, although so far it’s limited to remote-controlled cockroaches. We like the simplicity of the remote-controlled dog, though, but don’t expect to see these rigs replacing leashes anytime soon!

 


Filed under: wireless hacks