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Updated: 56 min 8 sec ago

NIST Helps You With Cryptography

1 hour 55 min ago

Getting cryptography right isn’t easy, and it’s a lot worse on constrained devices like microcontrollers. RAM is usually the bottleneck — you will smash your stack computing a SHA-2 hash on an AVR — but other resources like computing power and flash code storage space are also at a premium. Trimming down a standard algorithm to work within these constraints opens up the Pandora’s box of implementation-specific flaws.

NIST stepped up to the plate, starting a lightweight cryptography project in 2013 which has now come out with a first report, and here it is as a PDF. The project is ongoing, so don’t expect a how-to guide. Indeed, most of the report is a description of the problems with crypto on small devices. Given the state of IoT security, just defining the problem is a huge contribution.

Still, there are some concrete recommendations. Here are some spoilers. For encryption, they recommend a trimmed-down version of AES-128, which is a well-tested block cipher on the big machines. For message authentication, they’re happy with Galois/Counter Mode and AES-128.

I was most interested in hashing, and came away disappointed; the conclusion is that the SHA-2 and SHA-3 families simply require too much state (and RAM) and they make no recommendation, leaving you to pick among less-known functions: check out PHOTON or SPONGENT, and they’re still being actively researched.

If you think small-device security is easy, read through the 22-question checklist that starts on page twelve. And if you’re looking for a good starting point to read up on the state of the art, the bibliography is extensive.

Your tax dollars at work. Thanks, NIST!

And thanks [acs] for the tip!

Filed under: Microcontrollers
Categories: Hack-a-Day

These Engineering Ed Projects are Our Kind of Hacks

4 hours 55 min ago

Highly polished all-in-one gear for teaching STEM is one way to approach the problem. But for some, they can be intimidating and the up-front expenditure can be a barrier to just trying something before you’re certain you want to commit. [Miranda] is taking a different approach with the aim of making engineering education possible with junk you have around the house. The point is to play around with engineering concepts with having to worry about doing it exactly right, or with exactly the right materials. You know… hacking!

On display at her Maker Faire Bay Area booth were numerous builds built common goods you likely have on hand. I quite enjoyed seeing the tentacle made of out popsicle sticks, glue, straws, and some string. It’s pretty cool to hold onto one end and pull the string to roll up the appendage, and provides the most basic intro to fabrication and robotics concepts. Think back to some of your earliest empowering moments when you realized you didn’t need purpose-built things like LEGO to build stuff. You can build using anything!

Most popular at the booth is a set of electric banjos. They’re nothing more than a fingerboard, strings, and a piezo element. Connect to a small Radio Shack amp/speaker combo and you get a pretty good sound out of them. [Miranda] added a 3D printed fret board which she plans to make available for those who don’t want to fabricate their own fret system. Along with those, there is a DJ mixing board that used old CDs placed on bottle caps to swivel and have salvage tactile switches underneath to give them interactivity.

There’s a ton to look at on her collection of guides. She gave me a demonstration of her Harry Potter themed wands, one which shoots water and the other that shoots BBs. These would make perfect summer projects to take on one the kids are out of school. There are plans to get a subscription kit biz up and running at some point in the future but the instructions for the builds will always be available free.

Filed under: misc hacks
Categories: Hack-a-Day

Radar Sensors Put to the Test

7 hours 56 min ago

[Andreas Spiess] picked up a few inexpensive radar sensors. He decided to compare the devices and test them and–lucky for us–he collected his results in a video you can see below.

The questions he wanted to answer were:

  • Are they 3.3 V-compatible?
  • How much current do they draw?
  • How long to they show a detection?
  • How far away can they detect the motion of a typical adult?
  • What is the angle of detection?
  • Can they see through certain materials?
  • Can the devices coexist with other devices in the same area? What about WiFi networks?

Good list of questions, and if you want to know the answers, you should watch the video.

The devices he examines are the RCWL-0512, HW-MS03, WB3-12, XYC-WB-D1, and the HFS-DC06. The RCWL module is the least expensive, and we found several places selling them for anywhere from fifty cents to a dollar each. The most expensive module–the HFS-DC06–is about $5.

If you are interested in these, this video will save you a lot of experimentation time. The boards are all somewhat similar, but [Andreas] covers the differences between them early in the video.

We’ve seen cheap radar detectors before, but not this cheap. We’d love to revisit some of the other radar projects we’ve seen in the past and see if they could use these very cheap devices.

Filed under: wireless hacks
Categories: Hack-a-Day

What Lies Within: SMT Inductor Teardown

10 hours 56 min ago

Ever wonder what’s inside a surface-mount inductor? Wonder no more as you watch this SMT inductor teardown video.

“Teardown” isn’t really accurate here, at least by the standard of [electronupdate]’s other component teardowns, like his looks inside LED light bulbs and das blinkenlights. “Rubdown” is more like it here, because what starts out as a rather solid looking SMT component needs to be ground down bit by bit to reveal the inner ferrite and copper goodness. [electronupdate] embedded the R30 SMT inductor in epoxy and hand lapped the whole thing until the windings were visible. Of course, just peeking inside is never enough, so he set upon an analysis of the inductor’s innards. Using a little careful macro photography and some simple image analysis, he verified the component’s data sheet claims; as an aside, is anyone else surprised that a tiny SMT component can handle 30 amps?

Looking for more practical applications for decapping components? How about iPhone brain surgery?

[via Dangerous Prototypes]

Filed under: misc hacks, teardown
Categories: Hack-a-Day

Only 90s Kids Will Appreciate This Prototype

13 hours 56 min ago

[Madox] is a trackball user, which is fine; we at Hackaday respect and appreciate those who live alternative lifestyles. As you would expect, there aren’t many makes and models of trackballs being sold, and [Madox] wanted something ergonomic. A DIY solution was necessary, but how to you model something ‘ergonomic’ before printing it out? Floam, apparently.

Highly advanced 3D prototyping skills

Floam is a sticky, moldable goo originally sold as the follow-up to Nickelodeon’s Gak in the early 1990s. It consists of styrofoam pellets held together with a colored binder that doesn’t leave a mess and doesn’t dry out. While the Nickelodeon version is lost to the sands of time, a Floam-like substance is available at any toy store. [Madox] picked up a few blister packs and began modeling his ideal trackball.

With the proper shape in hand, [Madox] needed a way to get this design into a computer. Photogrammetry is the solution, and while earlier experiments with Autodesk Catch were successful, Autodesk has morphed and rebranded their photogrammetry software into Autodesk ReMake. Turing a pile of styrofoam balls into a 3D model is as simple as taking a bunch of pictures and uploaded to Autodesk’s ‘cloud’ service.

In just a few minutes, a proper 3D mesh arrived from the Autodesk mothership, and [Madox] took to importing this model into Fusion 360, fiddling with chamfers, and eventually got to the point where a 3D printer was necessary. It took a few revisions, but now [Madox] has a custom designed trackball that was perfectly ergonomic.

Filed under: peripherals hacks
Categories: Hack-a-Day

Fooling Samsung Galaxy S8 Iris Recognition

16 hours 55 min ago

We have a love-hate relationship with biometric ID. After all, it looks so cool when the hero in a sci-fi movie enters the restricted-access area after having his hand and iris scanned. But that’s about the best you can say about biometric security. It’s conceptually flawed in a bunch of ways, and nearly every implementation we’ve seen gets broken sooner or later.

Case in point: prolific anti-biometry hacker [starbug] and a group of friends at the Berlin CCC are able to authenticate to the “Samsung Pay” payment system through the iris scanner. The video, embedded below, shows you how: take a picture of the target’s eye, print it out, and hold it up to the phone. That was hard!

Sarcasm aside, the iris sensor uses IR to recognize patterns in your eye, so [starbug] and Co. had to use a camera with night vision mode.  A contact lens placed over the photo completes the illusion — we’re guessing it gets the reflections from room lighting right.  No etching fingerprint patterns into copper, no conductive gel — just a printout and a contact lens.

We’ve ranted about the insecurity of fingerprints before; they’re not a good secret, they’re irrevocable, and they’re hard to store securely. And on top of these conceptual problems, they’re quite spoofable, as [starbug] and many others have shown, going way back.

So why do we still use them? Fingerprint readers and iris scanners are “good enough” security and they’re fun to hack around with. Should you add one to your project for grins? Absolutely. Should you require your citizenry to use them for authentication, or use them for real security? We wouldn’t.


Thanks [mbln] for the tip!

Filed under: security hacks
Categories: Hack-a-Day

Hackaday Prize Entry: Underwater Glider Offers Low-Power Exploration

17 hours 55 min ago

[Alex Williams] created his Open Source Underwater Glider project as an entry to The Hackaday Prize, and now it’s one of our twenty finalists. This sweet drone uses motor-actuated syringes to serve as a ballast tank, which helps the glider move forward without the use of traditional propellers.

Unlike most UAVs, which use motors to actively move the craft around, [Alex]’s glider uses the syringes to change the buoyancy of the craft, and it simply glides around on its wings. When the craft starts getting too deep, the syringes push out the water and the glider rises toward the surface until it’s ready for another glide.

This low-power solution allows for long-term science projects and research. In addition to conserving power, the glider’s slow travel does not disturb the water or sea life.

[Alex]’s goal is to make his glider open source and 3D printable, combined with off-the-shelf hardware and ArduSub under the hood.

The HackadayPrize2017 is Sponsored by:

Filed under: The Hackaday Prize
Categories: Hack-a-Day

Hackaday’s BAMF Meetup Spills into the Streets of San Mateo

18 hours 54 min ago

Saturday night marked the fourth annual Hackaday BAMF meetup. The night when weary exhibitors close up their booths at Bay Area Maker Faire and head over to O’Neil’s Irish Pub where the real fun starts. There are many drawbacks to having a booth; you’re on your feet all day repeating the same small snippet to everyone passing by, and usually you don’t get much of a chance to mingle with friends old and new.

Walking into the meetup, it was striking to watch aching bodies slow with weariness perk up to the energy and excitement of the Hackaday Community incarnate. Join me after the break for a peek into the fun of the evening.

The place filled up fast and our geekdom chased out the locals faster than in previous years. The bar was packed to capacity, cleared out a bit, and was packed again until late in the evening. I figure we were still at about 60% of capacity when I snuck away for the night at about 1 AM. You can see above that the party spilled out in the street at one point. A keen eye will pick out Paul Stoffregen (creator of Teensy) finding a quieter and cool place for a conversation.

We applied a bit of social media pressure to convince Joseph Prusa to stop by. Here you can see him taking a look at the tiny portable 3D printer that Whosawhatsis brought along with him. We snapped a candid shot of Chris Gammel catching up with Hackaday Prize judge Dr. Christal Gordan and our good friend Krux who runs DEF CON Darknet. (He showed me this year’s badge but forbade me to take pictures.) If you’re into titans of media you could hang out with Karl Bowers of The Spark Gap podcast and Ben Heckendorn of the Ben Heck show.

Wearables were popular this year. Someone brought along a HoloLens (I can call that a wearable, right?). Shawn Hymel from Sparkfun seems waaaay to excited to see Shulie trying the headset out. An EL wire hat fit in quite well at the meetup. And it was great to run into a binary wristwatch that was built around a Silicon Labs microcontroller for a nice change from the oft-featured AVR and PIC offerings.

There was a little robot whose purpose was to pass the beer (oh… my-god). We were treated to a demo of an in-progress software defined radio. You can get a close look at the board above. The wide shot shows the frequency counter verifying what the transmitter is putting out.

All in all an amazing night, and one that made hitting the third day of the fair in 90 degree weather all the harder. But it was certainly worth it. Thanks for everyone who stopped by, there are a few more pictures to look through on If you didn’t make it to this meetup, you missed something special — mark your calendars for next year!

Hackaday crew huddled in the back of O’Neil’s for a quick group shot.
Filed under: cons
Categories: Hack-a-Day

On Point: The Yagi Antenna

19 hours 54 min ago

If you happened to look up during a drive down a suburban street in the US anytime during the 60s or 70s, you’ll no doubt have noticed a forest of TV antennas. When over-the-air TV was the only option, people went to great lengths to haul in signals, with antennas of sometimes massive proportions flying over rooftops.

Outdoor antennas all but disappeared over the last third of the 20th century as cable providers became dominant, cast to the curb as unsightly relics of a sad and bygone era of limited choices and poor reception. But now cheapskates cable-cutters like yours truly are starting to regrow that once-thick forest, this time lofting antennas to receive digital programming over the air. Many of the new antennas make outrageous claims about performance or tout that they’re designed specifically for HDTV. It’s all marketing nonsense, of course, because then as now, almost every TV antenna is just some form of the classic Yagi design. The physics of this antenna are fascinating, as is the story of how the antenna was invented.

“Uda Who?” Shintaro Uda. Source: IEEE Cincinnati Section

What would come to be known as the Yagi antenna got its start in the early 1920s in the lab of Professor Shintaro Uda in the Tohoku Imperial University in Sendai Japan. Dr. Uda was working in the VHF band and was looking for ways to make antennas more directional. While experimenting with a resonant loop antenna, he discovered that placing a static loop near the antenna tended to shape the signal away from an omnidirectional pattern, almost as if the loop was acting as a reflector.

Together with his colleague Hidetsugu Yagi, Uda experimented with different configurations. They eventually replaced the loop antenna with a simple dipole, and added additional elements, which they called directors, on a long boom to further shape the beam. Using eight directors on a 15-meter wooden boom mounted to the roof of their laboratory, Uda and Yagi were able to communicate over a distance of 135 km at 68 MHz, no mean feat at the time.

Hidetsugu Yagi and “his” antenna. Source: Physics

Having dubbed their invention the “wave projector directional antenna,” it was inevitable that the antenna would be named after someone. How it came to be credited solely to Dr. Yagi is a tale of some treachery on Yagi’s part with a dash of naiveté on Uda’s. Dr. Uda published the first Japanese language papers on the antenna, but for reasons unknown, Dr. Yagi applied for both Japanese and American patents for the antenna with no mention of Uda. The Japanese patent was assigned to the Marconi Company in England, while the American patent went to RCA. With no mention of Uda, and with Dr. Yagi touring the English-speaking world to discuss “his” antenna at various radio engineering conferences, the antenna gradually became simply the “Yagi antenna” or the “Yagi array.”

Ironically, thanks to inter-service rivalries and a silo mentality in Imperial Japan, it was only the capture of a British radar set during the Battle of Singapore in 1942 that introduced the homegrown invention to the Japanese military. The Japanese intelligence officers didn’t even consider “Yagi” to be a Japanese name — they supposed it was just a code word made up by the British.


The chief characteristics of the Yagi-Uda antenna are high directionality and high gain. Given the fact that the length of each element needs to be close to some fraction of the wavelength of the signal, it’s most practical for the higher frequencies, mostly above 30 MHz. That’s not to say that it can’t be used for the longer wavelengths, though — plenty of hams work the 20 m and 40 m bands through a big Yagi.

A Yagi for the ham bands. Note the driven element with feedline, seven directors, and a single reflector. Source:

As in Dr. Uda’s original design, a Yagi consists of a single driven element parallel to and coplanar with at least two parasitic elements. A minimal design is a single reflector element located “behind” the driven element (relative to the direction of the radio signal) and a single director element in front of the driven element. A practical antenna is likely to have multiple directors, the more of which there are the tighter the directionality and the higher the gain, at least up to a point.

This gives Yagis their characteristic appearance – a horizontal boom with multiple elements arranged perpendicularly. There are some variations, of course — some Yagis have multiple reflectors, or have a corner reflector arrangement. And some antennas, particularly TV antennas, have the parasitic elements swept back at an angle rather than perpendicular to the boom. Additionally, the elements can be arranged horizontally or vertically, depending on the polarization desired.


To understand the Yagi’s design, recall that a plain old dipole antenna in free space has a radiation pattern that is the strongest broadside to the antenna. That results in two big lobes off the front and the back of the antenna, with little signal off the ends. The driven element of a Yagi is just a half-wave dipole, or sometimes a folded dipole to increase the impedance. The parasitic elements shape and direct the beam using constructive and destructive interference.

As Dr. Uda discovered, the parasitic elements can either be inductively or capacitively coupled to the driven element. Inductive elements are slightly longer than half-wave, while capacitive elements are slightly shorter. The directors are all shorter than half-wave and are therefore capacitively coupled, while the reflector is longer and inductively coupled. The difference from the ideal half-wave is small — usually only 10% to 15%.

Constructive and destructive interference in a Yagi antenna. The green wave represents the sum of the red and blue waves. Source:

Both the reflector and the directors work by reradiating power from the driven element. The spacing of the parasitic elements relative to the driven element determines the phase of the reradiated signal. The reflector, being inductively reactive, reradiates power 180° out of phase with the driven element. The spacing is set so that this causes destructive interference off the back of the antenna, while at the same time being nearly in-phase with the driven signal off the front of the antenna. This results in constructive interference, boosting the power off the front. Similarly, the capacitively coupled directors are spaced so that they reradiate power more-or-less in-phase in the forward direction, while radiating out-of-phase to the rear.

The result is greatly amplified signal toward the directors, and almost none behind the reflector. And recall that antenna theory states that any antenna that transmits can also receive, and with the same characteristics. It doesn’t matter whether the driven element in a Yagi is driven by a 100-watt power transmitter connected to the feedline, or by a few microwatts picked up from a distant TV tower. The directionality and gain will be the same. And Yagis can have remarkable gain – up to 20 dBm when correctly designed.

As useful as the Yagi antenna is, it’s far from perfect. Because of the critical size and spacing of the parasitic elements, Yagis have a relatively narrow bandwidth. Also, the directionality of the antenna can be an inconvenience, requiring that the antenna be rotated to point more or less exactly at the transmitter or receiver.

But if you need to pull in a single distant signal, that directionality is just what you need. The Yagi is a workhorse antenna, and given the impact it has had it’s probably right and good that many have taken to referring to it as the Yagi-Uda antenna.


Filed under: Engineering, Featured, History, wireless hacks
Categories: Hack-a-Day

Friday Hack Chat: Antiquated Technologies With Fran Blanche

20 hours 55 min ago

Join us this Friday for a Hack Chat on antiquated technologies.

Every Friday, we round up someone from the hardware scene and sit them down in front of a keyboard to discuss what they’re working on. This week, we’re talking with [Fran Blanche] to discuss ancient technologies, weird electronics, and everything that goes into building a hardware company from the ground up.

Who’s [Fran Blanche], you might ask? She’s a self-taught electronic engineer, artist, musician, photographer, mechanical engineer, and YouTube vlogger. She’s the founder of Frantone Electronics, one of the very first manufacturers of boutique guitar effects. Her Peachfuzz is one of the very, very few original distortion/fuzz circuits out there. She’s given talks at Brown University on the boutique effects industry, worked with the Franklin Institute on the Maillardet Automaton, wandered around the largest musical instrument, taken apart flight hardware from the Saturn V just to see how it works, and she’s been inside the warehouse for the Smithsonian’s Air and Space museum.

With a resume of work this cool, what’s [Fran] working on now? She’s trying to recreate the DSKY from the Apollo Guidance Computer. The DSKY is the user interface for the Apollo Guidance Computer, a wonderful block of aluminum studded with beautiful buttons and electroluminescent displays. For the last few years, her attempts to reproduce a modern DSKY — including the custom segmented EL display — has been on the back burner, but now [Fran] is attempting to raise the money for a reproduction on GoFundMe. I encourage you all to at least look at that GoFundMe campaign.

Here’s How To Take Part:

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

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

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

Filed under: Hackaday Columns
Categories: Hack-a-Day

[Bre Pettis] Buys Other Machine Co.

Wed, 2017-05-24 23:01

Other Machine Co., manufacturer of the very capable and very cool OtherMill Pro CNC machine, has been acquired by [Bre Pettis], former CEO of MakerBot. Under the terms of the acquisition, current CEO of Other Machine Co, Dr. Danielle Applestone, will remain in charge of the company.

We have a love affair with the OtherMill here at Hackaday. We have a few of them kicking around the Design Lab, and they’re great. Six mil traces are possible, and the OtherMill is a very reliable machine. We’ve taken a look at the OtherMill manufacturing process and liked what we saw, and we’ve invited [Danielle Applestone] to talk about the quest for the highest precision per dollar.

Of course, the newsworthy item for this, ‘rich guy buys a company’ story is who acquired the company. [Pettis] is most famous for being one-third of the original MakerBot team, a position that netted him about $130 Million after Stratasys acquired MakerBot. Stratasys’ acquisition of MakerBot has made a lot of people angry and has been widely regarded as a bad move. The history of MakerBot is not written yet, but the general consensus is that [Pettis] only played a very limited role in the downfall of MakerBot and desktop 3D printing as a whole.

Since leaving MakerBot for greener pastures, [Pettis] has put his money to work; he’s also an investor in the laser cutter startup Glowforge. While Glowforge has seen its share of troubles including a ridiculous policy on field-replaceable laser tubes, and perpetual delays for production units, Glowforge will be shipping soon. It’s unclear how the Glowforge will ultimately be received. But [Pettis’] continues to put his money where his mouth is (and into hardware startups) with this acquisition of Other Machine Co..

Filed under: news, tool hacks
Categories: Hack-a-Day

First Look at ABC: Basic Connections

Wed, 2017-05-24 22:01

[Alberto Piganti], aka [pighixxx] has been making circuit diagram art for a few years now, and has just come out with a book that’s available on Kickstarter. He sent us a copy to review, and we spent an hour or so with a refreshing beverage and a binder full of beautiful circuit diagrams. It doesn’t get better than that!

[pighixxx] started out making very pretty and functional pinout diagrams for a number of microcontrollers, and then branched out to modules and development boards like the Arduino and ESP8266. They’re great, and we’ll admit to having a printout of his SMD ATMega328 and the ESP-12 on our wall. His graphical style has been widely copied, which truly is the sincerest form of flattery.

But after pinouts, what’s next? Fully elaborated circuit diagrams, done in the same style, of course. “ABC: Basic Connections” started out life as a compendium of frequently used sub-circuits in Arduino projects. But you can take “Arduino” with a grain of salt — these are all useful for generic microcontroller-based projects. So whether you want to drive a 12 V solenoid from a low-voltage microcontroller, drive many LEDs with shift registers, or decode a rotary encoder, there is a circuit snippet here for you.

One of the things that we like most about the graphics in “ABC” is that they’re not dumbed down — they’re fundamentally just well-done circuit diagrams, but with graphic touches and extra detail where it actually helps to clarify things. This is a middle ground between the kind of schematic you use in a PCB layout program and the kind of diagram you get from Fritzing. In the former, every part has a symbol but multifunction parts like microcontrollers are just represented as squares bristling with pin numbers. In the latter, wiring up an IC is easy because the parts and pins are represented graphically, but you quickly run out of colors for the different wires, and the “breadboard” turns into a rat’s nest with a circuit of any complexity.

“ABC” takes the middle road, using standard circuit diagram style overall, but also the nice graphic representations of the ICs and modules that [pighixxx] is good at. Is a 2N2222 pinned EBC or BCE? You don’t have to look that up, because it’s sketched out for you here. We’d guess that this attractive, but information-rich, style is a great fit for the target audience — people with some electronics experience who do not yet have their favorite transistor symbol tattooed on their forearm. [pighixxx]’s diagrams are simple, easy to understand, easy to use, and pretty to boot.

There is a planned online counterpart to the book, with further elaborations of all of the circuit setups. They’re not finished yet, but they have a lot more of the flavor of the Fritzing-style, this-wire-goes-to-that-hole diagrams. This style does work better in an online format than in a physical book, because you can build up the rat’s nest in bite-sized steps, none of which are too overwhelming. But honestly, for an advanced beginner or intermediate electronics hacker, the book can be treated as stand-alone. The web content may help the rank newbie when they get stuck.


The breadth of circuits in “ABC” is fairly wide, covering most of the microcontroller-interfacing problems that we’ve ever encountered. None of the circuits are revolutionary — they’re the tried-and-true, correct solutions to the various problems, rather than anything too hacky or clever. We weren’t surprised by any of the circuits, but we didn’t find anything that we wouldn’t use ourselves either. These are basic connections after all, and a darn solid collection of them.

To sum up, “ABC” is an attractive book in a handy binder format that would make a great collection of solutions for anyone who’s just getting started in the whole “Arduino” scene but who gets hung up on interfacing the chips with the real world. It’s a handy reference for the pinouts of a number of frequently used parts, combined with the resistors, flyback diodes, level-shifting circuits, and whatever else that you’d need to make them work. It’s what we wish our simple circuit diagrams looked like. We like it.

Filed under: Hackaday Columns, reviews, slider
Categories: Hack-a-Day

Practical Enclosure Design, Optimized for 3D Printing

Wed, 2017-05-24 19:00

[3D Hubs] have shared a handy guide on designing practical and 3D printing-friendly enclosures. The guide walks through the design of a two shell, two button remote control enclosure. It allows for a PCB mounted inside, exposes a USB port, and is optimized for 3D printing without painting itself into a corner in the process. [3D Hubs] uses Fusion 360 (free to hobbyists and startups) in their examples, but the design principles are easily implemented with any tool.

One of the tips is to design parts with wall thicknesses that are a multiple of the printer’s nozzle diameter. For example, a 2.4 mm wall thickness may sound a bit arbitrary at first, but it divides easily by the typical FDM nozzle diameter of 0.4 mm which makes slicing results more consistent and reliable. Most of us have at some point encountered a model where the slicer can’t quite decide how to handle a thin feature, delivering either a void between perimeters or an awkward attempt at infill, and this practice helps reduce that. Another tip is to minimize the number of sharp edges in the design, because rounded corners print more efficiently and with smoother motions from the print head.

The road to enclosures has many paths, including enclosures made from FR4 (aka PCB material) all the way down to scrap wood with toner transfer labeling, and certainly desktop 3D printing has been a boon to anyone who’s had to joylessly drill and saw away at a featureless plastic box.

Filed under: 3d Printer hacks, how-to
Categories: Hack-a-Day

Tightwad Hacks Label Printer, Beats Manufacturer at Own Game

Wed, 2017-05-24 16:00

Sometimes we hack for the thrill of making something new, and sometimes we hack to push back the dark veil of ignorance to shed fresh light on a problem. And sometimes, like when turning a used label printer into a point-of-sale receipt printer, we hack because we’re cheapskates.

We say that with the utmost respect and affection — there’s nothing to be ashamed of when your motive is strictly pecuniary. In [Dan Herlihy]’s case, hacking a cheap Brother label printer to use thermal paper meant saving $300 on a dedicated receipt printer. But it also meant beating Brother at their “Razor and Blades” business model that keeps you buying their expensive proprietary labels. A pattern of holes in the plastic label roll tells the printer what size labels are loaded, so [Dan] defeated that by breaking off a piece of the plastic and gluing it on the sensor. To convince the printer that plain thermal paper is label stock, he printed up a small strip of paper with the same pattern of black registration stripes that appear on the back of the labels. Pretty clever stuff, and it lets him print high-resolution receipts for his electronics shop on the seriously cheap.

[Dan]’s hack is simple, but may suffer from wear on the paper encoder strip. Perhaps this Brother hack using the gears as encoders will provide some inspiration for long-term fix.

Filed under: misc hacks, peripherals hacks
Categories: Hack-a-Day

Bring Home a Classic Synth with the DIY Fairlight CMI

Wed, 2017-05-24 13:00

[Davearneson] built a modern version of a classic synthesizer with his DIY Fairlight CMI. If there were a hall of fame for electronic instruments, the Fairlight CMI would be on it. An early sampling synth with a built-in sequencer, the Fairlight was a game changer. Everyone from A-ha to Hans Zimmer has used one. The striking thing about the Fairlight was the user interface. It used a light pen to select entries from text menus and to interact with the audio waveform.

The original Fairlight units sold for £18,000 and up, and this was in 1979. Surviving units are well outside the price range of the average musician. There is an alternative though – [Peter Vogel] has released an iOS app which emulates the Fairlight.

[Davearneson] had an old iPad 2 lying around. Too slow to run many of the latest apps, but just fast enough to run the Fairlight app. An iPad doesn’t exactly look like a classic instrument though. So he broke out the tools and created a case that looked the part.

The front of the case is made of framing mat board. The rest of the shell is wood. [Davearneson] used Plasti-Dip spray to replicate the texture of 1970’s plastics. The audio interface is a Griffon unit, which provides audio and MIDI connections. [Davearneson] extended the connections from the Griffon to the rear of the case, making for a clean interface.

The iPad doesn’t exactly support a light pen, so a rubber tipped stylus on a coil cord takes it place. The result is a device that looks and works like a Fairlight – but doesn’t need a steady diet of 8″ floppy discs to operate.

Interested in classic digital synthesizers that are a bit more budget friendly? Check out Al Williams’ article on the SID chip, or this 3D printed synth based upon the 4046 PLL chip.

Filed under: musical hacks
Categories: Hack-a-Day

Run From the Sound of Footsteps in Blind Game of Tag

Wed, 2017-05-24 10:00

The human auditory system is a complex and wonderful thing. One of its most useful features is the ability to estimate the range and direction of sound sources – think of the way people instinctively turn when hearing a sudden loud noise. A team of students have leveraged this innate ability to produce a game of tag based around nothing but sound.

The game runs on two FPGAs, which handle the processing and communication required. The chaser is given a screen upon which they can see their own location and that of their prey. The target has no vision at all, and must rely on the sounds in their stereo headphones to detect the location of the chaser and evade them as long as possible.

The project documentation goes into great detail about the specifics of the implementation. The game relies on the use of the Head Related Transfer Function – a function related to how the ear picks up sounds relative to their position. This allows the FPGA to simulate the chaser’s footsteps, and feed the audio to the target who perceives the chaser’s position purely by sound.

It’s a great example of a gameplay mechanic that we’d love to see developed further. The concept of trying to find one’s way around by hearing alone is one which we think holds a lot of promise.

With plenty of processing power under the hood, FPGAs are a great choice for complex audio projects. A great project to try might be decoding MP3s.


Filed under: FPGA
Categories: Hack-a-Day

Google Home Meets ESP8266

Wed, 2017-05-24 07:00

[Luc Volders] is building his own smart house with the help of Google Home and an ESP-8266. Inspired by the house computers from the TV show, Eureka [Luc] created an IoT ecosystem using a mix of off the shelf devices and open source software.

There are about a thousand ways to create a DIY smart home these days. All of them involve setting up a command receiver (like Amazon’s Echo or Google Home), some sort of cloud connection, and an end device controller. This can get complex for the beginner. [Luc’s] article is great because he walks is through each step tutorial style. He even keeps things simple by programming the ESP8266 using BASIC with ESP-BASIC.

[Luc] uses If This Then That (IFTT) as his cloud service. IFTT is the glue between Google’s cloud service and the ESP8266 connected to his home WiFi network. Speaking of which, [Luc] shows how to set up port forwarding on the router so all accesses to port 8085 go to the ESP8266. Not exactly strong security – but it’s better than opening the entire home network.

You don’t need a real Google home device for this hack. You can build your own with a Raspberry Pi. Once that is set up you can do everything from turning on lights to watering your lawn.

Filed under: home hacks
Categories: Hack-a-Day

Arise, Chicken, Arise!

Wed, 2017-05-24 04:00

A couple of months ago, [Mike] started saving bones from all the fried chicken he had been eating. If that’s the opening line, you know it’s going to be good.

This Cyborg Chicken project grew out of [Mike]’s love for battlebots, and an immense dearth of battleborgs. The difference, though small, is distinct: a robot is simply a machine that carries out instructions either automatically or via remote control. A cyborg, on the other hand, contains both organic and biomechatronic body parts. Since [Mike] was saving chicken bones, he stumbled upon the idea of creating a cyborg out of trash, a few servos, an MSP430, and some other parts sitting around in his junk drawer.

A continuation of an earlier remote controlled food project, the capabilities of these chicken battleborgs are about what you would expect: they roll around on wheels and flail their drumsticks wildly. [Mike] has already built at least two of these devices, and the result is accurately described as Rock ’em Sock ’em Borgs. Check out the video below for the action.

On the hardware side of things, [Mike] picked up an MSP430, and whipped up a bit of code in Java. Three billion enterprise computing systems and, now, two cyborg chickens run Java. The motors and drivers come from Pololu, and control is provided over IR with a pair of Atari joysticks.

You can check out the videos of these cyborg chickens below. If you have to ask why, the answer is always, ‘because’.

Filed under: robots hacks
Categories: Hack-a-Day

Hackaday Prize Entry: Rangefinder + Camera = SmartZoom

Wed, 2017-05-24 02:30

The interesting thing about submissions for The Hackaday Prize is seeing unusual projects and concepts that might not otherwise pop up. [ken conrad] has a curious but thoughtfully designed idea for Raspberry Pi-based SmartZoom Imaging that uses a Pi Zero and camera plus some laser emitters to create a device with a very specific capability: a camera that constantly and dynamically resizes the image make the subject appear consistently framed and sized, regardless of its distance from the lens. The idea brings together two separate functions: rangefinding and automated zooming and re-sampling of the camera image.

The Raspberry Pi uses the camera board plus some forward-pointing laser dots as a rangefinder; as long as at least two laser dots are visible on the subject, the distance between the device and the subject can be calculated. The Pi then uses the knowledge of how near or far the subject is to present a final image whose zoom level has been adjusted to match (and offset) the range of the subject from the camera, in effect canceling out the way an object appears larger or smaller based on distance.

We’ve seen visible laser dots as the basis of rangefinding before, but never tied into a zoom function. Doubtlessly, [ken conrad] will update his project with some example applications, but in the meantime we’re left wondering: is there a concrete, practical use case for this unusual device? We have no idea, but we’d certainly have fun trying to find one.

The HackadayPrize2017 is Sponsored by:

Filed under: digital cameras hacks, Raspberry Pi, The Hackaday Prize
Categories: Hack-a-Day

The Textile Bench

Wed, 2017-05-24 01:01

What’s on your bench? Mine’s mostly filled with electronic test equipment, soldering kit, and computers. I’m an electronic engineer by trade when I’m not writing for Hackaday, so that’s hardly surprising. Perhaps yours is like mine, or maybe you’ve added a 3D printer to the mix, a bunch of woodworking tools, or maybe power tools.

So that’s my bench. But is it my only bench? On the other side of the room from the electronics bench is a sturdy folding dining table that houses the tools and supplies of my other bench. I’m probably not alone in having more than one bench for different activities, indeed like many of you I also have a messy bench elsewhere for dismantling parts of 1960s cars, or making clay ovens.

My textile bench, with a selection of the equipment used on it.

The other bench in question though is not for messy work, in fact the diametric opposite. This is my textile bench, and it houses the various sewing machines and other equipment that allow me to tackle all sorts of projects involving fabric. On it I’ve made, modified, and repaired all sorts of clothing, I’ve made not-very-successful kites, passable sandals, and adventurous tent designs among countless other projects.

Some of you might wonder why my textile bench is Hackaday fodder, after all it’s probably safe to assume that few readers have ever considered fabricating their own taffeta ball gown. But to concentrate only on one aspect of textile work misses the point, because the potential is there for so much cross-over between these different threads of the maker world. So I’m going to take you through my textile bench and introduce you to its main tools. With luck this will demystify some of them, and maybe encourage you to have a go.

Hand Tools and Measurement

You might expect this article to head directly for the machine tools, the sewing machines. But they are only part of the picture, and it is how the rest of the tools that surround them are used that makes the difference between textile success and failure.

First up are my collection of scissors and shears. I have three pairs, a big orange handled set of fabric shears for cutting fabric, a set of normal domestic scissors for cutting pattern pieces and other paper, and a set of tiny scissors for getting into small spaces for snipping thread or similar. These should be taken care of, in particular the fabric shears. Blunt or damaged shears can damage your fabric, so woe betide anyone who picks up mine and cuts anything but fabric with them.

My stitch ripper. Very useful tool, it covers up for my mistakes.

The smallest and probably the cheapest tool on my textile bench is my stitch ripper. This is a combination of hook, spike, and knife, which is like a universal delete button for textilists. With it you can unpick seams, either to dismantle an item for remodeling or most likely, to undo your inevitable mistakes. This and the shears really are the tools you have to hand the most on your textile bench.

The metrology requirements of a textilist are less demanding than those of an electronic engineer, so the closest thing to an instrument on my textile bench is a fabric tape measure. Why a fabric one, you ask? Imagine having a measurement taken with a cold spring steel engineer’s tape measure. Unexpectedly from an engineering perspective I do my textile measurements in inches rather than millimetres, they seem to be the unit of choice in the field.

Sundries And Consumables

In the picture above, you’ll see a range of sundries and consumables. Minor components of your project, or small parts used in their construction. Most obvious are the pins, I have a pincushion full of dressmaker’s pins, each about an inch long with a small plastic ball on one end. Pins are the universal fixer of textile work, they are used to hold everything in place exactly as it should be before sewing. I’ll thus often have a piece of work with a lot of them in at once, and have to be careful to remove them afterwards. In the case of pinned-together seams, the pins are removed anyway as you feed them into your sewing machine.

As for consumables, you’ll find elastic, iron-on interfacing — like a stick-on fabric stiffener and support, repair tape, and a box of spools of thread in my workbox. There is also a box of sewing machine bobbins ready loaded with different coloured threads, and because I have two sewing machines of vastly different ages I have to keep two different bobbin sizes.

Sewing Machines And Overlockers Cue a comment thread about plastic gears…

Having dealt with the small stuff, we come to the machines. I have a couple of sewing machines and an overlocker, which are each used for doing seams to join fabric in their own particular way.

My main sewing machine is a modern Singer domestic machine. It has been mine for several years now, it has a basic computerized management of a huge range of specialized stitches, and with it I’ve built all sorts of projects. I’ve talked in the past about selecting a sewing machine for your bench at all levels, but I can recommend a similar everyday modern machine as a workhorse if you can afford it.

From a time when you had to be a weightlifter to own a sewing machine.

The other sewing machine on my bench is a vintage Singer from the 1950s, a 201K. It does only one stitch, a straight line, but it does that better and more robustly than almost any machine you could find today. It is built to a standard that exceeds that of many modern heavy-duty or industrial machines, and in fact that is what I use it for. It comes out for leather, footwear, canvas, tentage, awnings, or other projects the domestic machine would struggle over.

A 201K does however weigh as much as a small battleship, and is not a machine for the faint-hearted to move.

The final machine on my textile bench is a Janome overlocker. If you are unfamiliar with an overlocker, think of it as a machine for creating seams and finishing them such that they don’t fray. When you simply sew two pieces of fabric together with a single line of stitching and without any techniques to protect the edge, the cut edge of the fabric has nothing to secure it, and thus its weaving starts to come apart. The overlocker prevents this by extending a stitch over the cut edge from above and below, in effect protecting the cut edge. You can see this clearly in the accompanying picture, on the left is a fraying seam edge done with the Singer, on the right an overlocked one from the Janome.

This functionality comes with the trade-off of an overlocker being a much more complex machine than a straightforward sewing machine. It has four spools of thread and two needles which are rather more complex to set up, and it has an oscillating knife blade which cuts a straight edge on the fabric.

An overlocker is probably not something you will find on the second-hand market as readily as you would a sewing machine, they are not such a ubiquitous piece of domestic equipment that everybody’s mother or grandmother would have had. However if you have the chance to pick one up cheaply or you can afford to buy a new one then they are very much worth the effort, this is a machine that will take your textile work to the next level.

There is one final piece of textile equipment that doesn’t sit on my bench, it’s simply too big for that. A tailor’s dummy is an extremely useful tool, a human-shaped former onto which you can pin fabric or pattern pieces to create shapes in 3D. I use mine for adjusting the fit of part-built garments, as a former to get the shape I need when taking something in, and for laying pieces of tracing paper to create my own patterns. It was an enabling moment for my textile work, taking me off the 2D table and into the third dimension allowed me to get to grips with my own patterns in a way I had never done before.

One size, fits only me.

If you are looking for a tailor’s dummy, you might be lucky enough to find one second-hand. Purpose built ones are adjustable across a range of sizes and are not exactly cheap when bought new, but fortunately if all you will ever need is one size there is a cheap alternative. My tailor’s dummy is a fake one manufactured from expanded polystyrene with a fabric cover for shop window displays, these are available in a range of sizes and don’t cost a huge amount. Mine came from Amazon, and cost me around £20 ($25).

All this equipment represents a fairly well-equipped textile bench, It takes up quite a lot of space, and I haven’t even shown you the boxes containing my stocks of random fabrics or patterns. If you have an interest in textiles you don’t have to buy all the equipment shown here, this represents the accumulated result of quite a few years. But if you take a look at the hand tools and consumables then pair them with a serviceable domestic sewing machine you should be equipped to tackle most textile builds, and it needn’t cost an arm and a leg. Even if it might sometimes cover them.

Filed under: Hackaday Columns, Skills, slider, tool hacks
Categories: Hack-a-Day