Fifty Shades of Gray Code

Some years back, a museum asked me to help them with an exhibit a contractor had built for them. It was a wheel like the one on Wheel of Fortune, but smaller and mounted on the wall instead of the floor. You would spin the wheel, it would stop on some item, and a computer would play a short video about the item. Physically and mechanically, it was a beautifully built exhibit. The electronics, though, left something to be desired.

In principle, this is pretty simple computer task. Measure the position of the wheel, and when it stops moving, play a video based on the position. The problem was the folks who created the artistic mechanics didn’t think hard about the electronics behind it. Sometimes–but not often–the wheel would play the wrong video. Sometimes it wouldn’t play at all.

The Prime Suspect

My immediate suspicion turned out to be correct. I took the wheel off its mount to discover copper foil tape on the back of it. Each pie wedge had foil in different areas and there were two brushes in each area. When the wheel stopped, two of the brushes would be shorted together and the rest were open. The way they detected that was bizarre, but that wasn’t the problem. (It involved a cannibalized PS/2 keyboard.)
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Noise Cancelling Speech Recogntion

If you are like us, you’ll read a bit more and smack your forehead. Amazon recently filed a patent. That isn’t really news, per se–they file lots of patents, including ones that cover clicking on a button to order something and taking pictures against white backgrounds (in a very specific way). However, this patent is not only a good idea, but one we were surprised didn’t arise out of the hacker community.

There can’t be an invention without a problem and the problem this one solves is a common one: While wearing noise cancelling headphones, you can’t hear things that you want to hear (like someone coming up behind you). The Amazon solution? Let the headphones monitor for programmable keywords and turn off noise cancellation in response to those words. We wonder if you could have a more sophisticated digital signal processor look for other cues like a car horn, a siren, or a scream.

We’ve talked about fixing commercial noise cancelling headphones before. If you don’t mind going low-tech, there’s always the easy way out, but those aren’t likely to accommodate speech recognition.

The Politest Patent Discussion, OSHW v. Patents

We’ve covered [Vijay] refreshable braille display before. Reader, [zakqwy] pointed us to an interesting event that occured in the discussion of its project page.

[Vijay] was inspired by the work of [Paul D’souza], who he met at Makerfaire Bangalore. [Paul] came up with a way to make a refreshable braille display using small pager motors. [Vijay] saw the light, and also felt that he could make the vibrating motor display in such a way that anyone could make it for themselves at a low cost.

Of course, [Paul], had patented his work, and in this case rightly so. As jaded as we have become with insane patent trolls, our expectation on receiving the tip was that [Paul] had sued [Vijay] out of house and home and kicked his dog while he was at it. A short google search shows that [Paul] is no patent troll, and is a leader in his field. He has done a lot to help the visually impaired with his research and inventions.

Instead we were greeted by a completely different conversation. [Paul] politely mentioned that his lawyer informed him that in order to protect his IP he needed to let [Vijay] know exactly how the information could be used. No cease and desist, in fact he encouraged [Vijay] to continue his open research as long as he made it clear that the methods described could not be used to make a marketable product without infringing on [Paul]’s patents. They’d need to get in touch with [Paul] and work something out before doing such.

[Vijay] responded very well to this information. His original goal was to produce a cheap braille display that could be made and sold by anyone. However, he did use [Paul]’s work as a basis for his variation. Since [Paul]’s commercial interests relied on his patent, there was a clear conflict, and it became obvious to [Vijay] that if he wanted to meet his goal he’d have to pick a new direction. So, he released his old designs as Creative Commons, since the CERN license he was using was invalidated by [Paul]’s patent. He made it very clear that anyone basing their work off those designs would have to get in touch with [Paul]. Undaunted by this, and still passionate about the project, [Vijay] has decided to start from scratch and see if he can invent an entirely new, unprotected mechanism.

Yes, the patent system is actually encouraging innovation by documenting prior work while protecting commercial and time investments of beneficial inventors. Well. That’s unexpected.

Kudos to [Paul] for encouraging the exploration of home hackers rather than playing the part of the evil patent owner we’ve all come to expect from these stories. Also [Vijay], for acting maturely to [Paul]’s polite request and not ceasing his work.

The Sincerest Form of Flattery: Cloning Open-Source Hardware

We’re great proponents (and beneficiaries) of open-source hardware here at Hackaday. It’s impossible to overstate the impact that the free sharing of ideas has had on the hacker hardware scene. Plus, if you folks didn’t write up the cool projects that you’re making, we wouldn’t have nearly as much to write about.

We also love doing it ourselves. Whether this means actually etching the PCB or just designing it ourselves and sending it off to the fab, we’re not the types to pick up our electronics at the Buy More (except when we’re planning to tear them apart). And when we don’t DIY, we like our electrons artisanal because we like to support the little guy or girl out there doing cool design work.

So it’s with a moderately heavy heart that we’ll admit that when it comes to pre-built microcontroller and sensor boards, I buy a lot of cheap clones. Some of this is price sensitivity, to be sure. If I’m making many different one-off goofy projects, it just doesn’t make sense to pay the original-manufacturer premium over and over again for each one. A $2 microcontroller board just begs to be permanently incorporated into give-away projects in a way that a $20 board doesn’t. But I’m also positively impressed by some of the innovation coming out of some of the clone firms, to the point that I’m not sure that the “clone” moniker is fair any more.

This article is an attempt to come to grips with innovation, open source hardware, and the clones. I’m going to look at these issues from three different perspectives: the firm producing the hardware, the hacker hobbyist purchasing the hardware, and the innovative hobbyist who just wants to get a cool project out to as many people as possible. They say that imitation is the sincerest form of flattery, but can cloning go too far? To some extent, it depends on where you’re sitting.

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Smarter-than-wood Saw Blade Makes Perfect Foldable Joints

[Andrew Klein] knows the pain of building drawers from plywood. It can be a pain to get all of the pieces measured and cut just right. Then you have to line them up, glue them together, and clamp them perfectly. It’s time-consuming and frustrating. Then one day it hit him that he might be able to make the whole process much easier using a custom saw blade.

The the video below, [Andrew] does a great job explaining how the concept works using a piece of paper. The trick is that the plywood must be cut in a very specific shape. This shape results in the plywood just barely being held together, almost as if it’s hinged. The resulting groove can then be filled with wood glue, and the plywood is folded over on itself. This folding process leaves no gaps in the wood and results in a strong joint. Luckily this special shape can be cut with a specialized saw blade.

This new process removes the requirement of having five separate pieces for a drawer. Instead, only four cuts are needed on a single piece of square plywood. The corners are then removed with a razor blade and all four sides are folded up and into place. [Andrew] shows that his prototype blade needs a little bit of work, but he’s so hopeful that this new invention will be useful to others. Continue reading “Smarter-than-wood Saw Blade Makes Perfect Foldable Joints”

The Original Seven (Eight?) Segment Display

The seven-segment LED display is ubiquitous. But how old do you think the fundamental idea behind it is? You nixie tube fans will be thinking of the vacuum-tube era, but a reader sent us this patent filed in 1908 where [Frank W. Wood] builds a numeric display with plain-vanilla light bulbs, slots cut in wood, and lots of wires.

The OCR on the patent is poorly done — you’re going to want to download the PDF and read it locally. But as it states in the patent, “Referring again to Fig. 1, the novel arrangement of the lamp compartments will be readily understood.”

Technically it’s not a seven-segment display at all. [F.W. Wood] designed these really nice-looking “4”s with the diagonal heads, and so he needed eight segments per digit. But the basic idea shines through, if you pardon the pun.

The other figures demonstrate the machine that’s used to send the signals to light up the lights. It’s a rotating drum with the right contacts on the bottom side to make connections and turn on the right lights at the other end. Low tech, but it’s what was available at the time.

We’re stoked that we’re not responsible for wiring this thing up, and we’re a bit awed by how old the spirit behind one of our most ubiquitous technologies is.

Thanks to [mario59] for the nostalgic tip!

3D Printering: A Call for an Open Source Automated Build Platform

I’ve said this before, and I’ll say it again: if you’re using a 3D printer to make a few hundred identical plastic parts, you’re doing it wrong. That’s the place for traditional manufacturing methods such as injection molding or resin casting. If, however, you’re looking at printing a few dozen identical plastic parts, or even running a script to optimize your machine time, the current open source 3D printer world leaves one thing to be desired.

An Automated Build Platform

An Automated Build Platform is a fairly simple idea: put a conveyor belt on your heated bed, and when the print is done, send a command to drive a motor, dumping the newly printed part into a bin, The printer then begins the next part with a clean bed, and the days of doting over a 3D printer soon fade into the past.

For such a simple and useful idea, it’s surprising there hasn’t been much done with this idea in open source circles. There are, of course, problems both technical and legal, but hopefully nothing that should indefinitely derail anyone who would want to create the first open source automated build platform.

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