Syndicate content Hackaday
Fresh hacks every day
ถูกปรับปรุง 4 hours 28 min ก่อน

Hackaday Prize Entry: Engine Control Units and Arduinos

6 hours 14 minก่อน

The modern internal combustion engine is an engineering marvel. We’re light-years ahead of simple big blocks and carburetors, and now there are very fast, very capable computers sensing adjusting the spark timing, monitoring the throttle position, and providing a specific amount of power to the wheels at any one time. For the last few years [Josh] has been building a fully-featured engine management system, and now he’s entered it in the Hackaday Prize.

The Speeduino project is, as the name would suggest, built around the Arduino platform. In this case, an Arduino Mega. The number of pins and PWMs is important — the Speeduino is capable of running the fuel and ignition for eight cylinder engines.

The Speeduino is designed to do everything an engine control unit can do, including rev limiting (although if you’re building your own ECU, why?), and reading ethanol sensors. Right now [Josh] is working on a beta run of the Speeduino designed for the 1.6L Miata. That’s an excellent platform for firmware performance tuning, and there’s still a lot of work to be done on the firmware side of things before everything’s all set to go. Still, this is a great project and sure to impress the bros at track day, bro.

The HackadayPrize2017 is Sponsored by:
Filed under: Engine Hacks, The Hackaday Prize

Reamer Regrinding Using a Toolpost Spindle

9 hours 14 minก่อน

How often have you wished you could reduce the size of a drillbit? [Ben Katz] has a bunch of projects in mind that use a tight-tolerance 22mm bore–but he didn’t have a 22mm reamer handy. Rather than buy one, he thought, why not regrind a larger one to the right size?

He first ground down the shank to fit in the lathe’s drill chuck. Once it was loaded into the chuck,  he reground the edge of a 7/8″ (22.225mm) reamer, reducing its diameter down to 22mm by spinning it on his lathe in conjunction with a toolpost spindle with a grinding wheel attached. The final diameter was 21.995mm—off by 5 microns!

[Ben]’s homebuilt spindle is a cool project in itself, and we publish a lot of posts about those handy tools. Check out our pieces on a brushless DC motor used as a CNC spindle, and this 3D printer outfitted with a spindle. Also check out [Ben]’s electric tricycle build we featured a few years ago.

Filed under: hardware, tool hacks

Logic Gates Under (Air) Pressure

เสาร์, 08/19/2017 - 21:00

We’ve always been fascinated at the number of ways logic gates can spring into being. Sure, we think of logic gates carrying electrons, but there are so many other mechanical means to do the same thing. Another method that sometimes has a practical use is fluidic or pneumatic logic. We guess [dAcid] has a similar interest since he’s written two posts on how to construct the gates. One post covers making them with ordinary tools. The other requires an SLA printer.

According to [dAcid], the design is effectively the same either way, but the SLA printing is more precise. Silicone is an important component, either way. Fluidic logic has applications in some mechanical systems, although digital logic has made it less important than it once was. However, it is very possible that nanotechnology systems will implement logic mechanically, so this is still an interesting technique to understand. You can see videos of how a D latch looks using both methods, below.

The idea is simple. A fluid — keeping in mind that air can be a fluid — is sent into a tube that splits into a “Y” or “T” shape (see figure, below). Small control tubes that are perpendicular to the main flow can force the flow down one leg of the Y or the other. In the case of the figure, O1 and O2 are the branches of the “T” with C1 and C2 allowing control of the direction of flow. There are other variations, including using a vacuum and a pressure on one port to move the main flow and the implementation of basic building blocks.

You might wonder how you can make logic gates out of this until you realize it is nothing more than a demultiplexer. Some FPGAs use multiplexers to implement logic in a regular way, and the idea is the same here. Incidentally, you can view a relay as a mux, as well, and do the same techniques.

In fact, it is surprising just how many ways there are to make logic gates if you try. We are often amused to think that if the Egyptians had used the Nile for pneumatic pressure, they probably had the brick-making technology that the pyramids could have been the first data centers. You can only wonder what they would have computed if they had thought about it.

You can make purely mechanical gates, too. If you have a laser cutter, you are all set.

Filed under: news

Project Kino: Robotic Jewelry And Tech Accessory

เสาร์, 08/19/2017 - 18:00

Researchers from MIT and Stanford are taking the ‘person’ in ‘personal assistant’ to mean something more literal with these robots that scurry around on the user’s clothing.

Project Kino — inspired by living jewelry — are robotic accessories that use magnetic gripping wheels on both sides of the clothing to move about. For now they fill a mostly aesthetic function, creating kinetic accents to one’s attire, but one day they might be able to provide more interactive functionality. They could act as a phone’s mic, adjust clothing to suit the weather, function as high-visibility wear for cyclists or joggers, as haptic feedback sensors for all manner of applications (haptic sonar bodysuit, anyone?), assemble into large displays, and even function as a third — or more! — hand are just the tip of the iceberg for these ‘bots.

Size and the 45 minute battery life are limiting factors at present — both addressable down the line — but a wireless charging station on the user’s person that the robots can top up at is an intermediate solution. In addition, the complex 3D mapping of the user’s person is a bit too much for the Rovables’ microprocessors, so they are only partially autonomous and limited in their movement for now. Still, a personal swarm of these assistant-accessories sounds like some seriously cool near-future tech.

[Thanks for the tip, Itay!]

Filed under: robots hacks, wearable hacks

Fresh-Pressed Clothes Courtesy of TEO, the Iron Man

เสาร์, 08/19/2017 - 15:00

As with many tasks, robots may soon be ironing our clothes for us before we leave for work. Built by a team from the University Carlos III de Madrid’s robotics lab in Getafe, Spain, TEO is a highly articulated robot, that can climb stairs, open doors, and has recently added ironing to its skill set.

Data from a depth-sensing camera in TEO’s head is combed over by an algorithm, breaking it down into thousands of points — 0 being smooth and 1 a defined line in the clothing. Comparing those point values to those of its neighbours allows TEO to identify wrinkles without any preexisting notion of what a freshly-pressed garment looks like.

Once the offending wrinkles have been identified, the information is passed to TEO’s other processes and get the job done. It doesn’t yet know how to differentiate between a wrinkle and other features like a zipper, and it takes a while to complete it’s chore — both of which can be a hazard when ironing — but that’s only a matter of time.

Folding said laundry however, is a bit further away, so it may be easier to enlist the help of the internet of things to help with the chore in the meantime.

[Thanks for the tip, Itay!]

Filed under: home hacks, robots hacks

It’s an Angle Grinder! No, it’s a Floor Sander!

เสาร์, 08/19/2017 - 12:00

Faced with the potentially arduous task of sanding a wood floor, what would you do? Hire a pro? Rent the proper tools and do it yourself? Perhaps even shell out big bucks to buy professional grade tools? Or would you root around in your junk pile and slap together a quick and dirty floor sander from an old angle grinder?

That’s what [Donn DIY] did when looking at the wide expanse of fresh floorboards in his new sauna. Never one to take the easy way out, and apparently with a thing for angled gear boxes, [Donn DIY] took the guts out of a burnt-out angle grinder for his impromptu floor sander. A drill attached to the old motor rotor provides the spin, and a couple of pieces of scrap wood make the platen. Sandpaper strips are clamped between the discs, and as seen in the video below, the whole contraption does an admirable job.

We’ve seen lots of angle grinder hacks before, some useful, some silly. This one gets the job done and is a nice quick hack that speaks to the value of a well-stocked junk pile.

Filed under: tool hacks

PiCorder: Raspberry Pi Stands in for Stone Knives and Bearskins

เสาร์, 08/19/2017 - 09:00

In a classic episode of Star Trek, Spock attempts to get data from a tricorder while stuck in the 1930s using what he described as “stone knives and bearskins.” In reality, he used vacuum tubes, several large coils, and a Jacob’s ladder. Too bad they weren’t in the year 2017. Then Spock could have done like [Directive0] and used a Raspberry Pi instead. You can see the result in the video below.

The build starts with a Diamond Select Toys model tricorder. The Raspberry Pi, a battery, a TFT screen, and a Pi Sense Hat make up the bulk of the build.

Truthfully, this is one of those projects that isn’t rocket science (or perhaps warp core engineering) electronically. It is just stringing together some off-the-shelf modules with Python code. But the refitting of the toy tricorder is where the real story is and the video shows details of how it all goes together.

We have seen quite a few duplicates of the next generation tricorder. We’ve also seen devices that claim to be tricorders even though they don’t always look like any we’ve ever seen. We live in a world where hoverboards don’t hover and AI assistants aren’t really that smart. So I guess we can overlook that none of these tricorders can really do half of what the ones on Star Trek could do.

Filed under: Raspberry Pi, toy hacks

Apple’s Secure Enclave Processor (SEP) Firmware Decrypted

เสาร์, 08/19/2017 - 06:01

The decryption key for Apple’s Secure Enclave Processor (SEP) firmware Posted Online by self-described “ARM64 pornstar” [xerub]. SEP is the security co-processor introduced with the iPhone 5s which is when touch ID was introduced. It’s a black box that we’re not supposed to know anything about but [xerub] has now pulled back the curtain on that.

The secure enclave handles the processing of fingerprint data from the touch ID sensor and determines if it is a match or not while it also enables access for purchases for the user. The SEP is a gatekeeper which prevents the main processor from accessing sensitive data. The processor sends data which can only be read by the SEP which is authenticated by a session key generated from the devices shared key. It also runs on its own OS [SEPOS] which has a kernel, services drivers and apps. The SEP performs secure services for the rest of the SOC and much more which you can learn about from the Demystifying the Secure Enclave Processor talk at Blackhat

[xerub] published the decryption keys here. To decrypt the firmware you can use img4lib and xerub’s SEP firmware split tool to process. These tools make it a piece of cake for security researchers to comb through the firmware looking for vulnerabilities.

Filed under: iphone hacks, security hacks

Live Stream to YouTube by Pointing a Box and Pressing a Button

เสาร์, 08/19/2017 - 03:01

YouTube has the ability to do live streaming, but [Tinkernut] felt that the process could be much more straightforward. From this desire to streamline was born the Raspberry Pi based YouTube live streaming camera. It consists of a Raspberry Pi with some supporting hardware and it has one job: to make live streaming as simple as pointing a box and pressing a button. The hardware is mostly off-the-shelf, and once all the configuration is done the unit provides a simple touchscreen based interface to preview, broadcast live, and shut down. The only thing missing is a 3D printed enclosure, which [Tinkernut] says is in the works.

Getting all the software configured and working was surprisingly complex. Theoretically only a handful of software packages and functionality are needed, but there were all manner of gotchas and tweaks required to get everything to play nice and work correctly. Happily, [Tinkernut] has documented the entire process so others can benefit. The only thing the Pi is missing is a DIY onboard LED lighting and flash module.

Filed under: digital cameras hacks, how-to, Raspberry Pi

Hackaday Prize Entry: Archelon ROV Explores the Ocean

เสาร์, 08/19/2017 - 01:30

Acendtech Robotics is a 4H robotics club located in Freehold, NJ, and their centerpiece project is the Archelon, an underwater drone they built out of PVC pipes. It’s also a Hackaday Prize entry designed to monitor marine traffic, the seabed, piers, jetties, and other underwater constructions.

The Archelon uses eight thrusters constructed out of bilge pumps that have been hacked to add a propeller, leaving the motor sealed safely inside.

The ROV’s motors are controlled by an Arduino Mega along with two motor driver boards, each board driving two pairs of DC motors. There’s also a robot claw rotated by another modified bilge pump, opened and closed by a waterproof servo. The on-board electronics including a Teensy 3.2 are sealed inside a 1/2″ acrylic tube sealed with rubber o-rings and custom-milled stainless steel endcaps. Connected to the Teensy are the ROV’s cameras as well as an ATTiny88, which in turn control the motors.

Students working with the Archelon learn not only the technical aspects of building a ROV like assembly and programming, but also its mission, learning how to take test samples of agar to study pollutants in the maritime environment.

The HackadayPrize2017 is Sponsored by:
Filed under: The Hackaday Prize

Retrotechtacular: Olivetti Net3

เสาร์, 08/19/2017 - 00:01

If you sign up for a European hacker camp such as CCC Camp in Germany or SHA Camp in the Netherlands, you’ll see among the items recommended to take with you, a DECT handset. DECT, or Digital Enhanced Cordless Telecommunications, refers to the set of standards that lie behind the digital cordless telephones that are ubiquitous across Europe and some countries elsewhere in the world. These standards cover more than just the simple two-way telephone calls through a base station that most Europeans use them for though, they define a fully functional multi-cell 3G phone and data networking system. This means that an event like SHA Camp can run its own digital phone network without having to implement cell towers.

Olivetti promotional Net3 image

Reading the history of DECT, there is the interesting snippet that the first DECT product on the market in 1993 was not a telephone but a networking device, and incidentally the first wireless LAN product on the European market. Olivetti’s Net3 provided 512kB/s wireless networking to a base station with Ethernet or Token Ring interfaces for connection to a LAN. In its original form it was an internal card for a desktop PC coupled to a bulky external box containing radio circuitry and antenna, but its later incarnations included a PCMCIA card with a much smaller antenna box. The half-megabit speed seems tiny by today’s standards, but in the pre-multimedia world of 1993 would have been perfectly adequate for a Novell Netware fileserver and an HP Laserjet 4.

[Heinz Wolff] swallows a condom in another Olivetti promotional image. Mystery Technology

So DECT is an interesting technology that can do more than just a simple cordless phone, and its first product was unexpectedly somewhat groundbreaking. It then becomes even more interesting to find that Net3 has left very little evidence of itself to find that can be found on the Web, and learning more about it requires a little detective work.

The Wikipedia entry has the bare bones, but it speaks volumes about the obscure nature of the product that the encyclopedia’s only picture of it is a tiny thumbnail-sized promotional image of the PCMCIA variant in a chunky mid-1990s laptop. A further search reveals a 1993 British Olivetti staff newsletter (PDF) carrying another promotional image of the desktop Net3 device featuring the then-well-known TV personality and academic [Heinz Wolff] demonstrating the technology bizarrely by swallowing a DECT medical instrumentation transponder wrapped in a condom. Some press releases remain in the fossilized remnants of the 1990s internet, and a Net3 design team member’s LinkedIn page led us to the patent covering the system, but that’s pretty much it. We can’t even find a high enough resolution image of a Net3 card for our featured image slot.

Wireless Things Before Their Time

It’s obvious that Net3 and DECT networking as a high-end wireless LAN before a need for wireless LANs existed never made it, but what is perhaps more interesting is that it seems to have left no legacy for other more mundane applications. We are in the midst of an explosion of hype around the Internet of Things and it seems new short-range wireless networking technologies appear almost daily, yet the world seems to have overlooked this robust, low power, and mature wireless network with its own dedicated frequency allocation that many of us already have in our homes. It seems particularly surprising that among the many DECT base stations on sale at your local consumer electronics store there are none with an Internet connection, and there is no market for IoT devices that use DECT as their backhaul.

In the open-source community there has been some work on DECT. The OsmocomDECT project for example provides a DECT software stack, and deDECTed.org states an aim to “better understand DECT and its security and to create an Open Source implementation of the DECT standard”. But there seems to have been very little hardware work in our community on the standard, for example there are no DECT-specific projects on Hackaday.io.

Net3 then was a product before its time, a herald of what was to come, from that twilight period when the Web was definitely a thing but had yet to become the world’s universal information repository. Public wireless networking was still several years in the future, so there was no imperative for road warriors to equip themselves with a Net3 card or for computer manufacturers — not even Olivetti themselves! — to incorporate the technology. It thus didn’t take the world by storm, and unusually for such a ground-breaking computer product there remains little legacy for it beyond a rarely-used feature of the protocol Europeans use for their cordless phones.

Did you have a Net3 card? Do you still have one? Let us know in the comments.

Filed under: History, phone hacks, Retrotechtacular

Latskap Semi-Automatic Liquor Cabinet

ศุกร์, 08/18/2017 - 22:30

A well-stocked liquor cabinet is a necessity for the classy gentleman or gentlelady who likes to entertain. Having the proper spirits and mixers on hand to make anything from a martini to a sidecar is always a solid way to ensure guests have a good time at your cocktail party. In the past, a beautifully crafted cherry or walnut liquor cabinet was enough to impress visitors with your affluence. These days, if you don’t want to look like a pauper, you have to take it a step further.

[Elias Bakken] and his uncle [Mike Moulton] have decided to take liquor cabinets into the 21st century with a semi-automatic liquor cabinet called Latskap. The project is still in progress, and in the prototyping stage, but their build log on Hackaday.io is showing a lot of potential. It shouldn’t be long before they have a fully functional prototype finished.

Latskap has a few primary functions: the first is that it automatically opens when someone approaches it. Then the thirsty guest can use the touchscreen to choose the drink they’d like from the menu. The bottles inside the cabinet are resting on NeoPixels, and the system lights up the liquor and mixer bottles needed for that drink. Finally, a scale at the front of the cabinet weighs the glass as ingredients are poured, and tells the parched patron when they’ve poured the correct amount for their drink.

We’ve seen liquor dispensers in the past that are designed to mix a cocktail all on their own, but the Latskap takes an interesting new approach. The main benefit of this design is that the number of bottles is limited only by how much room is available. There are no complex pumping systems necessary. We’re definitely looking forward to seeing the finished product!

Filed under: Beer Hacks

Lasering Axonometric Fonts

ศุกร์, 08/18/2017 - 21:01

I am something of an Inkscape fan. If you’re not familiar with the application, it’s like an Open Source version of Adobe Illustrator. Back when I was a production artist I’d been an Illustrator master ninja but it’s been four years and my skills are rusty. Plus, Inkscape is just enough different in terms of menus and capabilities that I had a hard time adapting.

So I created some wooden lettering with the help of Inkscape and a laser cutter, and I’m going to show you how I did it. If you’re interested in following along with this project, you can find it on Hackaday.io.

While playing around with Inkscape, I noticed you can create a variety of grids, including axonometric grids. This term refers to the horizon lines in an orthographic projection. In other words, it helps make things look 3D by providing perspective lines.

Font Play

While a production artist I’d been really into fonts. Especially making my own. I’ve been making typefaces for years, including some unforgivably ’90s grudge fonts that thankfully never made it into the world. Fonts are mostly just vector sets dropped into a database with tracking and kerning data embedded alongside.

I’ve been watching videos of Jimmy Di Resta cutting channel lettering on a bandsaw — he does a million sign projects — so, when I saw that axonometric grid, I got the idea of making a 3D-looking set of letters that could be cut out on a laser cutter and made into a sign. Maybe try 1/8″ plywood, with the different facets being painted different colors to reinforce the perspective.

To begin with, however, I had to create the letters. I wanted to start with an easy project and just use blocky shapes to form the various parts of each letter, rather than create sexy bezier curves. I started drawing different kinds of letters before settling on a tall, slender, blockish shape. I didn’t do the entire alphabet, just enough letters to get a feel for it.

The Third Dimension Illusion

The next step was to create the perspective effect with the help of the axonometric grid. Each point on the grid consists of two diagonals meeting a vertical. Remember the vanishing point in art class? Same thing. You can play with the angles but they all end up working pretty much the same way.

The sides of each shape are easy to create. All you have to do is create a duplicate of the letter in question, drop it to the bottom, and then select “Path > Difference” to cut out the parts that are covered up by the main letter. You will still need to draw in triangular shapes that connect the front and back — you can see them in the image above.

Once you get a sense of your design you can free-hand the side panels pretty easily if you have “snap to grid” turned on.

While I was at it I drew smaller inset letters (marked in blue) that will help give my sign a little more visual interest. Remember, each of those smaller side pieces is going to be its own laser-cut part. I have them color-coded to keep them straight in my head, but ultimately they’ll be spray-painted another color.

Cosmetic Cornering

I also want to draw lines for the corners, purely for cosmetic purposes — they help create the 3D effect. You can see them in the design, marked with fat yellow lines. The real lines won’t be that bold, I just kept them that way during the design process so I wouldn’t lose track of them.

So, having created my sign, it was time to laser it out. I sized it for a 24″x12″ sheet of 1/8″ pine, and I bought a second sheet upon which to glue the letters as they come out of the cutter and are painted. The lasering went off without a hitch, with 100% speed and 100% power ensuring the design was complete in less than 8 minutes. The only thing that went wrong is that I failed to ensure the lettering was centered, so I had a harder time aligning it on the board. The diagonal lines marking the corners went through at 1% power and 100% speed.

I’m really happy how the effect turned out — Now I want to make signs for my house, my friends’ houses, random people on the street! It’s pretty easy and you can do it yourself. Having all of these signs around the house might not be for everyone, but what hackerspace, makerspace, or office space isn’t begging for some colorful signage to spice up the decor?  Grab some friends and start designing!

Filed under: Featured, laser hacks, Skills

Fool Giants with Novelty-Sized Gold Bricks

ศุกร์, 08/18/2017 - 18:00

If you ever wondered how to make a giant-sized gold bar out of sheets of pink household insulation, well, there is a video showing you the steps. YouTube workshop guru [Jimmy DiResta] built oversized prop gold bricks out of foam. He cut sheets of 1.5″ Owens Corning foam insulation on his Saw Stop, making angled edges onto each piece so they could fit together in the trapezoidal ingot shape we know and love.

The pieces were put together with Great Stuff insulating foam sealant, the sort of spray foam used for filling up gaps in your house’s insulation, but here serving as glue.  [Jimmy] created lettering by lasering out the shapes in what appears to be cardboard, then gluing the letters in place, using the leftover material from the laser cut to place the letters in neat rows. He then sanded down the edges, priming and painting the bars with gold paint–but there were too many imperfections visible so he re-sanded and repainted.

We have been inundated in foam projects recently, like this ultralight built out of foam insulation and a foam cutter built with a 9V battery.

Filed under: misc hacks

Catch the Eclipse with a Wearable Pinhole Camera

ศุกร์, 08/18/2017 - 15:00

You say you didn’t have enough warning to order eclipse glasses, and now they’re too expensive to buy? Or maybe you did order some but they ended up being those retina-combusting knock-offs, and now you’ve got nothing to protect you during the partial phase of Monday’s eclipse? Don’t dump a ton of money on unobtainium glasses — just stick your head in a cardboard box.

You may end up looking like a Box Troll with the aptly named [audreyobscura]’s box on your head, but it really is a safe and effective way of watching the eclipse, or for gazing at our star anytime for that matter. It’s nothing more than a large pinhole camera, with a tiny hole in a scrap of aluminum soda can acting as an aperture. The pinhole in one end of a box casts a perfect image of the sun on a paper screen at the other end of the box. A hole for your head with a proper gasket around your neck — maybe the neck of an old T-shirt would be a bit more comfortable and light tight? — and you’re ready for the show. The bigger the box, the bigger (and dimmer) the image will be, so you’ll want to cruise the local home center for long boxes. Because walking around with a water heater box on your head is totally cool.

Really, though, Hackaday readers can’t say they didn’t know this was coming. We started covering this in January, we’ve got hundreds of eclipse meetups across the country, and we’ve even covered some citizen science opportunities you can partake in on Eclipse Day. If you don’t have your head in a box, that is.

Thanks to [Roger Guess] for the idea on this one.

Filed under: misc hacks, wearable hacks

Power Planer Brought Back To Life

ศุกร์, 08/18/2017 - 12:00

Having the right tool for the right job is not always possible, but it’s an ideal that’s nice to try to live up to. The problem is that a lot of the time, the right tool is often very expensive. We have found lots of ways around this, though, from building our own CNC machines to finding new ways to electroplate metal. Sometimes, though, the right tool for the job doesn’t have to be improvised or built from scratch, it just falls in your lap.

Admittedly, [Sam]’s power planer didn’t literally fall into his lap, but he did pull this neglected tool from the garbage. With no idea what was wrong with it, [Sam] let it sit on the shelf for years until he finally needed it. Assuming there was a major problem with the tool, he set about replacing the blades and bearings only to find that the likely culprit behind why the planer was thrown away in the first place was a faulty switch. This was likely a deal and circuit-breaker for someone who would use it all day, but not so for someone who only needs it for occasional use.

While some might not consider this a “hack”, it is at least a reminder that one man’s trash is another man’s treasure, especially if that trash only needs new bearings and a switch. There are two lessons here: first, that tools aren’t usually beyond repair, and that it’s possible to find all kinds of tools in the dumpster from people who don’t heed this advice.

Filed under: tool hacks

New Method for Measuring Lots of Resistors Using Very Few Wires

ศุกร์, 08/18/2017 - 09:00

[Daqq] is back at it again with the linear algebra, and he’s now come up with a method for determining the resistance of lots of resistors using little of wires and loads of math.

Like any reasonable person, [daqq] decided it would be fun to “solve one of those nasty [electrical engineering] puzzles/exercises where you start out with a horrible mess of wires and resistors and you are supposed to calculate the resistance between two nodes.” You know, just an average Saturday night. At the time, he was also fascinated by Charlieplexing – an awesome technique that either allows one to control multiple polarized components, such as LEDs, simply by connecting them in a specific way. After toying with the idea for a while, [daqq] found that using just Charlieplexing would be“a horrible mess” but he didn’t stop there. Drawing inspiration from Charlieplexing, he came up with the idea to connect things in such a way that every node is connected by one connection to every other node – a complete graph from a topological view point (this makes so much more sense visually). From here, he was able to set pins to HIGH, LOW, or INPUT and gather all the data needed to solve his linear system of equations.

Now, there is a balance to everything, and while this system can determine the resistance of .5*N(N-1) resistors using just N wires, it also a memory and computation hungry method. Oh well, can’t have it all. But, while it’s computationally hungry, [daqq] got it working on an ATMega32, so it’s not an unmanageable feat. And, let’s not forget to mention [daqq’s] wonderful writing. Even if you don’t know linear algebra (or would rather forget), it’s a good read from a theory perspective. So good, in fact, that [daqq] is getting published in Circuit Cellar!

We love to see theory in the hacker world, so keep it coming! But, while we wait (wink wink), there’s always time to review the basic Hacker Calculus and check out our past math-related articles.

Filed under: hardware

Crowdsourcing The Study Of An Eclipse’s Effect On Radio Propagation

ศุกร์, 08/18/2017 - 06:01

If you are an American, you’ll probably now find yourself in one of three camps. People who are going to see the upcoming solar eclipse that will traverse your continent, people who aren’t going to see the eclipse, and people who wish everyone would just stop going on incessantly about the damn eclipse.

Whichever of those groups you are in though, there is an interesting project that you can be a part of, an effort from the University of Massachusetts Boston to crowdsource scientific observation of the effect a solar eclipse will have on the upper atmosphere, and in particular upon the propagation of low-frequency radio waves. To do this they have been encouraging participants to build their own simple receiver and antenna, and make a series of recordings of the WWVB time signal station before, during, and after the eclipse traverse.

This is an interesting and unusual take upon participation in the eclipse, and has the potential to advance the understanding of atmospheric science. It would be fascinating to also look at the effect of the eclipse on WSPR contacts, though obviously those occur in amateur bands at higher frequencies.

If you are an EclipseMob participant, we’d love to hear from you in the comments. Does your receiver perform well?

Thanks [Douglas] for the tip.

Filed under: news, radio hacks

Wearable Superconductors

ศุกร์, 08/18/2017 - 03:01

What do you do with a discarded bit of superconducting wire? If you’re [Patrick Adair], you turn it into a ring.

Superconducting wire has been around for decades now. Typically it is a thick wire made up of strands of titanium and niobium encased in copper. Used sections of this wire show up on the open market from time to time. [Patrick] got ahold of some, and with his buddies at the waterjet channel, they cut it into slices. It was then over to the lathe to shape the ring.

Once the basic shape was created, [Patrick] placed the ring in ferric chloride solution — yes the same stuff we use to etch PC boards. The ferric chloride etched away just a bit of the copper, making the titanium niobium sections stand out. A trip through the rock tumbler put the final finish on the ring. [Patrick] left the ring in bare metal, though we would probably add an epoxy or similar coating to keep the copper from oxidizing.

[Patrick] is selling these rings on his website, though at $700 each, they’re not cheap. Time to hit up our the auction sites and find some superconducting wire sections of our own!

If you’re looking to make rings out of more accessible objects, check out this ring made from colored pencils, or this one made from phone wire.

Filed under: wearable hacks

Hackaday Prize Entry: InspectorBot Aims to Look Underneath

ศุกร์, 08/18/2017 - 01:31

Why bother crawling into that tiny sewer tunnel and getting coated in Cthulhu knows what — not to mention possibly getting stuck — when you can roll a robot in there instead? That’s what InspectorBot does. It’s [Dennis]’ entry for The Hackaday Prize and a finalist for our Best Product competition.

InspectorBot is a low-profile rover designed to check out the dark recesses of sewers, crawlspaces, and other icky places where humans either won’t fit or don’t want to go. Armed with a Raspberry Pi computer, it sports a high-definition camera pointed up and a regular webcam pointing forward for navigation. It uses point-to-point WiFi for communication and rocks all-wheel drive controlled by a pair of L293D motor drivers.

This seems like fertile ground for us. Pipe-crawlers, chimney-climbers, crawlspace-slitherers all sound like they’d be helpful, particularly in conjunction with some kind of computer vision that allowed the robot to notice problems even when the operator does not. Right now, [Dennis] has the chassis rolling and most of the current work is focused on software. Both cameras are now working, allowing the InspectorBot to send forward-looking and upward-looking video back to the operator at the same time. This, alone, is a great advancement of the current crop of Raspberry Pi rovers and adds a lot of functionality to an easy-to-build platform.

The HackadayPrize2017 is Sponsored by:
Filed under: The Hackaday Prize