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Updated: 1 hour 32 min ago

Sandwich Together a Raspberry Pi Laptop

2 hours 31 min ago

Ever since the Raspberry Pi was released to an eager public just over five years ago there is one project that seems to have been tackled more frequently than any other using the small computer from Cambridge: that of making a laptop with Pi for brains. Perhaps you feel you have had your fill of Pi laptops both good and bad, but it’s still a project that can bring up some surprises.

Does [Eben] carry a silver marker with him at all times, laptops for the signing of?[Archie Roques] is a young maker from Norwich, UK, and at the Raspberry Pi birthday party in early March he had rather an unusual laptop. He’d done the usual thing of mating the official Pi screen, a bluetooth keyboard/touchpad, Pi, and battery, but as always it’s the detail that matters. His case is a carefully designed sandwich of laser-cut plastic that somehow manages the impossible task of containing all the laptop internals while not being too bulky.

For power he at first used a 4 AH LiPo cell from a dead tablet with a Pimoroni LiPo power board, but since he hit problems with the Pimoroni board supplying both screen and Pi he’s switched to an off-the-shelf power bank. Unusually this laptop also has built-in audio, using another Pimoroni product, their speaker pHAT.

Where this laptop has a flaw though is in the display hinges. He has plans for a beautifully made 3D printed hinge, but for now he’s using a piece of tape, which though functional does not add to the aesthetic. When we saw it in Cambridge the keyboard was fitting more snugly than it does in the photos on his write-up, so perhaps he’s fixed some of its issues. Despite the in-progress hinge it’s a very usable little Pi laptop, and though (Hint, [Archie]!) he hasn’t yet published the design files for it, we’re sure when he does we’ll see other people building the same machine. They won’t be quite as exclusive as [Archie]’s model though, while he was in Cambridge he managed to get it signed by [Eben Upton], founder of the Raspberry Pi Foundation and judge for the 2017 Hackaday Prize.

We recently showed you a Pi laptop build in a cigar box that was useful in its detailing of the various modules required, but in the past we’ve shown you another one using the official touch screen, a lovely one in the style of a Psion palmtop, and vertically bulky yet small-footprint one, and another that keeps its presence hidden.

A tip of the hat to Norwich Hackspace.

Filed under: Raspberry Pi
Categories: Hack-a-Day

Another 74XX Series CPU

5 hours 32 min ago

[Jack Eisenmann] is no stranger to building impressive DIY CPU’s on vast stretches of breadboard. This time [Jack] has done away with the seventeen breadboards he used in his last 8-bit computer and instead has gone a step further and designed a set of generously utilised PCB’s for the CPU. The result is the DUO Enterprise.

The CPU design is based around an 8-bit data bus and a 24-bit address bus. As usual, a minimal yet carefully chosen instruction set allows [Jack] to do all the heavy lifting in software as part of the compiler and operating system he is working on. There is no sign of a display yet, instead the computer communicates via a dumb terminal. We love the aluminum foil for shielding! Check out the video, below, to see what we mean.

Over the years, we have seen many of [Jack]’s other CPU builds featured on Hackaday. One of his first designs was a 4-bit CPU that could play many games on a LED matrix.Later he did a much more impressive 8-bit CPU along with analog video output and an OS ofcourse. It could even play pong. He even built a Single Instruction Set Computer (SISC).

His final goal with DUO Enterprise is to allow anyone to utilise its computing power by submitting programs and calculations. Heads up [Jack], our neural net needs training soon.

Filed under: classic hacks, computer hacks
Categories: Hack-a-Day

Vintage Transistor powers QRP Transmitter

8 hours 32 min ago

[Pete Juliano, N6QW] built a 20 M QRP CW transmitter using just a handful of parts. That in itself will not raise any eyebrows, until you find that he built it using one of the very first RF transistors manufactured all the way back in 1955. That’s from before the time most of us were born and not many years after the invention of the transistor in late 1947.

QRP in HAM-speak technically stands for a request to “reduce power” or an offer of “should I reduce power” when appended with a question mark. A QRP transmitter is designed to transmit at really low powers. The accepted upper power limit for QRP transmitters is 5 W, at least for modes like CW using FM or AM modulation. [Pete]’s interest was piqued when he read about a 10 mW 10 M QRP transmitter design in a vintage Radio magazine from the late ’50’s and decided to replicate it. We aren’t sure, but it appears he had a Philco SB-100 RF transistor lying around in his parts bin. The SB-100 was one of the first surface-barrier transistors and could output 10 mW at frequencies up to 30MHz.

[Pete]’s rig was originally putting out 0.4 mW with a 3 V supply, and oscillating at 14.060 MHz in the 20 M band. The design appears to be a simple Colpitts oscillator with just a few parts assembled in dead-bug style on a piece of copper clad laminate. After adding an output transformer, he managed to increase the power output to about 25 mW. Check out [Pete N6QW] sending out a CQ shout out from his QRP transmitter in the video after the break.

If this gets you interested in Amateur Radio, but you are mic-shy, then [Dan Maloney] has some options for you in Shut Up and Say Something: Amateur Radio Digital Modes.

SBF image via Historianbuff CC-BY-SA 3.0, Public Domain
[via Dangerous Prototypes]

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

3G to WiFi Bridge Brings the Internet

11 hours 32 min ago

[Afonso]’s 77-year-old grandmother lives in a pretty remote location, with only AM/FM radio reception and an occasionally failing landline connecting her to the rest of the world. The nearest 3G cell tower is seven kilometers away and unreachable with a cell phone. But [Afonso] was determined to get her up and running with video chats to distant relatives. The solution to hook granny into the global hive mind? Build a custom antenna to reach the tower and bridge it over to local WiFi using a Raspberry Pi.

The first step in the plan was to make sure that the 3G long-shot worked, so [Afonso] prototyped a fancy antenna, linked above, and hacked on a connector to fit it to a Huawei CRC-9 radio modem. This got him a working data connection, and it sends a decent 4-6 Mbps, enough to warrant investing in some better gear later. Proof of concept, right?

On the bridging front, he literally burned through a WR703N router before slapping a Raspberry Pi into a waterproof box with all of the various radios. The rest was a matter of configuration files, getting iptables to forward the 3G radio’s PPP payloads over to the WiFi, and so on. Of course, he wants to remotely administer the box for her, so he left a permanent SSH backdoor open for administration. Others of you running remote Raspberry Pis should check this out.

We think it’s awesome when hackers take connectivity into their own hands. We’ve seen many similar feats with WiFi, and indeed [Afonso] had previously gone down that route with a phased array of 24 dBi dishes. In the end, the relatively simple 3G Pi-and-Yagi combo won out.

Part two of the project, teaching his grandmother to use an Android phone, is already underway. [Afonso] reports that after running for two weeks, she already has an Instagram account. We call that a success!

Filed under: Raspberry Pi, wireless hacks
Categories: Hack-a-Day

2017: The Year of the Dishwasher Security Patch

14 hours 32 min ago

As if Windows Update wasn’t bad enough, one has to deal with a plethora of attention-hungry programs and utilities all begging for a continual stream of patches from the Internet. It’s exhausting, but unfortunately also par for the course. Many of these updates are to close security vulnerabilities that could otherwise expose your computer to undesirables. The Internet of Things will only expand the amount of hardware and software you need to keep updated and protected on a daily basis. Now, it’s your dishwasher that’s under attack.

The Register reports that Jens Regel discovered the bug in a Miele dishwasher with a webserver. It’s a basic directory traversal attack that can net the intruder the shadow password file. Armed with this, it’s simple to take over the embedded Linux system and wreak havoc on your local network.

It’s not particularly surprising – we’ve talked about IoT security and its pitfalls before. The problem is, a dishwasher is not a computer. Unlike Microsoft, or Google, or even the people behind VLC, Miele don’t have infrastructure in place to push out an update to dishwashers worldwide. This means that as it stands, your only real solutions are to either disconnect the dishwasher from your network, or lock it behind a highly restrictive firewall. Both are likely to impede functionality. Of course, as always, many will ask why a dishwasher needs to be connected to the Internet at all. Why indeed.

Filed under: news
Categories: Hack-a-Day

The Midwest RepRap Festival Spectacular

16 hours 2 min ago

Every year, nestled between a swine auction and beef auction at the fairgrounds in Goshen, Indiana, the world’s greatest 3D-printing meetup happens. The Midwest RepRap Festival draws the greatest minds in 3D printing from around the world, with teams flying in from Prague, Oxford, and Hong Kong. This year was bigger than any other year. Over 1,000 people ventured forth into the sticks to attend this awesome festival dedicated to DIY printers.

What did we see this year? The PartDaddy, SeeMeCNC’s 18-foot-tall delta printer made an appearance. We saw a new extruder from E3D, and an announcement that Open Source filaments will soon be a reality. True color printing with a five filament CMYKW system is weird and cool. DIY resin printers using laser diodes and galvos are now a thing. An Easy Break Oven isn’t broken. Printers with an infinite build volume now exist, and it skirts around a MakerBot patent, too.

There was more to see at MRRF than a single weekend would allow. [Jason Kridner] from BeagleBone was there talking about the latest in fancy single-chip Linux computers. Hackerspaces were there talking about their coolest builds and doing the calculations necessary to strap model rocket engines to 3D printed rockets. A few local colleges sent teams out to talk about their efforts to bring additive manufacturing to their programs. YouTube personalities were there. Check out the rest of the goodies we saw below.

Panoramas while in full swing

Click to embiggen

Double the volume of your $200 Monoprice printer

This weekend, [Bill Steele] brought out his unnamed infinite build volume printer. This was, by far, the most mind-bending innovation we saw at MRRF. This printer was just an experiment, though. [Bill]’s main gig is Polar3D, manufacturers of a printer that isn’t cartesian and isn’t a delta.

[Bill] saw the now-famous $200 Monoprice MP Select Mini printer and figured this was good platform for experimentation. He removed the bed, slapped a gear on the Y-axis motor, and bought a circular mirror at the local craft shop. The result is a Monoprice printer modded to a polar-coordinate printer. It works, and it doubles the build volume of this printer.

The modification to turn the Monoprice printer into a polar printer is actually pretty simple – just a few 3D printed parts are necessary to support the bed, and the drive gear on the bed could probably be a printed part. The hard part is converting normal cartesian G-code into polar G-code, but thanks to the Polar3D printer, [Bill] already has those scripts handy.

The conversion process is relatively simple, and [Bill] says he could sell a kit for about $100. For a $200 printer, that’s not very economical, but it would make a great DIY project.

Squishier Ninjaflex

If you want a part that’s squishy, you’re probably going to pick up a spool of Ninjaflex. Ninjaflex and other TPE and TPU filaments aren’t that squishy, though, which means there’s a market for a Stretch Armstrong of printable plastics. It was at MRRF, and it’s called X60

From a simple grip strength crush test, the X60 filament is much more compressable. It’s much more satisfying to crush than Ninjaflex, and is what you would expect from a truly flexible filament. The only problem with X60 is printing it. Ninjaflex isn’t easy to print with some extruders, and that’s doubly so with X60. Apparently, you can only print X60 with the Flexion extruder. It’s interesting and squishy, though.

Wubba Lubba Dub Dub

Printed Solid brought out their six foot tall Rick from Rick and Morty. Grass tastes bad.

MRRF has a flea market

Last year we noticed something new at MRRF. People were selling spare parts. It was inevitable that a flea market or swap meet would form spontaneously at a 3D printer convention. There were some great deals here, including a The MP Mini Select for $150, a MendelMax 2.0 for $200, an old i2 for $75, and a few quadcopters. If you’re looking to pick up a good printer cheap, MRRF is a great place to do it. Here are the pics:

The second tallest printer at MRRF

[Joe Spanier] from River City Labs brought a monstrous printer to MRRF. The bed isn’t that big, but the vertical build volume is where this thing really shines. This printer can print something seven or eight feet tall. The printer is made out of MDF, with a huge 2 mm nozzle squirting a lot of filament out at a time. The big print here is [mechg]’s single-perimeter rocket plane, scaled a bit too much in the Z-axis.

Can’t wait until next year

MRRF has nearly doubled in size over last year. The Midwest RepRap festival is quickly becoming the defining event for desktop 3D printing and we’re expecting things to be even bigger. MRRF has outgrown its venue, but don’t worry – the Elkhart Country Fairgrounds has much bigger buildings that are available to rent.

MRRF 17 was great, and next year will be even better. We’ll see you there.

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

Retrotechtacular: Stereo Records

17 hours 31 min ago

The 20th century saw some amazing technological developments. We went from airplanes to the moon. We went from slide rules to digital computers. Crank telephones to cell phones. But two of the most amazing feats of that era were ones that non-technical people probably hardly think about. The transformation of radio and TV from mono and black and white, to stereo and color. What was interesting about both of these is that engineers managed to find a way to push the new better result into the same form as the old version and — this is the amazing part — do it in such a way that the old technology still worked. Maybe it is the rate that new technology moves today, but we aren’t doing that today. Digital TV required all-new everything: transmitters, receivers, frequencies, and recording gear. Good luck trying to play the latest video game on your 25-year-old PC.

It is hard to remember when stores were full of all sorts of audio and video media. We’ve noticed that all forms of media are starting to vanish. Everything audio and video are all streamed or downloaded these days. Records, 8-tracks, cassettes, and even CDs and DVDs are vanishing. However, vinyl records have made a come back in the last few years for their novelty or nostalgic value.

Audio recording on wax, foil, or vinyl was more or less the same process perfected by [Thomas Edison] (or, perhaps, people who worked for him) back in 1877 although the flat records we think of didn’t appear until around 1890.

The principle is simple. Air pressure from sound cuts a groove into the recording medium. A piezoelectric stylus (or later, a stylus with a dynamic element) traced the groove and reproduced the same sound. Amplify it, and the phonograph is in business. You might enjoy the gramophone [SynthDan1] restored in the video below.


By the 1950s, the hackers of their day were building or buying “hi-fi” equipment, gear that sounded better than the poor-quality audio spewing out of record players and AM radios of the day. Eventually, companies would roll out stereo recordings. But the records didn’t look any different, and they would still play on a standard (mono) record player. How is that possible? No, it isn’t two separate records like the vintage player at the top of this post found in the Museum of Technology in Paris.

We could explain it, but it is more fun to let [Bob Banks] from RCA explain it in this vintage advertisement.

The Real Story

Pretty impressive special effects for the time. [Bob] did oversimplify a few things, though. First, the groove can have a vertical component and a horizontal component. But the resolution on the vertical isn’t nearly as good, so that means one channel would be disadvantaged. Instead, the two tracks in the single groove are spun 45 degrees so that each channel has some horizontal and some vertical component.

[Bob] wants you to think RCA invented this, although he never actually says that flat out. In fact, [Alan Blumlein] of EMI patented the scheme back in 1931. The first commercial stereo records, which were not from RCA either, would not appear until 1957.

Because of how the groove was rotated, the movement of the stylus horizontally was the combination of the left and right tracks — the same as the mono signal. The vertical motion carried the difference: the left channel minus the right channel, or L-R.

That’s how a mono record could play back normally on a stereo player. The horizontal motion on the track will reproduce the same sound on both channels. Conversely, a mono stylus reading a stereo track would only pick up the horizontal part of the track and play both channels together. Unfortunately, many mono players didn’t move up and down very well and could wear a stereo record, so users learned not to play stereo records on mono players, even though it would work. Of course, that assumes you have the same-sized grooves. Older records had wider grooves and wider needles.

If you want to see how a stereo cutter works, check out [EpicenterBryan’s] video below.


In a market where Elvis Presley was still selling 78 RPM records because his fans couldn’t afford new record players, this compatibility was very important. We imagine [Alan Blumlein] would be horrified to see how we routinely tell everyone to throw away their tapes for CDs and their CDs for digital music. TV was the same. Making a signal with color that black and white sets could still receive was quite the marvel (and a topic for a future Retrotechtacular). The idea of making everyone throw out their sets for new ones or buy government-subsidized converters would have been poorly received, indeed.

We can’t help but wonder if we are doing all we can on compatibility. Do we really have to trash operating systems and CPUs every few years? Do we really need to double the memory in our phones every time our contracts run out? Or is it a clever planned obsolescence ploy? As people who create things, how are we doing on compatibility? We’ll see how history judges.

Featured image by [ParameterBond], Public Domain

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

Next Weekend: The Vintage Computer Festival East

18 hours 32 min ago

Next weekend is the Vintage Computer Festival East in Wall, New Jersey. We’re going, and you should be there too.

The VCF East is the largest gathering of retrocomputing aficionados on the east coast. It’s three days of talks, exhibits, a flea market, and a pow-wow of the greatest minds buried under obsolete technology. No VCF is complete without a few talks, and this year is shaping up to be great. Keynotes will include [Bjarne Stroustrup], designer / implementor / inventor of C++. Computer historian [Bill Degnan] will give a review of 40 years of ‘appliance computers’, and [Tom Perera], Ph.D. will be giving a talk on the Enigma machine.

The exhibits at VCF are always the star of the show, and this year is no different. Highlights include mechanical computers, the finest from Silicon Graphics, and a version of Unix published by Microsoft. The individual exhibits are always great; last year the world’s first digital camera made an appearance. If you’re in the area, this isn’t an event to miss. VCF is going down at InfoAge, a science center at the former Camp Evans — a military installation that is best described as, ‘DARPA before World War II’.

Hackaday is proud to once again sponsor VCF East. This has been going on for a couple of years now and our Art Director, [Joe Kim] has created some incredible art as part of the sponsorship. Click on the thumbnail of this year’s art to embiggen. The VCF West art from last year is a stunning take on the Macintosh and last year’s VCF East art reflected the retro hackathon we sponsored.

Filed under: cons, Original Art
Categories: Hack-a-Day

Russian Hackers Domain Fronting

Tue, 2017-03-28 23:01

FireEye just put out a report on catching the Russian hacker group “Advanced Persistent Threat 29” (APT29, for lack of a better code name) using the meek plugin for TOR to hide their traffic. If you’re using meek with, you’ll find it’s been shut down. If all of this is gibberish to you, read on for a breakdown.

meek is a clever piece of software. Imagine that you wanted to communicate with the Tor anonymizing network, but that you didn’t want anyone to know that you were. Maybe you live in a country where a firewall prevents you from accessing the full Web, and blocks Tor entry nodes as part of their Great Firewall. You’d want to send traffic somewhere innocuous first, and then bounce it over to Tor, in order to communicate freely.

That’s what meek does, but it goes one step further. The reflector server is hosted using the same content-delivery network (CDN) as a popular service, say Google’s search engine. The CDN has an IP address, like every other computer on the Internet, but it delivers content for any of the various services it hosts. Traffic to the CDN, encrypted with TLS, looks the same whether it’s going to the meek reflector or to Google, so nobody on the outside can tell whether it is a search query or packets destined for Tor. Inside the CDN, it’s unencrypted and passed along to the reflector.

Anyway, meek was invented to help bring the uncensored Internet to people who live in oppressive regimes, and now cybersecurity researchers have observed it being used by Russian state hackers to hide their tracks. Sigh. Technology doesn’t know which side it’s on — the same backdoor that the FBI wants to plant in all our communications can be used by the mafia just as easily. Plugins that are meant to bring people freedom of speech can just as easily be used to hide the actions of nation-state hackers.

What a strange world we live in.

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

Source Parts on TaoBao: An Insider’s Guide

Tue, 2017-03-28 22:01

For hardware aficionados and Makers, trips to Shenzhen’s Huaqiangbei have become something of a pilgrimage. While Huaqiangbei is a tremendous and still active resource, increasingly both Chinese and foreign hardware developers do their sourcing for components on TaoBao. The selection is vastly greater and with delivery times rarely over 48 hours and frequently under 24 hours for local purchases it fits in nicely with the high-speed pace of Shenzhen’s hardware ecosystem.

For overseas buyers, while the cost of Taobao is comparable to, or slightly less than AliExpress and Chinese online stores, the selection is again, many, many times the size. Learning how to effectively source parts from Taobao will be both entertaining and empowering.

XKCD: Up Goer Five Understanding How Chinese Works is Helpful

You can find nearly anything on TaoBao, if you know the Chinese name for it. This doesn’t mean you need to speak Chinese, but you should understand how it works. While the site can be navigated using Google Translate, it can’t accept English language searches. Figuring out what an object or part is called in Chinese is therefore the first and largest challenge. Once you find that string of characters you don’t need to be able to read it any more than any other snippet of code needs to be human readable in order to be manipulated. So long as you know roughly what the code represents that’s all that you need.

In Bunnie Huang’s Essential Guide to Electronics in Shenzhen (yes, it is (absolutely essential), Bunnie compares Chinese to XKCD’s Up Goer Five. This installment of the comic uses “only the ten hundred words people use the most often” to explain all the parts of a rocket. It’s a very accurate analogy, and once non-Chinese speakers grasp this they are able to more accurately define their search terms when sourcing online. A few thousand words are used to describe a huge number of components. Often in a pretty intuitive way if you break it down.

A 电脑 (Diànnǎo), directly translates as “Electric Brain” or a computer in English. While most Chinese characters have diverged so far from their origins to be unrecognizable — 电 (Diàn) or “electric” is one you’ll see a lot. This character is a representation of a cloud with a lightning bolt going to ground. Likewise, a 手机 Shǒujī or “Hand Machine” is a mobile phone, and 手 still looks a bit like fingers on a hand.

If you keep this structure in mind — that Chinese part names are rarely one dedicated word, and more of a semi-intuitive set of keywords — it will make finding those names much easier.

Finding Your Part by Name

Some parts you can simply use Google Translate, but sometimes it’s not specific enough or returns the wrong context for that word. In that case, it’s best to use technical websites that have been localized into Chinese as a resource.

For electronic parts the .com and .cn versions of the Mouser site are interchangeable. Mostly just the category names are translated but that can get you very close and is useful for working with Chinese engineers. You can send them the URL of the type of part you want, there is a picture and no confusion. They can do the same for English speakers but in reverse.



For mechanical parts, Misumi offers similar functionality by replacing “us” with “cn”.

becomes Refining your search

Google Translating “switch” will get you “开关” You can paste that into the TaoBao search field and get a large and somewhat random collection of mostly AC light switches. But if we make the string “开关 DPDT” things start to get more useful. When possible add the numbers for the voltage, amperage etc. required and it will get you a lot closer.

If we see something pretty close to what we want we have two options, the first is to mouse-over the product image. An orange bar will come up, it may give you the option to “找相似” or “Find Similar”. Clicking on this will bring up things that are close, but not identical to that product.

If there is no option to “Find Similar” you can copy the Chinese description into Google Translate for more useful keywords.

6只脚DPDT蓝色MINI小型SMTS-202双刀双通钮子开关 YW2-102

and Google Translate tells us the string “双刀双通钮子开关” is “Double pole double button switch”. A search using that string gets us a large number of similar switches to choose from.

Finding Your Part by Image

Taobao has a very clever search-by-image function. If you have an image of the part you want you can use that to search. It’s the little camera icon on the right hand side of the search bar.

This has a number of uses: finding the upstream distributors of products, finding unauthorized copies of products, and seeing if new Crowdfunding campaigns are based on pre-existing Chinese products.

Making Your Order

Unlike Amazon, the “Buy” button on Taobao is more an invitation to chat about buying with the store owner. There’s usually a certain amount of required conversation. Some non-Chinese speakers copy and paste a “sorry I don’t speak Chinese” boilerplate but many stores won’t fulfill an order based on this because they are concerned that miscommunication will lead to a bad review which will cost them more than the profit on the item.

This process of chatting for more than half of all orders and lack of a straightforward shopping-cart-and-buy-it process means it can be difficult for those who can’t read Chinese to make TaoBao purchases. They also don’t accept PayPal and while supposedly there is a process to accept Western credit cards I don’t know anyone who’s set it up successfully.

Fortunately, there are services that will simply take care of this on you behalf. You send them links to the products you want and for a modest fee they take care of the rest. These brokers buy the items, charge it to your PayPal or credit card, accept the packages on your behalf, consolidate them and then forward them to you. Usually, the cost of the item plus this service fee is still less than purchasing the same items through AliExpress and gives you access to a far larger selection.

Some TaoBao brokers (in no order):

When in Shenzhen, Ringy provides translation services for free over WeChat and can have the packages sent to your hotel.

  • WeChat: ringyringy
Things to Avoid

“Will it be ready by Monday”

Never ask if it will be ready by a specific date, the answer will almost always be “yes”. There’s nothing much you can do if it’s not, so they have no reason to lose the sale. So when dealing with your TaoBao broker don’t ask “Can they have it ready by Monday?”, instead ask “What day do they say it will be ready?” and you get a much more accurate answer.

In general, this pattern should be followed when sourcing in China. Ask “What colors does it come in?” before the much more problematic “can they make it in pink?”. It’s far easier to be successful when working within the supplier’s established timeline and product range then starting out with something new.

“What do you want it for?”

Never answer this question from a store owner. This means they want to know if they can substitute something else based on what imagine will suffice for your requirements. Why would a 3D printer heated bed need an expensive sheet of PEI? Acrylic should be fine. You’ll get a very nice sheet of PEI colored acrylic for a bit less than the cost of PEI but a lot more than what acrylic costs. Stick with the item as listed on the BOM, if they don’t know what it’s for there is more risk of a substitution failing immediately and a poor review.

Avoid buying anything that has not been reviewed by other buyers.

Are their fake reviews? Sure, tons of them (although it’s getting better). But they cost money for the store owners to purchase and usually there are authentic ones as well — that’s cost sunk into that listing. If a listing has no feedback, a store owner loses nothing by simply taking it down in the event that you (or the agent on your behalf) gives it a bad review.

Don’t Bargain Hunt

The “get it cheaper” part is already done with when you made your choice to use TaoBao instead of a distributor back in the West. Further attempts to save money will result in problems. Everyone on Taobao sources from the same factories, if an identical or very similar product is much cheaper there’s a reason for it. Look at the top five most popular listings for a part, the average price of those or higher is what you can expect to pay.

While there are certainly challenges to sourcing on TaoBao, for any hardware enthusiast the vast, and frequently customizable selection available make it a very useful resource and skill set to have should the need arise.

Naomi Wu is a hardware enthusiast and Shenzhen native. The above guide was compiled with the generous assistance of the Shenzhen hardware community.

Filed under: Business, Featured, how-to
Categories: Hack-a-Day

Arch Your Eyebrow at Impression Products V. Lexmark International

Tue, 2017-03-28 19:01

When it comes to recycled printer consumables, the world seems to divide sharply into those who think they’re great, and those who have had their printer or their work ruined by a badly filled cartridge containing cheaper photocopy toner, or God knows what black stuff masquerading as inkjet ink. It doesn’t matter though whether you’re a fan or a hater, a used printer cartridge is just a plastic shell with its printer-specific ancilliaries that you can do with what you want. It has performed its task the manufacturer sold it to you for and passed its point of usefulness, if you want to fill it up with aftermarket ink, well, it’s yours, so go ahead.

There is a case approaching the US Supreme Court though which promises to change all that, as well as to have ramifications well beyond the narrow world of printer cartridges. Impression Products, Inc. v. Lexmark International, Inc. pits the printer manufacturer against a small cartridge recycling company that refused to follow the rest of its industry and reach a settlement.

At issue is a clause in the shrink-wrap legal agreement small print that comes with a new Lexmark cartridge that ties a discounted price to an agreement to never offer the cartridge for resale or reuse. They have been using it for decades, and the licence is deemed to have been agreed to simply by opening the cartridge packaging. By pursuing the matter, Lexmark are trying to set a legal precedent allowing such licencing terms to accompany a physical products even when they pass out of the hands of the original purchaser who accepted the licence.

There is a whole slew of concerns to be addressed about shrink-wrap licence agreements, after all, how many Lexmark owners even realise that they’re agreeing to some legal small print when they open the box? But the concern for us lies in the consequences this case could have for the rest of the hardware world. If a precedent is set such that a piece of printer consumable hardware can have conditions still attached to it when it has passed through more than one owner, then the same could be applied to any piece of hardware. The prospect of everything you own routinely having restrictions on the right to repair or modify it raises its ugly head, further redefining “ownership” as  “They really own it”. Most of the projects we feature here at Hackaday for example would probably be prohibited were their creators to be subject to these restrictions.

We’ve covered a similar story recently, the latest twist in a long running saga over John Deere tractors. In that case though there is a written contract that the farmer buying the machine has to sign. What makes the Lexmark case so much more serious is that the contract is being applied without the purchaser being aware of its existence.

We can’t hold out much hope that the Supreme Court understand the ramifications of the case for our community, but there are other arguments within industry that might sway them against it. Let’s hope Impression Products v. Lexmark doesn’t become a case steeped in infamy.

Thanks to [Greg Kennedy] for the tip.

Lexmark sign by CCC2012 [CC0].

Filed under: Current Events, hardware, news
Categories: Hack-a-Day

“Norman, coordinate!”

Tue, 2017-03-28 16:01

If Star Trek taught us anything, it’s clearly that we’re not quite in the future yet. Case in point: androids are not supposed to be little flecks of printed circuits with wires and jacks sprouting off them. Androids are supposed to be gorgeous fembots in polyester kimonos with beehive hairdos, designed to do our bidding and controlled by flashing, beeping, serial number necklaces.

Not willing to wait till the 23rd century for this glorious day, [Peter Walsh] designed and built his own android amulet prop from the original series episode “I, Mudd.” There’s a clip below if you need a refresher on this particularly notable 1967 episode, but the gist is that the Enterprise crew is kidnapped by advanced yet simple-minded androids that can be defeated by liberal doses of illogic and overacting.

The androids’ amulets indicate when they BSOD by flashing and beeping. [Peter]’s amulet is a faithful reproduction done up in laser-cut acrylic with LEDs and a driver from a headphone. The leads for the amulet go to a small control box with a battery pack and the disappointing kind of Android, and a palmed microswitch allows you to indicate your current state of confusion.

You’ll be sure to be the hit of any con with this one, although how to make smoke come out of your head is left as an exercise for the reader. Or if you’d prefer a more sophisticated wearable from The Next Generation, check out this polished and professional communicator badge. Both the amulet and the communicator were entries in the Hackaday Sci-Fi contest.

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

Hacked IoT Switch Gains I2C Super Powers

Tue, 2017-03-28 13:00

Economies of scale and mass production bring us tons of stuff for not much money. And sometimes, that stuff is hackable. Case in point: the $5 Sonoff WiFi Smart Switch has an ESP8266 inside but the firmware isn’t very flexible. The device is equipped with the bare minimum 1 MB of SPI flash memory. Even worse, it doesn’t have the I2C ports extra pins exposed so that you can’t just connect up your own sensors and make them much more than just a switch. But that’s why we have soldering irons, right?

[Jack] fixed his, and documented the procedure. He starts off by soldering a female header to the board so that he can upload his own firmware. (Do not do this when it’s plugged into the wall, you could get electrocuted. Supply your own 3.3 V.) Next, he desolders the flash memory and replaces it with a roomy 4 MB chip, because he might want to upgrade the firmware over the air, or just run some really, really big code. So far, so good. He’s got a better version of the same thing.

But breaking out the ESP8266’s I2C pins the pins that ESPEasy uses for software-emulated I2C turns this little “switch” into something much more useful — a wall-powered IoT sensor node in a sweet little package, with a switch attached. It’s just a matter of tacking two wires onto the incredibly tiny pins of the ESP8266 package. The good news is that the I2C pins are on the edge of the package, but you’re going to want your fine-tipped iron and some magnification regardless.

That’s it. Flash in a better firmware, connect up whatever I2C devices you’d like, and you’ve got a very capable addition to your home automation family for just a few bucks. Just for completeness, here’s the warning again: this device uses a non-isolated power supply, so if the neutral in your wall isn’t neutral, you can get shocked. And stay tuned for a full-length article on transformerless power supplies, coming up!

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

Safe Cracking is [Nate’s] Latest R&D Project

Tue, 2017-03-28 10:00

We love taking on new and awesome builds, but finding that second part (the “awesome”) of each project is usually the challenge. Looks like [Nathan Seidle] is making awesome the focus of the R&D push he’s driving at Sparkfun. They just put up this safe cracking project which includes a little gamification.

The origin story of the safe itself is excellent. [Nate’s] wife picked it up on Craig’s List cheap since the previous owner had forgotten the combination. We’ve seen enough reddit/imgur threads to not care at all what’s inside of it, but we’re all about cracking the code.

The SparkX (the new rapid prototyping endeavor at Sparkfun) approach was to design an Arduino safe cracking shield. It has a motor driver for spinning the dial and can drive a servo that pulls the lever to open the door. There is a piezo buzzer to indicate success, and the board as a display header labeled but not in use, presumably to show the combination currently under test. We say “presumably” because they’re not publishing all the details until after it’s cracked, a process that will be live streamed starting Wednesday. This will keep us guessing on the use of that INA169 current sensor that plugs into the safecracking shield. There is what appears to be a reflectance sensor above the dial to keep precise track of the spinning dial.

Electrically this is what we’d expect, but mechanically we’re in love with the build. The dial and lever both have 3D printed adapters to interface with the rest of the system. The overall framework is built out of aluminum channel which is affixed to the safe with rare earth magnets — a very slick application of this gear.

The gamification of the project has to do with a pair of $100 giveaways they’re doing for the closest guess on how long it’ll take to crack (we hope it’s a fairly fast cracker) and what the actual combination may be. For now, we want to hear from you on two things. First, what is the role of that current sensor in the circuit? Second, is there a good trick for optimizing a brute force approach like this? We’ve seen mechanical peculiarities of Master locks exploited for fast cracking. But for this, we’re more interested in hearing any mathematical tricks to test likely combinations first. Sound off in the comments below

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

Casting Machine Bases in Composite Epoxy

Tue, 2017-03-28 07:00

When you’re building a machine that needs to be accurate, you need to give it a nice solid base. A good base can lend strength to the machine to ensure its motions are accurate, as well as aid in damping vibrations that would impede performance. The problem is, it can be difficult to find a material that is both stiff and strong, and also a good damper of vibrations. Steel? Very stiff, very strong, terrible damper. Rubber? Great damper, strength leaves something to be desired. [Adam Bender] wanted to something strong that also damped vibrations, so developed a composite epoxy machine base.

[Adam] first takes us through the theory, referring to a graph of common materials showing loss coefficient plotted against stiffness. Once the theory is understood, [Adam] sets out to create a composite material with the best of both worlds – combining an aluminium base for stiffness and strength, with epoxy composite as a damper. It’s here where [Adam] begins experimenting, mixing the epoxy with sand, gravel, iron oxide and dyes, trying to find a mixture that casts easily with a good surface finish and minimum porosity.

With a mixture chosen, it’s then a matter of assembling the final mould, coating with release agent, and pouring in the mixture. The final result is impressive and a testament to [Adam]’s experimental process.

We’ve seen similar builds before — like this precision CNC built with epoxy granite — but detail in the documentation here is phenomenal.

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

Cheap Smarthome Gadget(s) Hacked into Zigbee Sniffer

Tue, 2017-03-28 04:00

French hacker [akila] is building up a home automation system. In particular, he’s been working with the “SmartHome” series of gadgets made by Chinese smartphone giant, Xiaomi. First, he started off by reverse-engineering their very nicely made temperature and humidity sensor. (Original in French, hit the translate button in the lower right.) With that under his belt, he opened up the PIR motion sensor unit to discover that it has the same debugging pinouts and the same processor. Almost too easy.

For a challenge, [akila] decided it was time to implement something useful in one of these gadgets: a ZigBee sniffer so that he can tell what’s going on in the rest of his home network. He built a USB/serial programming cable to work with the NXP JN5169’s bootloader, downloaded the SDK, and rolled up his sleeves to get to work.

While trolling through the SDK, he found some interesting firmware called “JennicSniffer”. Well, that was easy. There’s a demo version of a protocol analyzer that he used. It would be cool to get this working with Wireshark, but that’s a project for another day. [Akila] got far enough with the demo analyzer to discover that the packets sent by the various devices in the home network are encrypted. That’s good news for the security-conscious out there and stands as the next open item on [akila]’s to-do list.

We don’t see as many ZigBee hacks as we’d expect, but they’ve definitely got a solid niche in home automation because of commercial offerings like Philips Hue and Wink. And of course, there’s the XBee line of wireless communications modules. We just wrote up a ZigBee hack that aims to work with the Hue system, though, so maybe times are changing?

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

[Joe Grand’s] Toothbrush Plays Music That Doesn’t Suck

Tue, 2017-03-28 02:31

It’s not too exciting that [Joe Grand] has a toothbrush that plays music inside your head. That’s actually a trick that the manufacturer pulled off. It’s that [Joe] gave his toothbrush an SD card slot for music that doesn’t suck.

The victim donor hardware for this project is a toothbrush meant for kids called Tooth Tunes. They’ve been around for years, but unless you’re a kid (or a parent of one) you’ve never heard of them. That’s because they generally play the saccharine sounds of Hannah Montana and the Jonas Brothers which make adults choose cavities over dental health. However, we’re inclined to brush the enamel right off of our teeth if we can listen to The Amp Hour, Embedded FM, or the Spark Gap while doing so. Yes, we’re advocating for a bone-conducting, podcasting toothbrush.

[Joe’s] hack starts by cracking open the neck of the brush to cut the wires going to a transducer behind the brushes (his first attempt is ugly but the final process is clean and minimal). This allows him to pull out the guts from the sealed battery compartment in the handle. In true [Grand] fashion he rolled a replacement PCB that fits in the original footprint, adding an SD card and replacing the original microcontroller with an ATtiny85. He goes the extra mile of making this hack a polished work by also designing in an On/Off controller (MAX16054) which delivers the tiny standby current needed to prevent the batteries from going flat in the medicine cabinet.

Check out his video showcasing the hack below. You don’t get an audio demo because you have to press the thing against the bones in your skull to hear it. The OEM meant for this to press against your teeth, but now we want to play with them for our own hacks. Baseball cap headphones via bone conduction? Maybe.

Filed under: digital audio hacks, musical hacks
Categories: Hack-a-Day

Getting Sparks from Water with Lord Kelvin’s Thunderstorm

Tue, 2017-03-28 01:01

In the comments to our recent article about Wimshurst machines, we saw that some hackers had never heard of them, reminding us that we all have different backgrounds and much to share. Well here’s one I’m guessing even fewer will have heard of. It’s never even shown up in a single Hackaday article, something that was also pointed out in a comment to that Wimshurst article. It is the Lord Kelvin’s Water Dropper aka Lord Kelvin’s Thunderstorm, invented in the 1860s by William Thomson, 1st Baron Kelvin, the same fellow for whom the Kelvin temperature scale is named.  It’s a device that produces a high voltage and sparks from falling drops of water.

A Brief Overview

Lord Kelvin’s Thunderstorm is build around the concept of water droplets falling through inductors. Two streams of water fall from small holes in reservoirs at the top. Those streams fall through two metal cylinders, called inductors, not making contact with them. A stream of falling water will change from a continuous stream into individual drops at some point, if it falls far enough.

The inductors are vertically positioned such that this change from continuous stream to individual drops happens as the water is falling through the inductors. To see these drops, the photo on the right, above, was taken with a fast shutter speed. Finally, the drops fall into metal cans, called receivers, at the bottom.

The receiver on the left is electrically connected to the inductor on the right, and the receiver on the right is electrically connected to the inductor on the left. You can see this in the photo above in the form of the crossing yellow and red wires.

Also, a wire is connected to each receiver and goes to either side of a spark gap. Every now and then, a spark crosses the gap. Magic. Or is it?

How It Works
  1. To begin, there has to be some excess electric charge somewhere, either positive or negative. And there usually is. Let’s say that the right receiver has a slight net negative charge. Since it’s wired to the left inductor, the left inductor also has a slight negative charge.
  2. Here is where the real magic happens. Remember that the inductor is vertically positioned where the continuous stream breaks up into drops. Since the left inductor is negatively charged, it repels negative charge in the water. The continuous water stream from the reservoir to the inductor acts like a wire and that negative charge is repelled up that stream to the reservoir. But that leaves the drops falling below the inductor with a net positive charge. And since they are individual drops, they stay positive, all the way to the left receiver below them.
  3. The left receiver is a metal can and is in electrical contact with the water in it, and so the left receiver is made positive by those positively charged drops.But the left receiver is wired to the right inductor. That means the right inductor also becomes positively charged.
  4. That right inductor also has a stream of continuous water entering it from above and drops leaving it below. Since the inductor is positively charged, it repels positive charge up the solid water stream to the reservoir above. Meanwhile, the drops leaving it are left with a net negative charge and fall into the receiver below them.
  5. If you recall from step 1, the right reservoir was the one we started with, and was slightly negative. Now, as a result of the negatively charged drops falling into it, that receiver becomes even more negative.And since that right receiver is wired to the left inductor, that makes the left inductor more negative, which repels negative charge up the left stream, while the drops below it are made positive, and fall into the left receiver, making the left receiver more positive, and so on.
  6. So the right receiver becomes more and more negative while the left receiver becomes more and more positive. But remember, the two receivers are wired up to opposite sides of a spark gap. The electrodes at the spark gap also become more and more negative and positive. That is, until the voltage across the spark gap becomes so strong that it breaks down the air between them, and a spark crosses the gap, discharging the whole thing. But of course a little net charge is left somewhere and the whole process repeats.
Fanning Drops And Electroscopes

Besides watching the sparks, there are some additional fun ways to observe this repeated charging and discharging. One such way is to watch the drops fanning out as they fall, and then suddenly falling straight again.

Why does this fanning-out happen? The drops coming out of the inductors have the opposite charge of the inductors. For example, the drops falling below the left inductor are positive, while the left inductor is negative. Note also that the bottom lip of the inductor is to one side of the drops. Since unlike-charges attract, there’s a horizontal attraction between the inductors and the drops falling below them that imparts some sideways movement to the drops.

The result is a visible fanning-out of the drops. This fanning-out gets wider and wider as the inductor becomes more and more charged. That is, until the spark occurs and discharges everything. At that time the drops fall straight down again only to start fanning out as the charge builds back up.

Another fun way of observing the charging and discharging in action is to place the terminal of an electroscope near an inductor or receiver. As the charge builds up, the electroscope leafs will spread apart. But when the spark occurs, the leafs fall back together

Going Big

Rather than have just one stream falling through each inductor, some builders use something like a shower head to have multiple streams fall through. Below is a video from science YouTube channel, Veritasium, showing a large and very sci-fi looking Lord Kelvin water dropper that uses shower heads.

It also has a pump to keep the water flowing continuously. You might wonder what would happen if you did use a pump, since you’d be electrically connecting the two receivers. To avoid that, the receivers are just meshes through which the water drops fall. As the drops falls through, the mesh takes their charge. So I guess you can say these receivers receive the charge but not the water.

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

MRRF 17: A Working MakerBot Cupcake

Mon, 2017-03-27 23:30

The Midwest RepRap Festival is the best place to go if you want to see the latest in desktop 3D printing. This weekend, we saw full-color 3D printers, a printer with an infinite build volume, new extruders, a fantastic development in the pursuit of Open Source filament, and a whole bunch of D-bots. If you want the bleeding edge in 3D printing, you’re going to Goshen, Indiana.

Of course, it wasn’t always like this. In 2009, MakerBot released the Cupcake, a tiny printer that ushered in the era of democratized 3D printing. The Cupcake was a primitive machine, but it existed, it was open source, and it was cheap – under $500 if you bought it at the right time. This was the printer that brought customized plastic parts to the masses, and even today no hackerspace is complete without an unused Cupcake or Thing-O-Matic sitting in the corner.

The MakerBot Cupcake has not aged well. This should be expected for a technology that is advancing as quickly as 3D printing, but today it’s rare to see a working first generation MakerBot. Not only was the Cupcake limited by the technology available to hackers in 2009, there are some pretty poor design choices in these printers. There’s a reason that old plywood MakerBot in your hackerspace isn’t used anymore – it’s probably broken.

This year at MRRF, [Ryan Branch] of River City Labs brought out his space’s MakerBot Cupcake, serial number 1515 of 2,625 total Cupcakes ever made. He got his Cupcake to print a test cube. If you’re at all familiar with the Cupcake, yes, this is a hack. It’s a miracle these things ever worked in the first place.

This is the Cupcake in all her glory. This is where the revolution in consumer 3D printing started. This is a Gordian knot of belts and pullies, RS485 going through RJ45 connectors, huge stepper drivers, and an acrylic extruder that hasn’t yet cracked. This is a rare machine, but not because MakerBot made less than three thousand of them. There’s not much dust on it, the nichrome wire hotend still works, and all the electronics work.

Seeing this Cupcake in action was one of the highlights of my weekend at MRRF. I have seen a not insignificant fraction of all Cupcakes ever made (p > 0.05), and not a single one of them were operational. This is the first time I’ve ever seen one working. Was it working well? No, but that’s not the point. It’s the 3D printing equivalent of retrocomputing, and it’s glorious.

Over the course of the weekend, [Ryan] was able to get his Cupcake working for one print – a small test cube. How did this test cube turn out? You be the judge:

In short, this is a terrible print. This is what we had back in the day, kids.

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

Low Background Steel — So Hot Right Now

Mon, 2017-03-27 22:00

The nuclear age changed steel, and for decades we had to pay the price for it. The first tests of the atomic bomb were a milestone in many ways, and have left a mark in history and in the surface of the Earth. The level of background radiation in the air increased, and this had an effect on the production of steel, so that steel produced since 1945 has had elevated levels of radioactivity. This can be a problem for sensitive instruments, so there was a demand for steel called low background steel, which was made before the trinity tests.

The Bessemer process pumps air through the iron to remove impurities.

The production of steel is done with the Bessemer process, which takes the molten pig iron and blasts air through it. By pumping air through the steel, the oxygen reacts with impurities and oxidizes, and the impurities are drawn out either as gas or slag, which is then skimmed off. The problem is that the atmospheric air has radioactive impurities of its own, which are deposited into the steel, yielding a slightly radioactive material. Since the late 1960s steel production uses a slightly modified technique called the BOS, or Basic Oxygen Steelmaking, in which pure oxygen is pumped through the iron. This is better, but radioactive material can still slip through. In particular, we’re interested in cobalt, which dissolves very easily in steel, so it isn’t as affected by the Bessemer or BOS methods. Sometimes cobalt is intentionally added to steel, though not the radioactive isotope, and only for very specialized purposes.

Recycling is another reason that modern steel stays radioactive. We’ve been great about recycling steel, but the downside is that some of those impurities stick around.

Why Do We Need Low Background Steel?

Imagine you have a sensor that needs to be extremely sensitive to low levels of radiation. This could be Geiger counters, medical devices, or vehicles destined for space exploration. If they have a container that is slightly radioactive it creates an unacceptable noise floor. That’s where Low Background Steel comes in.

A person is placed into a low background steel container with sensitive equipment to measure the radioactivity of the body, which may be near the background level. Photo from

So where do you get steel, which is a man-made material, that was made before 1945? Primarily from the ocean, in sunken ships from WWII. They weren’t exposed to the atomic age air when they were made, and haven’t been recycled and mixed with newer radioactive steel. We literally cut the ships apart underwater, scrape off the barnacles, and reuse the steel.

Fortunately, this is a problem that’s going away on its own, so the headline is really only appropriate as a great reference to a popular movie. After 1975, testing moved underground, reducing, but not eliminating, the amount of radiation pumped into the air. Since various treaties ending the testing of nuclear weapons, and thanks to the short half-life of some of the radioactive isotopes, the background radiation in the air has been decreasing. Cobalt-60 has a half-life of 5.26 years, which means that steel is getting less and less radioactive on its own (Cobalt-60 from 1945 would now be at .008% of original levels). The newer BOS technique exposes the steel to fewer impurities from the air, too. Eventually the need for special low background steel will be just a memory.

Oddly enough, steel isn’t the only thing that we’ve dragged from the bottom of the ocean. Ancient Roman lead has also had a part in modern sensing.

Filed under: Hackaday Columns, History, Interest
Categories: Hack-a-Day