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ถูกปรับปรุง 58 min 31 sec ก่อน

VR Mech’s Missing Link: The Phone in Your Pocket

2 hours 36 minก่อน

In the process of making a homemade Mech Combat game that features robot-like piloted tanks capable of turning the cockpit independent of the direction of movement, [Florian] realized that while the concept was intuitive to humans, implementing it in a VR game had challenges. In short, when the body perceives movement but doesn’t feel the expected acceleration and momentum, motion sickness can result. A cockpit view that changes independently of forward motion exacerbates the issue.

To address this, [Florian] wanted to use a swivel chair to represent turning the Mech’s “hips”. This would control direction of travel and help provide important physical feedback. He was considering a hardware encoder for the chair when he realized he already had one in his pocket: his iPhone.

By making an HTML page that accesses the smartphone’s Orientation API, no app install was needed to send the phone’s orientation to his game via a WebSocket in Unity. He physically swivels his chair to steer and is free to look around using the VR headset, separate from the direction of travel. Want to try it for yourself? Get it from [Florian]’s GitHub repository.

A video is embedded below, but if you’re interested in details be sure to also check out [Florian]’s summary of insights and methods for avoiding motion sickness in a VR Mech cockpit.

This project incorporates a physical element into the VR environment, but there’s neat work being done in the other direction as well; how about spicing up your stationary bike with a VR headset and Google street view data?

Filed under: iphone hacks, Virtual Reality

Get Up Close to your Soldering with a Pi Zero Microscope

5 hours 36 minก่อน

Do your Mark 1 Eyeballs no longer hold their own when it comes to fine work close up? Soldering can be a literal pain under such conditions, and even for the Elf-eyed among us, dealing with pads at a 0.4-mm pitch is probably best tackled with a little optical assistance. When the times comes for a little help, consider building a soldering microscope from a Pi Zero and a few bits and bobs from around the shop.

Affordable commercial soldering scopes aren’t terribly hard to come by, but [magkopian] decided to roll his own by taking advantage of the streaming capabilities of the Raspberry Pi platform, not to mention its affordability. This is a really simple hack — nothing is 3D-printed or custom milled. The stage base is a simple aluminum project box for heat resistance and extra weight, and the arm is a cheap plastic dial caliper. The PiCam is mounted to the sliding jaw of the caliper on a scrap of plastic ruler. The lens assembly of the camera needs to be hacked a little to change the focal length to work within 10 centimeters or so; alternatively, you could splurge and get a camera module with an adjustable lens. The Pi is set up for streaming, and your work area is presented in glorious, lag-free HDMI video.

Is [magkopian]’s scope going to give you the depth perception of a stereo microscope? Of course not. But for most jobs, it’ll probably be enough, and the fact that it can be built on the cheap makes it a great hack in our book.

Filed under: Raspberry Pi, tool hacks

Old Part Day: Voltage Controlled Filters

8 hours 37 minก่อน

For thirty years, the classic synths of the late 70s and early 80s could not be reproduced. Part of the reason for this is market forces — the synth heads of the 80s didn’t want last year’s gear. The other part for the impossibility to build new versions of these synths was the lack of parts. Synths such as the Prophet 5, Fairlight CMI, and Korg Mono/Poly relied on voltage controlled filter ICs — the SSM2044 — that you can’t buy new anymore. If you can source a used one, be prepared to pay $30. New old stock costs about $100.

Now, these chips are being remade. A new hardware revision for this voltage controlled filter has been taped out by the original hardware designer, and these chips are being produced in huge quantities. Instead of $100 for a new old stock chip, this chip will cost about $1.60 in 1000 unit quantities.

The list of synths and music boxes sporting an SSM2044 reads like a Who’s Who of classic electronic music machines. E-Mu Drumulators, Korg polyphonic synths, Crumars, and even a Doepfer module use this chip in the filter section. The new chip — the SSI2144 — supposedly provides the same classic tone but adds a few improvements such as improved pin layouts, an SSOP package, and more consistent operation from device to device.

This news follows the somewhat recent trend of chip fabs digging into classic analog designs of the 70s, realizing the chips are being sold for big bucks on eBay, and releasing it makes sense to spin up a new production line. Last year, the Curtis CEM3340 voltage controlled oscillator was rereleased, giving the Oberheim OB, Roland SH and Jupiter, and the Memory Moog a new lease on life. These chips aren’t only meant to repair broken, vintage equipment; there are a few builders out there who are making new devices with these rereleased classic synths.


Filed under: hardware, musical hacks

Look at me with your Special Animatronic Eyes

11 hours 38 minก่อน

Animatronics for movies is often about making something that works and is reliable in the short term. It doesn’t have to be pretty, it doesn’t have to last forever. [Corporate Sellout]  shows us the minimalist approach to building animatronics with this pair of special eyes.  These eyes move in both the pan and tilt. Usually, that means a gimbal style mount. Not in this case. The mechanical assembly consists of with popsicle sticks, ping-pong balls, film canisters and dental floss.

The frame for the eyes is made of simple popsicle sticks hot glued together. The eyes themselves are simple ping-pong balls. Arduino powered servos control the movement. The servos are connected to dental floss in a cable arrangement known as a pull-pull system. As each servo moves, one side of the arm pulls on a cable, while the other provides enough slack for the ping-pong ball to move.

Mounting the ping-pong balls is the genius part of this build. They simply sit in the open end of a couple of film canisters. the tension from the dental floss holds everything together. We’re sure it was a finicky setup to build, but once working, it’s reliable. Only a glue joint failure or stretch in the dental floss could cause issues.

There are plenty of approaches to Animatronic eyes. Check out the eyes in this Stargate Horus helmet, which just won our Sci-Fi contest. More recently we saw Gawkerbot, which uses a CD-ROM drive to provide motion for a creepy robot’s eyes.

Filed under: classic hacks, robots hacks

Error: LP0 On

14 hours 38 minก่อน

You don’t need fancy ICs and DACs to build a sound card for a PC. As [serdef]’s build over on hackaday.io shows, all you really need is a bunch of resistors. [serdef] built a clone of a sound card released for PC in the 80s, but with a few improvements. This mess of resistors features the best 8-bit sound you can get with a low-pass filter, volume divider, and a handy DB-25 connector.

The design of this LPT0 sound card is pretty much the same as when it was introduced to the world as the Covox Speech Thing. This ‘sound card’ was designed to clip onto the parallel port of a computer and send the 8-bit I/O of this port through a resistor ladder. Plug a pair of speakers into this thing, and you have a sound card that is completely made out of resistors. It was cheap, and in the demoscene it was popular.

There are a lot of amazing demos out there using this resistor DAC thing, and [serdef] has videos of his project playing a lot of them. You can check that out below.

Filed under: classic hacks

Heavy Metal Detectors

17 hours 38 minก่อน

Helsinki has a strong underground Heavy Metal scene, so what better way to show it off than to have listeners literally unearth the local sounds themselves with converted metal detectors that play, naturally, Metal? [Steve Maher] built these modified detectors and handed them to a bunch of participants who went on exploratory walks around the city. The tracks from local bands changed as the user moved from one concealed metallic object to the other to create the experience of discovering the hidden soundscape of the land. 

Because there was no writeup on the hardware, we contacted [Steve] ourselves, and here is what we learned.  [Luis Alejandro Olarte] helped out on the build that uses a Teensy 3.2 with an audio shield to play tracks from an SD card. The beeps that would normally help you find metallic objects are fed to the Teensy and control the volume of the output audio. The Teensy then loops through a 45 minute track that is only audible when metal is detected. This allows the audience to establish a connection between the metal as well as the music.

The video has [Steve Maher] talking about the concept and some of the walks organised under the project as part of Live Herring.

We think this is a great idea and can think of other variations on the theme. Using color sensors to play tracks and sounds that allow individuals with colour blindness or complete ocular disability to experience the hues in an auditory way? Red with loud music and sky-blue with the calm sound of a cool breeze. Adding a bit of haptic feedback could take this idea in so many directions.

If you’d rather DIY your own than modify one off the shelf, here’s an article on building your own metal detector.

Filed under: Microcontrollers, musical hacks

Hackaday Prize Entry: Brightenmacher

19 hours 7 minก่อน

We have all at some point have made a flashlight. It used to be a staple of childhood electronics, the screw-in bulb in a holder, and a cycle lamp battery. If you were a particularly accomplished youthful hacker you might even have fitted a proper switch, otherwise, you probably made do with a bent paperclip and a drawing pin.

So you might think that flashlights offer no challenges, after all, how many ways can you connect a bulb or an LED to a battery? [Peter Fröhlich] though has a project that should put those thoughts out of your mind. It uses a power LED driven by a TI TPS61165 boost driver, with an ATTiny44 microcontroller providing control, battery sensing, and button interface. The result is a dimmable flashlight in a 3D printed case housing both control circuitry and a single 18650 cell which he sourced from a dead laptop. Suddenly that bent paperclip doesn’t cut it anymore.

The result is a flashlight that is the equal of any commercial offering, and quite possibly better than most of them. You can build one yourself, given that he’s published the physical files necessary, but probably because this is a work in progress there are as yet no software files.

We’ve featured a lot of flashlights over the years, but it’s fair to say they usually tend towards the more powerful. Back in 2015 we published a round-up of flashlight projects if it’s a subject that captures your interest.

The HackadayPrize2017 is Sponsored by:


Filed under: led hacks, The Hackaday Prize

Ask Hackaday: What About the Diffusers?

20 hours 36 minก่อน

Blinky LED projects: we just can’t get enough of them. But anyone who’s stared a WS2812 straight in the face knows that the secret sauce that takes a good LED project and makes it great is the diffuser. Without a diffuser, colors don’t blend and LEDs are just tiny, blinding points of light. The ideal diffuser scrambles the photons around and spreads them out between LED and your eye, so that you can’t tell exactly where they originated.

We’re going to try to pay the diffuser its due, and hopefully you’ll get some inspiration for your next project from scrolling through what we found. But this is an “Ask Hacakday”, so here’s the question up front: what awesome LED diffusion tricks are we missing, what’s your favorite, and why?

Diffusive Materials, Blending Colors

Look closely enough at an RGB LED and you’ll see three individual LED chips, not surprisingly in red, green, and blue. We all know this, and yet it’s still surprising how badly blended the colors can be, even from an LED unit like the WS2812, where the three diodes are ridiculously tiny and less than a millimeter apart. Somehow, even at desk-distance, you still get the feeling that you’re looking at a red LED and a blue LED instead of a blended magenta light source.

One approach is to use a diffusive material that has a rough enough surface that it scatters the light that passes through it. Diffusive materials include something “traditional” like frosted glass or acrylic, as seen in [Mike Szczys]’s 1 Pixel Pacman demo video or this classy linear RGB clock. Something like 50% transparent acrylic seems to be just about right. You can get a similar effect by sanding or tumbling a clear LED.

Then there are “oddball” diffusers. A drop of hot glue works pretty well, because it’s rarely crystal clear. Stranger still is polyester pillow stuffing. Lately, I’ve been experimenting with re-melting candles and entombing LEDs in paraffin wax — around 1 cm depth yields very uniform colors. I’ve also seen holes drilled in wooden cases, filled with epoxy, and sanded down.

You could always 3D print the case in a translucent material, so that the case is the diffuser. Or you can just hold up a sheet of paper or a cutout from a milk jug. These low-tech options work surprisingly well.

The main variables with diffusive materials is how transmissive the material is and how far away from the LED it’s located. Thicker, less transmissive materials tend to blur better but darken the LED more — sometimes a good thing. Locating the diffuser further away tends to mix colors better, but also blurs the points of light out, and can muddy up the image. Again, sometimes you want this effect, like in this wall panel, and sometimes you don’t, like in [Mike]’s Pacman. But the distance to the diffuser can be critical. Test it out well before designing the case.

Reflective Cavities, Shaping Light

Reflective cavities serve the same purpose as translucent material, but can be lighter weight if more difficult to construct. You can either add a diffuser sheet to the front of the cavity or not, as you wish. Both can be really nice effects. For instance, “Ecstatic Epiphany” by [Micah Elizabeth Scott] uses folded borders that bounce the LEDs off of a light-colored surface, and spread it around a little bit, to achieve both color mixing and some shaping. It works fine without any front cover.

Colossus” uses white foam-core dividers to make many individual reflective cavities, covered with two layers of white bed sheet as a front-surface diffuser. Within each cell, the colors are discrete and well mixed, for the perfect big-pixel effect. You could also use straws, toilet-paper tubes, or even soda bottles.

Photographer’s light boxes are also essentially diffuser cavities. We’ve shot many of our closeups in one that’s made of “vellum” art paper surrounding a wooden frame, but we recently upgraded to IKEA Trofast with optional LED lighting for nocturnal photo sessions. Most of the light coming through the translucent plastic ends up bouncing around inside, leaving very soft shadows and even illumination. It works better when driven by daylight. If you want to take this idea to the extreme, check out [Doog]’s model shooting rig. Note the clever use of underlit diffusive acrylic.

Nothing is stopping you from making interesting shapes out of the reflective cavities. Triangle-shaped reflective cells give [Micah Scott]’s “Triangle Attractor” and [Becky Stern]’s WiFi wall display their style. If triangles aren’t your thing, you can 3D-print the cavities in whatever shape you need, like these 16-segment displays.

Designing the diffusive cavity just right is an art more than a science. Generally speaking, the more reflective the walls, and the more volume they enclose, the better the color mixing is going to be. It’s definitely worth your time to experiment around with indirect illumination, where the light bounces first before leaving the box. Combining cavities with diffusive material front panels can yield some very subtle effects.

The Ask

Pshwew! That was a whirlwind tour of diffusing options, divided arbitrarily into categories of diffusive materials and cavities, with overlap. What did we miss? What’s your favorite LED diffusive effect?

Filed under: Ask Hackaday, led hacks, Skills

Around the Globe on World Create Day

อังคาร, 04/25/2017 - 23:01

Last weekend was great for science and technology. While thousands of people took to the streets to protest anti-intellectualism, a few members of the Hackaday community dug their heels in, turned on the soldering iron, and actually did something about it. This was World Create Day, a community effort to come together and build something that matters. What did these people build? So much awesome stuff.

The Nest I/O in Karachi, Pakistan

The folks at The Nest I/O hackerspace in Karachi, Pakistan had a rather large meetup for World Create Day featuring the finest in laser cut, googly-eyed fighting robots. [Nasir Aziz] hosted a meetup at his favorite hackerspace for people to get together, discuss, and build something for the Hackaday Prize.

The highlight of the meetup was a discussion from EjaadTech, an industrial design firm that graduated from The Nest I/O accelerator. Among the projects invented during World Create Day were a ‘shopping helper drone’ and miniature fighting robots. Useful projects on one hand, awesome projects on the other, just like we like it.

MakerBay in Hong Kong A solar oven found at MakerBay

MakerBay is a hackerspace located smack in the middle of Hong Kong. Like most hackerspaces, finding a place was a problem, but the folks at MakerBay found something spectacular. They’re zoned industrial, and only a five-minute walk from a train station.

There are quite a few projects sitting around MakerBay including a solar oven that would be pretty dangerous if it were outdoors on a sunny day. Also on deck are prototypes of small sailing vessels with a flexible hull designed to track and contain oil spills.  Highlights of World Create Day include upcycled wood construction and a spontaneous piano interlude. I’m surprised I haven’t seen more hackerspaces with a piano; they’re effectively free if you have a truck and a place to store it.

BlenderLab in Lille

While the World Create Day event at the BlenderLab hackerspace in Lille, France didn’t set out to change the world with a project, they did manage to come up with a really neat digital hourglass. The body of this hourglass is made out of laser cut plywood, with the display made out of two LED matrices oriented at a 45-degree angle.

Hackaday NYC

[Zach Freedman] reveals his devious plotWhile World Create Day is a challenge for hackerspaces around the globe to come together and create something that solves a problem, that doesn’t mean there aren’t slightly more official events around the globe. Hackaday set up our own events in New York City, LA, and San Francisco.  The New York event was great thanks to our lovely East coast community manager [Shayna] and our hosts at Fat Cat Fab Lab.

[Zach Freedman], one of the regulars at our NYC meetups has an ulterior motive for getting the Fat Cat Fab Lab members to contribute their ideas to the Hackaday Prize: winning the Hackaday Prize would result in donating the winnings to the Fab Lab. It’s a brilliant and devious plot we very much recommend.

Tell us about your World Create Day

There were many more events going on around the globe last weekend, and we want to hear about how your World Create Day went. We’ll be covering more of the events of last weekend in the coming days, so make sure to add your pictures, stories, and links to the projects you started on your World Create Day event page on Hackaday.io. Event organizers are going to get some super awesome swag for making that effort.

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

An Analog Charge Pump Fabrication-Time Attack Compromises A Processor

อังคาร, 04/25/2017 - 22:00

We will all be used to malicious software, computers and operating systems compromised by viruses, worms, or Trojans. It has become a fact of life, and a whole industry of virus checking software exists to help users defend against it.

Underlying our concerns about malicious software is an assumption that the hardware is inviolate, the computer itself can not be inherently compromised. It’s a false one though, as it is perfectly possible for a processor or other integrated circuit to have a malicious function included in its fabrication. You might think that such functions would not be included by a reputable chip manufacturer, and you’d be right. Unfortunately though because the high cost of chip fabrication means that the semiconductor industry is a web of third-party fabrication houses, there are many opportunities during which extra components can be inserted before the chips are manufactured. University of Michigan researchers have produced a paper on the subject (PDF) detailing a particularly clever attack on a processor that minimizes the number of components required through clever use of a FET gate in a capacitive charge pump.

On-chip backdoors have to be physically stealthy, difficult to trigger accidentally, and easy to trigger by those in the know. Their designers will find a line that changes logic state rarely, and enact a counter on it such that when they trigger it to change state a certain number of times that would never happen accidentally, the exploit is triggered. In the past these counters have been traditional logic circuitry, an effective approach but one that leaves a significant footprint of extra components on the chip for which space must be found, and which can become obvious when the chip is inspected through a microscope.

The University of Michigan backdoor is not a counter but an analog charge pump. Every time its input is toggled, a small amount of charge is stored on the capacitor formed by the gate of a transistor, and eventually its voltage reaches a logic level such that an attack circuit can be triggered. They attached it to the divide-by-zero flag line of an OR1200 open-source processor, from which they could easily trigger it by repeatedly dividing by zero. The beauty of this circuit is both that it uses very few components so can hide more easily, and that the charge leaks away with time so it can not persist in a state likely to be accidentally triggered.

The best hardware hacks are those that are simple, novel, and push a device into doing something it would not otherwise have done. This one has all that, for which we take our hats off to the Michigan team.

If this subject interests you, you might like to take a look at a previous Hackaday Prize finalist: ChipWhisperer.

[Thanks to our colleague Jack via Wired]

Filed under: security hacks

Different Differentials & The Pitfalls of the Easy Swap

อังคาร, 04/25/2017 - 21:01

I dig cars, and I do car stuff. I started fairly late in life, though, and I’m only just starting to get into the whole modification thing. Now, as far as automobiles go, you can pretty much do anything you set your mind to – engine swaps, drivetrain conversions, you name it – it’s been done. But such jobs require a high level of fabrication skill, automotive knowledge, and often a fully stocked machine shop to match. Those of us new to the scene tend to start a little bit smaller.

So where does one begin? Well, there’s a huge realm of mods that can be done that are generally referred to as “bolt-ons”. This centers around the idea that the install process of the modification is as simple as following a basic set of instructions to unbolt the old hardware and bolt in the upgraded parts. Those that have tread this ground before me will be chuckling at this point – so rarely is a bolt-on ever just a bolt-on. As follows, the journey of my Mazda’s differential upgrade will bear this out.

The car in question, currently known as the “Junkbox MX-5” until it starts running well enough to earn a real name. It somehow looks passable here, but in person I promise you, it looks awful.

It all started when I bought the car, back in December 2016. I’d just started writing for Hackaday and my humble Daihatsu had, unbeknownst to me, just breathed its last. I’d recently come to the realisation that I wasn’t getting any younger, and despite being obsessed with cars, I’d never actually owned a sports car or driven one in anger. It was time to change.

After realising all my favourite JDM metal was outside a budget I was comfortable spending, I settled on an automotive classic – I’d have a Mazda MX-5, known to the Americans as the Miata. It’s a Japanese take on the old British sportscar – a convertible roadster with an engine in the front, driving the rear wheels. I wanted the cheapest one I could find, and well – safe to say, I got it.

When I rolled up to buy the thing, it looked okay – some shabby paintwork, sure, but it drove great! It was a 1990 with the smaller 1.6 litre engine, and no performance parts to speak of, but I wanted a project anyway. I happily parted with $3000 and all was well, for about fifteen minutes. You see, on the way home, a terrible, awful noise began to emanate from the car’s drivetrain. My heart sank at rather a high rate of knots.

After limping home praying the thing wasn’t about to completely explode, I sprinted to the Internet for help.

“Weird deceleration noise”
“Scraping mx-5 deceleration”
“Miata drivetrain shuffling noise”

To my relief, thousands of people had exactly the same problem I did – a strange shuffling or scraping noise on deceleration in gear. To my exasperation, it wasn’t clear what the problem was – was it the differential, the gearbox – an exhaust heat shield? Eventually, I took a trip to a local MX-5 expert who indicated it was likely the gearbox or differential, but despite the noise it would probably be okay for another 50,000 km or so until I could get it fixed.

Now slightly more comfortable, I resolved to put up with the noise while I got on with real life. In the mean time, the car rewarded me with more trouble, like overheating – eventually solved by a radiator replacement you can watch in the video below.

I was very much getting my money’s worth out of this car, but I wasn’t worried. I’d bought this car expecting to upgrade virtually everything on it anyway, so I wasn’t too cut up about the worn out parts. After much research, I had decided that I wanted to upgrade to a limited-slip differential (LSD), which allows better torque distribution between the rear wheels for better grip and handling. Plus it helps you do mad skids. I settled on a 4.1 ratio unit from the more recent 1.8 litre cars, sourced from a wrecker a state over.

The Torsen LSD from a 1.8 litre MX-5, along with tailshaft & halfshafts with hubs attached. Apparently removing the halfshafts from the hubs is insanely difficult so I’m thankful the wrecker left them attached.

Now, I initially wasn’t too worried about the swap. The 1.8 litre LSD in itself isn’t a direct swap into a 1.6 litre car. However, if sourced with the tailshaft and halfshafts from a 1.8 litre car as well, everything should just bolt up. Sounds easy, right?

Well, that’s where the trouble starts. I’ve only been doing bigger mechanical jobs like this for a few months, but I was confident after reading a few tutorials that I could complete the job in just a few hours. But the tutorials I read assume a certain level of experience that I quickly learned I didn’t have.

First problem – tools! I’d happened across a great trolley jack and sourced some jackstands so I could get under the car. After getting everything set up, I slid under the car and prepared to start unbolting the differential mounts. Armed with a 3/8 inch ratchet I got in a cheap $50 toolkit, I was quickly disappointed. Drivetrain and suspension components are generally held on with very large fasteners, done up to a very high torque. We rounded off the 3/8 socket extension in the first five minutes, and called it a day while we waited for the hardware store to open.

This socket set was integral to getting the job done. A good set of tools will make your wrenching activities much more pleasurable.

The next day, I was back, armed with a tough new socket set. To say this transformed my experience is a total understatement. Suddenly, with a 300 mm extension and the 1/2 inch drive breaker bar, the nuts holding on the differential were no match for my raw strength. Instantly what felt like an impossible task seemed again to be a quick, one-day job. Until the next pitfall.

Things on cars get stuck a lot. Put a big bolt through a few parts, wang it up to 150 foot-pounds, and blast it with dirt and water for 27 years. Remove the bolt, and you might find it’s all still stuck together. As you’re trying to free things up, the initial instinct might be to reach for a hammer. But it’s not so easy –  sometimes it’s not obvious if you’re actually hitting the right thing. Other times, you’re on the ball, smack the part free – only to realise you’ve just put your screwdriver through a brake line. It often takes finesse, a cup of tea, and a quick question to the relevant forum or Facebook group to identify where one should place one’s hammer, and how hard one should swing it. On this job, there was confusion about a bushing that was holding the old differential on to the power plant frame – thankfully, the fine people of the Mazda MX-5 of Australia group confirmed I could bash away with impunity, and I did so.

A stubborn bushing. Hammer away, they said, and hammer I did.

Next problem was bolts. Despite ordering “everything” I needed to fit the diff to a 1.6 litre car, the wrecker had only supplied two nuts to go with the four bolts that attach the tailshaft to the differential. I suspect they might have been lost in transit, as everything was shipped loose. I wasn’t able to follow my initial plan of reusing the old nuts either – they were a smaller size. In the end, a last minute dash to the parts store netted me some slightly larger nuts that fit. It might sound strange to say that bolts are a problem, but you might be surprised. Automotive manufacturers generally use a higher grade of bolts than is typically available at the local hardware store, and in a much wider variety of thread pitches. Replacements are accessible at a specialty fastener distributor, but these all close at 5:00 PM and don’t open on weekends – cold comfort to the shadetree mechanic with a full-time job. I was thankfully saved by the auto parts store which did have the correct pitch nuts I needed on a Saturday, albeit at $7 for a pack of three. It was a better option than driving out to the wrecking yard to yank a single bolt off the nearest Mazda, though. With that solved, I felt confident I could finish the car that night.

The halfshaft, impudently refusing to seat fully in the differential. The green section should be fully flush up against the differential housing & seal.

I moved on to the next job – fitting the new halfshafts to the new differential. To my surprise, they didn’t just slide in. A quick search found that they required a heavy pounding with a stout hammer, so, after much wrestling with the shafts, which still had the hubs attached, I got the left one in. Buoyed by my new success, I was excited, and started immediately on the right, but to no avail. Repeated blows did nothing to force it in to its full depth. I once again begged the forums for insight, who all reported that it was difficult, but more hammering should do the job. At this point though, fatigue was setting in and I decided to finish up with a fresh mind and body in a few days.

Now armed with everything I needed, on the Monday, the work went quickly. A quick strike from the hammer seated the previously immovable half shaft. I didn’t stop to ask why. The differential was bolted up and filled with fluid, the powerplant frame aligned, and the transmission topped up with oil. I was excited – the car was close! All we had to do was refit the rear brakes and take it for a spin. The right side went together in a snap – I was well acquainted with the brakes by this point, having done an upgrade to the later model brakes when I found my car’s rear calipers were both non-functional.

It was dark by this point as we were working on the last wheel. For some reason the brakes just weren’t going together, and we kept fumbling around as we tried to take shortcuts, not wanting to disassemble the caliper any more than necessary to get it back together. Eventually, we realised the problem.

Yes, that brakepad is severely bent. I can only presume that it was due to incorrect fitment during the upgrade, but nonetheless. Not wanting to stop, we found a spare pad with the parts left over from the brake upgrade, and got halfway through putting everything back together until we realised the spare pad was the wrong type and it was all over. My three-hour differential upgrade was now going to bleed into a fourth day.

A good brake pad (top) versus the bent one (bottom). Note the highly irregular wear. The bent pad up against a rule. Colorized for clarity. I’m still not 100% sure how this happens on a single piston caliper.

By this point it was Wednesday, and armed with a new set of rear pads, I once again disassembled both rear brake assemblies and fitted everything up. I lazily adjusted the handbrake as, in several hours of trying, I’ve never been able to get it right despite following the proper instructions. I wasn’t surprised or that bothered when the handbrake largely failed to work.  With the wheels now back on, the car was gently lowered down off its stands, ready to drive.

To say I was nervous was an understatement. While it may be a “bolt-on” job, drivetrain components are more than capable of doing a lot of damage in the event something goes wrong. Reversing out of the driveway went well though, and there were no immediate catastrophic sounds as I drove the car to a friend’s extended driveway for testing. With the engine dialled up to 5,000 rpm, I dropped the clutch and to my delight, the car spun both rear wheels as expected – without flinging rotating metal components all over the place. The drive home further confirmed my success, with the awful scraping sounds now absent from my drivetrain.

I’m pretty darn pleased with the job, and can’t wait to test the car further at an upcoming skidpan day at the nearest racetrack. There’s still a long way to go, and I’m sure this won’t be the last part of the MX-5 to suddenly and unceremoniously fail on me. At the end of the day though, I managed to suffer through a “simple 3-hour bolt-on job”, even if it took me four days – and I’m all the more experienced for it.


Filed under: car hacks

Papa Loves Mamba: Slithering Robot is Reconfigurable

อังคาร, 04/25/2017 - 18:01

It makes sense considering evolution, but nature comes up with lots of different ways to do things. Consider moving. Land animals walk on four feet or two, some jump, and some use peristalsis or otherwise slither. Oddly, though, mother nature never developed the wheel (although the mother-of-pearl moth’s caterpillar will form its entire body into a hoop and roll away from attackers). Human-developed robots which, on the other hand, most often use wheels. Even a tank track has wheels within. [Joesinstructables] latest robot still uses wheels, but it emulates the slithering motion of a snake, He calls it the Lake Erie Mamba.

The most interesting thing about the robot is that it can reconfigure and move in several different modalities. Like the caterpillar, it can even form a wheel like an ouroboros and roll. You can see that at the end of the video, below.

The base configuration slithers and uses 12 segments, each containing a servo motor. [Joe] uses a key fob remote to drive the snake, although it can move by itself, too. The brains are — what else — an Arduino. In some configurations, the snake carries its own brain and power. In others, there’s a scary-looking wiring harness necessary when the snake becomes a wheel because it has no room in that configuration for the extra items.

Real snakes have different ways they move, and so does the Lake Erie Mamba. In the slithering configuration, passive wheels convert a sine or cosine wave motion into linear motion. [Joe] explains the math behind the motion. If you take off the passive wheels, the snake can move like an inch worm. Turning is complicated in this mode since it can only go forward or backward without some changes. The segments can reconfigure to put a drive wheel in play to introduce the desired lateral motion.

Real snakes can combine the two kinds of motion to “sidewind” and the Mamba can do that too. This does require reconfiguration of the segments and driving some segments with a sine wave and others with a cosine wave.

This isn’t the first time we’ve seen the ouroboros trick. If you think robotic snakes couldn’t possibly be useful, think again. Of course the modular robot that captured our hears is Dtto, which claimed the Grand Prize in last year’s Hackaday Prize.

Filed under: Arduino Hacks, robots hacks

Model Sputnik Finds its Voice After Decades of Silence

อังคาร, 04/25/2017 - 15:01

As we approach the 60th anniversary of the human race becoming a spacefaring species, Sputnik nostalgia will no doubt be on the rise. And rightly so — even though Sputnik was remarkably primitive compared to today’s satellites, its 1957 launch was an inflection point in history and a huge achievement for humanity.

The Soviets, understandably proud of their accomplishment, created a series of commemorative models of Earth’s first artificial moon as gifts to other countries. How one came into possession of the Royal Society isn’t clear, but [Fran Blanche] found out about it through a circuitous route detailed in the video below, and undertook to reproduce the original electronics from the model that made the distinctive Sputnik beeps.

The Royal Society’s version of the model no longer works, but luckily it came with a schematic of the solid-state circuit used to emulate the original’s vacuum-tube guts. Intent on building the circuit as close to vintage as possible and armed with a bag of germanium transistors from the 60s, [Fran] worked through the schematic, correcting a few issues here and there, and eventually brought the voice of Sputnik back to life.

If you think we’ve covered Sputnik’s rebirth before, you may be thinking about our article on how some hams rebuilt Sputnik’s guts from a recently uncovered Soviet-era schematic. [Fran]’s project just reproduces the sound of Sputnik — no license required!

Filed under: classic hacks

ESP32’s Freedom Output Lets You Do Anything

อังคาร, 04/25/2017 - 12:00

The ESP32 is Espressif’s new wonder-chip, and one of the most interesting aspects of its development has been the almost entirely open-source development strategy that they’re taking. But the “almost” in almost entirely open is important — there are still some binary blobs in the system, and some of them are exactly where a hacker wouldn’t want them to be. Case in point: the low-level WiFi firmware.

So that’s where [Jeija]’s reverse engineering work steps in. He’s managed to decode enough of a function called ieee80211_freedom_output to craft and send apparently arbitrary WiFi data and management frames, and to monitor them as well.

This ability is insanely useful for a WiFi device. With low-level access like this, one can implement custom protocols for mesh networking, low-bandwidth data transfers, or remove the requirement for handshaking entirely. One can also spam a system with so many fake SSIDs that it crashes, deauth everyone, or generally cause mayhem. Snoop on your neighbors, or build something new and cool: with great power comes great responsibility.

Anyway, we reported on [Jeija]’s long distance hack and the post may have read like it was all about the antenna, but that vastly underestimates the role played by this firmware reverse-engineering hack. Indeed, we’re so stoked about the hack that we thought it was worth reiterating: the ESP32 is now a WiFi hacker’s dream.

Filed under: wireless hacks

Hackaday Prize Entry: MCXY – Mini Laser Cut Aluminum 3D Printer

อังคาร, 04/25/2017 - 09:00

With the easy availability of cheap and 3D printers from the usual Chinese websites, you might think that there could be little room for another home-made 3D printer project. fortunately, the community of 3D printer making enthusiasts doesn’t see it that way.

[Bobricius] has a rather nice 3D printer design in the works that we think you’ll like. It follows the MakerBot/Ultimaker style of construction in that it is a box rather than a gantry, and it is assembled from CNC-cut aluminum for a sturdy and pleasing effect. Whar sets it apart though is its size, at only 190x190x251mm and with an 80x80x80mm print volume, it’s tiny. You might wonder why that could be an asset, but when you consider that he already has a much larger printer it becomes obvious that something small and portable for quick tiny prints could be an asset.

Unusually for a home-made 3D printer, it has no 3D printed parts, instead, it is laser cut throughout. And also unusually all the CAD work was done in EAGLE, better known for PCB work. It’s a work in progress we’re featuring today because it’s a Hackaday Prize entry, but it looks as though the finished item will be something of a little gem.

Homemade 3D printers can be particularly impressive, for example, we’ve shown you this excellent SLA printer.

The HackadayPrize2017 is Sponsored by:
Filed under: 3d Printer hacks, The Hackaday Prize

Steve Evans Passes Away, Leaves an Inspiring Legacy

อังคาร, 04/25/2017 - 06:00

It is with great sadness that Hackaday learns of the passing of Steve Evans. He was one of the creators of Eyedrivomatic, the eye-controlled wheelchair project which was awarded the Grand Prize during the 2015 Hackaday Prize.

News of Steve’s passing was shared by his teammate Cody Barnes in a project update on Monday. For more than a decade Steve had been living with Motor Neurone Disease (MND). He slowly lost the function of his body, but his mind remained intact throughout. We are inspired that despite his struggles he chose to spend his time creating a better world. Above you can see him test-driving an Eyedrivomatic prototype which is the blue 3D printed attachment seen on the arm of his chair.

The Eyedrivomatic is a hardware adapter for electric wheelchairs which bridges the physical controls of the chair with the eye-controlled computer used by people living with ALS/MND and in many other situations. The project is Open Hardware and Open Source Software and the team continues to work on making Eyedriveomatic more widely available by continuing to refine the design for ease of fabrication, and has even begun to sell kits so those who cannot build it themselves still have access.

The team will continue with the Eyedrivomatic project. If you are inspired by Steve’s story, now is a great time to look into helping out. Contact Cody Barnes if you would like to contribute to the project. Love and appreciation for Steve and his family may be left as comments on the project log.

Filed under: news

PogoPlug Hacking: A Step by Step Guide to Owning The Device

อังคาร, 04/25/2017 - 03:00

[Films By Kris Hardware] has started quite an interesting YouTube series on hacking and owning a PogoPlug Mobile v4. While this has been done many times in the past, he gives a great step by step tutorial. The series so far is quite impressive, going into great detail on how to gain root access to the device through serial a serial connection.

PogoPlugs are remote-access devices sporting ARM processor running at 800 MHz, which is supported by the Linux Kernel.  The version in question (PogoPlug Mobile v4) have been re-purposed in the past for things like an inexpensive PBX, an OpenWrt router and even a squeezebox replacement. Even if you don’t have a PogoPlug, this could be a great introduction to hacking any Linux-based consumer device.

So far, we’re at part three of what will be an eight-part series, so there’s going to be more to learn if you follow along. His videos have already covered how to connect via a serial port to the device, how to send commands, set the device up, and stop it calling home. This will enable the budding hacker to make the PogoPlug do their bidding. In this age of the cheap single-board Linux computer, hacking this type of device may be going out of style, but the skills you learn here probably won’t any time soon.

Filed under: hardware, how-to

Behold the Many Builds of World Create Day

อังคาร, 04/25/2017 - 01:31

World Create Day was huge this year. Over 70 different groups on six continents got together on Saturday to work on projects as a global Hackaday community.

LearnOBots Labs in Islamabad, Pakistan

Perhaps the best documented World Create Day so far comes from our friends in Pakistan. LearnOBots hosted a day-long extravaganza of projects on everything from home automation, to wearable computing.

[Haziq] and [Rafay] didn’t just build an IoT lighting project together, they took the time to present their work in this excellent demo video. The build connects Arduino, a Bluetooth module, and a relay to drive the lightbulbs all controlled by an app they built with MIT app inventor to help a friend who is stuck on bed rest.

Browse through the event logs LearnOBots has posted and see a lot more of what went on. This image shows work on wearable interfaces. Fabric markers are used to draw out interesting designs which are then given interactivity using conductive thread and Lilypad boards. We also get a look at a user interface for Summer camp sign-up that was made using Raspberry Pi Zero and a 7″ screen. Other groups were working on custom input projects using Makey Makey and Arduino. The image at the top of this article shows some of the LearnOBots crew with a World Create Day poster, neat!

Appalachian Forge Works in Newland, North Carolina

World Create Day at Appalachian Forge Works brought a baby guitar amp to life on World Create Day. The basic circuit is built around an LM386 amp. It was designed using a whiteboard schematic before moving to the breadboard for prototyping.

For some folks that might be enough of a hacking sessions, but the effort didn’t stop there. An enclosure was designed and laser cut from plywood. This included etching labels for the power button and volume knob. There’s even fabric mesh for the speaker grill for a completely finished look that’s a showpiece even when not belting out some Black Keys.

Baltimore Hackerspace Breaks Out the Welder

Tiny wheels, big motors, and square tubing — it’s almost ready to hit the test track for some time trials. The gang over at Baltimore Hackerspace spent their World Create Day fabricating what surely will be the next championship entry in the Power Racing Series.

After this picture was snapped the team got to work on the control electronics for the racer, which end up in a transparent box between the motors. The team didn’t have time to install a driver’s seat but that didn’t prevent a late night test run.

Sounds of Sewing and Embedded Tinkering at The Bodgery in Madison

I celebrated World Create Day at The Bodgery in Madison, Wisconsin. There were a surprising variety of projects worked on at the meetup, at least three of them using something new to me:

[Josh Lange] brought along the driver boards he’s been designing. I was delighted to see the batteries used in the project. I didn’t realize you could buy 18650 Lithium cells in a consumer-friendly package (like AA batteries but larger) and there are battery holders to go along with them. I’m used to seeing these pulled out of old laptop batteries.

Hackaday’s own [Bob Baddeley] was on hand, working feverishly at the sewing machine. He’s fabricating an entire line of Wacky Waving Inflatable Arm Flailing Tubemen costumes. They use those springy laundry baskets as the internal skeleton. Also being worked on at The Bodgery was an NES expansion port project that will make a custom cartridge hosting a Raspberry Pi Zero utilize the NES video hardware without altering the stock hardware. We also had a fun time working on embedded basics with a software engineer who is getting up to speed with embedded.

Tell Us About Your World Create Day!

We want to hear about what you did on World Create Day. We’ll be covering more events in the coming days so make sure you add your pictures and stories to your WCD event page. Event organizers get a special treat for making that effort. But mainly we want to show off the excitement and ingenuity that was abuzz around the world this past weekend.

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

Life on Contract: Hacking your Taxes

อังคาร, 04/25/2017 - 00:01

You’re a contractor and people are paying you to work in your pajamas. It’s a life of luxury, but when tax time comes, you are in a world of hurt and you wonder why you even do it. Taxes are tricky, but there are some tools you can use to make it less painful on your pocketbook. With planning and diligence, you can significantly increase the amount of money that stays in your bank account.

We are not certified tax lawyers or accountants, so take what follows with a heap of salt, consult appropriate people before you do anything big, and don’t blame us if you get in trouble for anything you do. Also, this advice applies to the United States. If you know some tricks for your country, we’d love to hear them in the comments.


Contractors can do all their work as a person. The company to whom you contract will get your SSN, then submit a 1099 form to the IRS that says “We paid this person $N in this year.” This is easy, there’s very little paperwork, and lots of people do it. However, there are a lot of good reasons why you would be better off incorporating as an LLC and having all your work done through your own business. The biggest reasons are liability and debt. Essentially, if someone sues the LLC, the worst that can happen is you lose the business. Also, if the business runs up debt and then goes bankrupt, the owner doesn’t lose their personal assets. There are lots of caveats to this; if you have to personally cosign a bank loan, for example. Banks aren’t just going to give an LLC a pile of cash without a way to guarantee that they get repaid.

There is a term called “piercing the corporate veil,” which means that in some cases the courts can determine that the LLC is just a shell and you can be sued personally or have your assets seized. This is why it’s important to set up a separate bank account, business cards, a web site, and every other measure possible to show that the business really is a business.

The bottom line is that if you are doing work for someone, then you want to set up a corporation to protect yourself. Setting one up is easy. It’s done through your state’s office, which is usually the Secretary of State, and involves an online form and up to a couple hundred dollars to file (plus a yearly fee to renew). It can be done in an hour or less. Note that in California LLCs have to pay a yearly fee of $800, so if you’re a casual contractor, this is a steep fee. In other states it’s much less. Next you would go to the IRS web site and file for an EIN. This is an online form that takes approximately 3 minutes, and results in an email with your EIN, the number used to identify your business to the IRS.

Next, go to the bank and open up a business checking account. You’ll need the information about the LLC. Finally, buy your domain name, get business cards, and get in the habit of using your business email for all business.


Expenses are an extremely powerful tool in saving money on taxes. In the course of doing business, you take your income, subtract your expenses, and that’s your profit, which is taxed. If you can increase your expenses, then you have less profit that can be taxed. This includes rent for an office, communications (internet and cell phone), office supplies and equipment, travel for work, and a lot of other things that are important in your daily life as a contractor.

As I mentioned before, you should consider incorporating. If you are not incorporated you can still make deductions by filing your 1099 income, and unreported income on a Schedule C. Being incorporated covers more income than just 1099 and unreported work.

Individuals who are not incorporated and do not file a Schedule C may only deduct expenses on their Schedule A by choosing to “itemize” those deductions. But the IRS offers something called “the standard deduction” and if your itemizations are below that threshold, your expenses won’t be counted individually; those expenses don’t help reduce your tax burden.

If you have an LLC, then you can subtract the expenses from the income directly, so that what flows down to you already has the expenses deducted, reducing your taxable income. You will still be able to take the standard deduction in addition to this; it’s your business deducting expenses and you as an individual taking the standard deduction. In other words, having an LLC means you can lower your tax burden more by taking advantage of expenses.

All of these tools are legitimate business expenses.

You can expense a lot more than you think, and it’s important to keep track of it as you go. Every trip you take in your car can be expensed at 53.5 cents per mile, so keep a record of each trip. If you use a room in an apartment for your home office, then the fraction of your apartment’s square footage that is used for the office counts. Your smartphone’s cost and plan are a business expense, as is your internet and computer, and any other equipment you use for your business (like your oscilloscope). You shouldn’t take this too far, though; fraud is illegal, and the IRS gets very unhappy if you try to expense all your food, vacations, and other things that can’t be justified as a business expense. These are expenses for the business, not for your hobby or personal use, so if you use something for both business and personal, you must only count the fraction that is used for business. The IRS probably isn’t going to audit you, but if they do then you want to be able to defend the numbers you gave them.

For all expenses, make sure that you use your business bank account and keep studious records like receipts and mileage logs.


If you work at a corporate job, you may have benefits like health insurance, a 401k with matching, and other perks. As an LLC you can do the same thing, and many of those are expenses that aren’t taxed. Your LLC can pay for your health insurance, or if not then you can deduct the cost of your health insurance on your 1040 if you are self-employed. It’s also possible to set up a solo 401k plan, which lets you contribute towards your retirement, and it lets your LLC contribute to it as well.


All income should be made out to your LLC and go directly into your business bank account. Invoices that you send to your clients should have your business name on them. Make sure that the invoice includes any appropriate taxes. If you don’t collect taxes from your client, you’re still responsible for them, and it eats into your margins. Every year (assuming they pay you more than $600), your clients will have to give you a 1099 form, which says to the IRS “We paid this company $X.” Make sure that the 1099 uses both your business name and the EIN associated with your business.

Paying Yourself

Normally all the net income would flow through to your personal return. You will pay income taxes plus self-employment taxes on this income. Self-employment taxes are the medicare and social security taxes that would be automatically withheld at a normal job, and you can’t escape them by being self-employed. You should definitely be budgeting for these taxes, and you’re supposed to pay the IRS quarterly estimated tax payments. This is one reason why contractors must charge a lot more per hour than what they would make in a salaried job.

There is a neat thing that you can do if you made a decent amount of money, though: the IRS lets you file a form (2553) that allows you to elect for S-Corp taxation. This allows you to get paid two different ways; as a salary and as a distribution. Distributions are not subject to self-employment tax. So if your LLC brings in $100k, you can pay yourself a decent salary like $60k, and pay self-employment and income tax on that, and then give yourself a distribution at the end of the year of $40k, and pay only income tax on that. You have to pay yourself a salary that’s reasonable for your industry, so you can’t avoid the self-employment tax entirely, but this is a great way to avoid having to pay self-employment tax on ALL your income.

Final Notes

There are lots of ways to set up your contracting business so that you can save some money. They’re not especially difficult, and none require a lawyer. Learn about the terms hastily mentioned above and find out if they are appropriate for you. Talk to an accountant. Have them do your taxes for you for the first year and after that if it’s especially messy. They will save you more than they cost, so it’s to your benefit, and the more diligent you are with record-keeping, the more you save.

Do not push the limits. You don’t get to claim that taxes are unconstitutional or that your weekend getaway to Hawaii was a business expense (you can go to Hawaii for training or a conference, but any additional time or activities must be clearly separated as a personal expense). Most likely you will file your taxes and the IRS will just accept them. But if something goes wrong or you push something too far, then you can lose the corporate veil, or the IRS can put you through a painful ordeal. It may not be a full audit, but if they have a question, it’s nice to be able to answer quickly and with certainty. Keep good documentation on your business vs. personal expenses for at least the past 6 years. The trick is to take advantage of opportunities to save, not to flaunt them.

Filed under: Business, Hackaday Columns, lifehacks

Official Launch Of The Asus Tinker Board

จันทร์, 04/24/2017 - 22:30

Earlier this year, a new single board computer was announced, and subsequently made its way onto the market. The Tinker Board was a little different from the rest of the crop of Raspberry Pi lookalikes, it didn’t come from a no-name company or a crowdfunding site, instead it came from a trusted name, Asus. As a result, it is a very high quality piece of hardware, upon which we remarked when we reviewed it.

Unfortunately, though we were extremely impressed with the board itself, we panned the Asus software and support offering of the time, because it was so patchy as to be non-existent. We had reached out to Asus while writing the review but received no answer, but subsequently they contacted us with a sorry tale of some Tinker Boards finding their way onto the market early, before their official launch and before they had put together their support offering. We updated our review accordingly, after all it is a very good product and we didn’t like to have to pan it in our review.

This week then, news has come through from Asus that they have now launched the board officially. There is a new OS version based on Debian 9, which features hardware acceleration for both the Chromium web browser and the bundled UHD media player. There is also an upcoming Android release though it is still in beta at time of writing and there is little more information.

The Tinker Board is one of the best of the current crop of Raspberry Pi-like single board computers, and it easily trounces the Pi itself on most counts. To see it launched alongside a meaningful software and support offering will give it a chance to prove itself. In our original review we urged tech-savvy readers to buy one anyway, now it has some of the backup it deserves we’d urge you to buy one for your non-technical family members too.

Filed under: computer hacks