Stallman’s One Mistake

We all owe [Richard Stallman] a large debt for his contributions to computing. With a career that began in MIT’s AI lab, [Stallman] was there for the creation of some of the most cutting edge technology of the time. He was there for some of the earliest Lisp machines, the birth of the Internet, and was a necessary contributor for Emacs, GCC, and was foundational in the creation of GPL, the license that made a toy OS from a Finnish CS student the most popular operating system on the planet. It’s not an exaggeration to say that without [Stallman], open source software wouldn’t exist.

Linux, Apache, PHP, Blender, Wikipedia and MySQL simply wouldn’t exist without open and permissive licenses, and we are all richer for [Stallman]’s insight that software should be free. Hardware, on the other hand, isn’t. Perhaps it was just a function of the time [Stallman] fomented his views, but until very recently open hardware has been a kludge of different licenses for different aspects of the design. Even in the most open devices, firmware uses GPLv3, hardware documentation uses the CERN license, and Creative Commons is sprinkled about various assets.

If [Stallman] made one mistake, it was his inability to anticipate everything would happen in hardware eventually. The first battle on this front was the Tivoization of hardware a decade ago, leading to the creation of GPLv3. Still, this license does not cover hardware, leading to an interesting thought experiment: what would it take to build a completely open source computer? Is it even possible?

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The Unreasonable Effectiveness of Adhesive Tape

No doubt many of you have spent a happy Christmas tearing away layers of wrapping paper to expose some new gadget. But did you stop to spare a thought for the “sticky-back plastic” holding your precious gift paper together?

There are a crazy number of adhesive tapes available, and in this article I’d like to discuss a few of the ones I’ve found useful in my lab, and their sometimes surprising applications. I’d be interested in your own favorite tapes and adhesives too, so please comment below!

But first, I’d like to start with the tapes that I don’t use. Normal cellulose tape, while useful outside the lab, is less than ideally suited to most lab applications. The same goes for vinyl-based insulating tapes, which I find have a tendency to fall off leaving a messy sticky residue. When insulation is necessary, heatshrink seems to serve better.

The one tape I have in my lab which is similar to common cellulose tape however is Scotch Magic Tape. Scotch Magic tape, made from a cellulose acetate, and has a number of surprising properties. It’s often favored because of it’s matte finish. It can easily be written on and when taped to paper appears completely transparent. It’s also easy to tear/shape and remove. But for my purposes I’m more interested in it’s scientific applications.

Here’s a neat trick you can try at home. Take a roll of tape (I’ve tried this with Scotch Magic tape but other tapes may work too) to a dark room. Now start unrolling the tape and look at interface where the tape leaves the rest of the roll. You should see a dim blue illumination. The effect is quite striking and rather surprising. It’s called triboluminescence and has been observed since the 1950s in tapes and far earlier in other materials (even sugar when scraped in a dark room will apparently illuminate). The mechanism, however, is poorly understood.

It was perhaps this strange effect that led researchers to try unrolling tape in a vacuum. In 1953 a group of Russian researchers attempted this and bizarrely enough, were able to generate X-rays. Their results were unfortunately forgotten for many years, but were replicated in 2008 and even used to X-ray a researcher’s finger! As usual Ben Krasnow has an awesome video on the topic:

In my lab however I mostly use Scotch tape to remove surface layers. In certain experiments it’s valuable to have an atomically flat surface. Both Mica and HOPG (a kind of graphite) are composed of atomically flat layers. Scotch tape can be used to remove the upper layers leaving a clean flat surface for experimentation.

The mechanical exfoliation of Graphene

Researchers have also modified this technique to produce graphene. Graphene is composed of single carbon layers and has a number of amazing properties, highly conductive, incredibly strong, and transparent. For years producing small quantities of graphene provided difficult. But in 2004 a simple method was developed at the University of Manchester using nothing but bulk ordered graphite (HOPG) and a little Scotch tape. When repeatedly pressed between the Scotch tape, the Graphite layers can be separated until eventually only a signal layer of graphene remains.

Using Kapton to maskout traces via Dangerous Prototypes



The other non-conductive tape I use regularly in my lab is of course Kapton tape. While Kapton is a Dupoint brand name, it’s basically a polyimide film tape which is thermally stable up to 400 degrees C. This makes it ideal for work holding in electronics (or masking out pins) when soldering. You can also use it for insulating (though it’s inadvisable for production applications). Typically polyimide tape is available under a number of dubious synonyms (one example is Kaptan) from a variety of Chinese suppliers at low cost.


Carbon tape is conductive in all axes. This means it you can create a electrical connection by simply taping to your devices. It’s resistance however is somewhat high. I’ve most commonly come across this when using electron microscopes. Carbon tape is used both to keep a sample in place and create an electrical connection between the sample and the sample mount.

Carbon tape, applied to a SEM mount.

Other conducting tapes are available with lower resistance, creating a electrical connection without soldering is valuable in a number of situations. Particularly when heat might damage the device. One example of this is piezoelectric materials. Not only does solder often bond poorly to ceramic materials, but it may also depole the material removing its piezoelectric properties. I tend to use conductive epoxies in these situations, but conductive tapes appear to be an attractive option.

Aluminum tape is commonly used for (heat) insulation in homes. It’s therefore very cheap and easily available. As well as conducting heat aluminum tape of course also conducts electricity. Around the lab this can be pretty handy. While the adhesive is not conductive, making it less attractive for connection parts, I’ve found aluminum tape great of sealing up holes in shielded enclosures. It also makes a great accompaniment to aluminum foil which is used to provide ad-hoc shielding in many scientific environments. Copper tape is also easily obtained, though slightly more expensive.

Z tape under a microscope

A much less common, but far cooler conductive tape is so called Z tape. This tape is composed of regular double-sided tape impregnated with spaced conductors. The result is a tape that conducts in only one direction (from the top to the bottom). This makes it similar in structure to a zebra strip, commonly used to connect LCDs. Z tape is unfortunately pretty expensive, a short 100mm strip can cost 5 dollars. What exactly 3M had in mind when creating Z tape is unclear. But it can be used for repairing FPC connectors on LCDs or in other situations where soldering is impractical.

One of the more awesome applications is Jie and Bunnie’s circuit sticker project. The kits are designed to allow kids to assemble circuits simply by sticking components together. Z tape is ideal for this, as it allows multiple connections to be made using the same piece to tape.

I couldn’t write an article on tape without mentioning the somewhat apocryphal “Invisible Electrostatic Wall” incident. A report at the 17th Annual EOS/ESD Symposium describes a “force field” like wall that appeared during the production of polypropylene film. While the story seems slightly dubious, it reminds us of the surprising applications and utility of tapes.

Next time you’re sending off a package or ripping open a package, spare a thought for the humble tape that holds it together.

The Death of Surplus

I thought the surplus electronics market in Dallas was a byproduct of local manufacturing, after all we have some heavy hitters in our back yard: Texas Instruments, Maxim (Dallas Semiconductor), ST Micro (at one time), Diodes Incorporated. If we widen our radius to include Austin (3 hours down the road) we can make a much more impressive list by including: National Instruments, Freescale Semiconductor, better yet I’ll just insert the graphic I’m pulling data from right here:

Texas Electronics Map Source:

Granted, not all of these are companies that manufacture silicon, or even have manufacturing facilities here in Texas. That doesn’t necessarily matter for surplus to exist. Back to my point of where surplus originated. While I wasn’t completely wrong (these companies certainly have helped contribute to the surplus electronics market) the beginnings of surplus storefronts date back to World War II. Did anyone see that coming? Neither did I. However it does make sense, the US government would have had a large stock of “stuff” to get rid of at the end of the war.

Enter the sale of government surplus all over the nation, usually near air force bases. So this is how the more generalized concept of a surplus shop came to be in existence; mix in the domestic manufacturing of electronics in the 1970’s and we have electronics surplus shops aplenty.

My First Hand Experience

I didn’t really appreciate how valuable my local electronics shop was until watching Beers in Bunnie’s Workshop – Workshop Video #36. If you haven’t seen the video you only need to know that [Ian] of Dangerous Prototypes and [bunnie] of Andrew [bunnie] Huang are standing in [bunnie]s work-space in Singapore drinking beer and talking about the lab that is [bunnie]s life. You with me now? Okay, there is a point in the video where the two discuss the ability to run down the street and buy a connector as something only available in Singapore or Shenzhen. Let me briefly pause here to clarify that I’m not comparing my local electronics shop to the Shenzhen market or Sim Lim Tower in Singapore, only stating that I too can hold parts in-hand before purchasing them. I’m also not [brandon] of Dangerous Prototypes or Andrew [brandon] Huang, clearly.

I do however have an electronics selection at my disposal that is unmatched until you get to the west coast shops. I went on a bit of an adventure with the owner [Jim Tanner] of my local shop [Tanner Electronics] to take some pictures of the retail floor and a few behind the scenes (warehouse) shots that you can check out after the break.

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Video Standards Are More Than Video Signals

The number of hours we spend staring at screens is probably best unknown, but how about the technology that makes up the video on the screen? We’ve all seen a reel-to-reel projector on TV or in a movie or maybe you’re old enough to have owned one, surely some of you still have one tucked away real nice. Whether you had the pleasure of operating a projector or just watched it happen in the movies the concept is pretty straight forward. A long piece of film which contains many individual frames pass in front of a high intensity lamp while the shutter hides the film movement from our eyes and our brain draws in the imaginary motion from frame to frame. Staring at a Blu-ray player won’t offer the same intuition, while we won’t get into what must the painful detail of decoding video from a Blu-ray Disc we will look into a few video standards, and how we hack them.

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Hacklet 84 – Alarm Clocks

The stereotypical hardware hacker is a creature of the night. Some of us do our best work in the wee hours. The unfortunate side effect of this is that we have a hard time getting up in the morning. Sometimes life demands a hacker be up-and-at-em before noon though. In these cases, the only solution is an alarm clock. This week’s Hacklet features some of the best alarm clock projects on!

mercyWe start with [hberg32] and Merciless Pi Alarm Clock. Merciless is a good name for this Raspberry Pi based clock. We have to say it’s quite snazzy with its laser cut case and large seven segment LED face. When the alarm goes off though, this Pi bites back.

Titanium drivers powered by a 20 watt amplifier will wake even the heaviest sleepers. If that’s not enough, [hberg32] added a bed shaker to vibrate you out of the sack. The snooze button only works 3 times, after that you can press all you want, the music will still play. As if that wasn’t enough, this clock even has a pressure sensor. If you get back in bed, the alarm starts up again. Truly fitting of the name “merciless”.

irss[Ceady] took the kinder, gentler route with Integrated Room Sunrise Simulator. This alarm clock simulates dawn, gently waking the user up. A Lutron Maestro series wireless dimmer allows the sunrise simulator to slowly increase the room’s light level over a period of 10 minutes, allowing [Ceady] to wake up silently.

The clock itself uses an ATmega168 for control. [Ceady] spent a considerable amount of time testing out different methods of creating a seven segment LED display. When casting with cornstarch and resin didn’t do the trick, he went to commercial LED diffuser film from Inventables. The film proved to be just what he was looking for.

chumby2Next up is [Spiros Papadimitriou] with DIY Chumby-lite. Taking inspiration from [Bunnie Huang] and the Chumby project, [Spiros] created a friendly alarm clock with a touchscreen LCD. Much like the Chumby, this clock packs a WiFi module.

In this case though, the WiFi module is an ESP8266, whose on-board Xtensa microcontroller runs the whole show. [Spiros] programmed his Sparkfun ESP8266 Thing in C++. To keep costs down, [Spiros] left out anything unnecessary – like a real-time clock module. The Chumby-lite uses NTP to stay regular. The reductions paid off – this clock can be built for around $13.00, not including the very nice 3D printed case.

1983[Wanderingmetalhead] takes us all way back to 1983 with his 7 Day Alarm Clock. 32 years ago, this was [wanderingmetalhead’s] first embedded system project. As the name implies, this clock stores a different wake time for each day of the week. Actual numeric entry sure beats the old “hold two buttons and watch the numbers spin” system.

This is an oldie. The system is based upon a Motorola (which became Freescale, and is now NXP) 6802 micro. The code was written in assembly and cross-assembled on an Apple II. A 3.58MHz colorburst crystal divided down to 60 Hz provides the time base. This setup wasn’t perfect, but good down to a about a minute a month. The whole project lived and worked in an old amplifier case, where it dutifully woke [wanderingmetalhead] each day for 17 years.

If you want to see more alarm clock projects, check out our new alarm clocks list! If I didn’t wake up early enough to catch your project, don’t be shy, just drop me a message on That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of!

Why Starting a Kickstarter Could Kick Your Butt

So you’ve come up with a great idea and now you’re thinking about starting a crowdfunding campaign – and why not, all the cool kids are doing it. Now, let’s say you already have a working prototype, or maybe you even built a small run for friends online. You’ve made 10 here, or 20 there. Sure it took some time, but making 1000, or 10,000 would be so much easier once you get all the orders in, right? Wrong.

Before you even think of setting up something like a Kickstarter, we would like to invite you to have a seat and watch this series of videos covering the things many people don’t know about manufacturing. It’s going to cost you 7 hours of sofa time, but if you’re serious about getting something to production these seven hours will pay in spades. Dragon Innovation has had many notable clients over the years – Pebble, Sphero, Makerbot, to name a few. They help startups find their way through the manufacturing mine-feild, for a fee of course. The founders are former iRobot employees, and have quite a bit of hard fought, yet free knowledge to share.

You’ll learn about how important decisions early on can make huge impacts on the success or failure of a product. There’s quite a bit of raw technical info on injection molding, design for manufacture, testing, pricing and everything under the sun. So do yourself (and everyone else) a favor, and before you click submit on that Kickstarter campaign, sit back and enjoy this free seminar.

We’re really enjoying the manufacturing oriented videos which have been popping up. Just a couple of weeks ago we came across a pair of hardware talks from [Bunnie Huang] that were a pleasure to watch. At 20 minutes this might be a good primer before you take the plunge with the playlist below.

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Sex and Blinky LEDs At Burning Man

[Bunnie] was at Burning Man this year, and to illuminate his camp members in the dark and dusty nights of the playa, he created a blinky badge. This isn’t just any badge stuffed with RGB LEDs; each of the badges were unique by the end of Burning Man. These badges were made unique not by twiddling dials or pressing buttons; all the color patterns were bred with badge sex.

This social experiment to replicate nature’s most popular means of creating more nature is built around a peer to peer radio. Each badge is equipped with a radio, a circle of RGB LEDs, and a bit of code that expresses the pattern of lights on the badge as a sequence of genes. When one badge gives consent to another badge, they ‘breed’, creating a new pattern of lights. If you’re wondering about the specifics of the act, each badge is a hermaphrodite, and each badge transmits a ‘sperm’ to fertilize the other plant’s ‘egg’. There’s even a rare trait included in the genome of the badge; each badge has a 3% chance of having a white pixel that moves around the circle of LEDs. [Bunnie] found this trait was more common after a few days, suggesting that people were selectively breeding their badges.

Of course, finding potential mates is a paramount concern for any sexual organism, and the sex badge has this covered, too. The 900MHz radio listens for other badges in close proximity, and when any are found their owners are displayed on an OLED display. This came in handy for [Bunnie] more than a few times – there’s no phones out there, and simply knowing your friends are within a hundred meters or so is a big help.

The entire badge platform is documented online, along with the code and spec for badge genes. Badges with some sort of wireless communication have been around for a while, but this is the first time that communication has been used for something more than sharing contact information or implementing a chat room. It’s a great idea, and something we hope to see more of in future con badges.