Ask Hackaday: How Should Hackers Handle IP Agreements?

My buddy Harold recently landed a new job at a great technology company. It came at a perfect time for him, having just been laid off from the corporate behemoth where he’d toiled away as an anonymous cog for 19 years. But the day before he was to start, the new company’s HR folks sent him some last-minute documents to sign. One was a broad and vaguely worded non-compete agreement which essentially said he was barred from working in any related industry for a year after leaving the company.

Harold was tempted not to sign, but eventually relented because one needs to put food on the table. Thankfully he’s now thriving at the new company, but his experience got me thinking about all the complications hackers face with the day jobs that so many of us need to maintain. Non-competes and non-disclosures are bad enough, but there’s one agreement that can really foul things up for a hacker: the Intellectual Property Agreement.

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Ask Hackaday: Bitten by the Crocodile Clip

I have a love/hate relationship with the crocodile clip. Nothing is so quick to lash together a few half-baked prototype boards on your desk, but nothing ends up in such a tangle so quickly, either. I love the range of pretty colors that crocodiles come in, as well as the easy ability to just clip on to the side of a PCB, or any old loose wire. But they come loose, they can have intermittent contacts, and we’re not even sure if there is such a thing as a current rating for them.

When [WarriorRocker] wrote in asking what we use instead of crocodile clips, he included a photo that sent a chill down my spine, from a review of some clips on Amazon. I’ve seen this one in real life. And what’s worse is the one with the loose wires that sometimes make contact with the spring-clip body and sometimes not.

After an hour-long debugging session about twelve years ago now, such an intermittent croc caused us to make a lifelong vow. All of our croco-clips have been disassembled, manually inspected, and many of them soldered together. When I buy new ones, I check them all before mixing them in with the known-goods. Even thinking about this now makes me want to pull back their little rubber booties just to make sure. Continue reading “Ask Hackaday: Bitten by the Crocodile Clip”

Ask Hackaday: Is Owning A 3D Printer Worth It?

3D printers are the single best example of what Open Hardware can be. They’re useful for prototyping, building jigs for other tools, and Lulzbot has proven desktop 3D printers can be used in industrial production. We endorse 3D printing as a viable tool as a matter of course around here, but that doesn’t mean we think every house should have a 3D printer.

Back when Bre was on Colbert and manufacturing was the next thing to be ‘disrupted’, the value proposition of 3D printing was this: everyone would want a 3D printer at home because you could print plastic trinkets. Look, a low-poly Bulbasaur. I made a T-rex skull. The front page of /r/3Dprinting. Needless to say, the average consumer doesn’t need to spend hundreds of dollars to make their own plastic baubles when WalMart and Target exist.

The value proposition of a 3D printer is an open question, but now there is some evidence a 3D printer provides a return on its investment. In a paper published this week, [Joshua Pearce] and an undergraduate at Michigan Tech found a 3D printer pays for itself within six months and can see an almost 1,000% return on investment within five years. Read on as I investigate this dubious claim.

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Ask Hackaday: Are Unlockable Features Good for the User?

There are numerous examples of hardware which has latent features waiting to be unlocked by software. Most recently, we saw a Casio calculator which has the same features as its bigger sibling hidden within the firmware, only to be exposed by a buffer overflow bug (or the lead from a pencil if you prefer a hardware hack).

More famously, oscilloscopes have been notorious for having crippled features. The Rigol DS1052E was hugely popular on hacker benches because of it’s very approachable price tag. The model shipped with 50 MHz bandwidth but it was discovered that a simple hack turned it into the DS1102E 100 MHz scope. Tektronix has gotten in on this action as well, shipping modules like I2C, CAN, and LIN analyzation on the scope but requiring a hardware key to unlock (these were discovered to have a horribly insecure unlock method). Similar feature barriers are found on Rigol’s new reigning entry-level scope, the DS1054Z, which ships with protocol analyzation modules (among others) that are enabled only for the first 70 hours of scope operation, requiring an additional payment to unlock them. Most scope manufacturers are in on the game, and of course this is not limited to our tools. WiFi routers are another great example of hardware hosting firmware-unlockable features.

So, the question on my mind which I’d like to ask all of the Hackaday community is this: are unlockable features good for us, the people who use these tools? Let’s take a look at some of the background of these practices and then jump into a discussion in the comments.

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Ask Hackaday: Computing Square Roots on FPGA?

Hackaday reader [] wrote in with some code from a project that resizes a video stream on the fly using an FPGA. Doing this right means undoing whatever gamma correction has been applied to the original stream, resizing, and then re-applying the gamma. Making life simpler, [] settled on a gamma of two, which means taking a bunch of square roots, which isn’t fast on an FPGA.

[nats]’s algorithm is pretty neat: it uses a first-stage lookup to figure out in which broad range the value lies, and then one step of Hero’s algorithm to refine from there. (We think this is equivalent to saying he does a piecewise linear interpolation, but we’re not 100% sure.) Anyway, it works decently.

Of course, when you start looking into the abyss that is special function calculation, you risk falling in. Wikipedia lists more methods of calculating square roots than we have fingers. One of them, CORDIC, avoids even using multiplication by resorting to clever bitshifts and a lookup table. Our go-to in these type of situations, Chebyshev polynomial approximation, didn’t even make the cut. (Although we suspect it would be a contender in the gamma=1.8 or gamma=2.2 cases, especially if combined with range-reduction in a first stage like [] does.)

So what’s the best/fastest approximation for sqrt(x) for 16-bit integers on an FPGA? [] is using a Spartan 6, so you can use a multiplier, but division is probably best avoided. What about arbitrary, possibly fractional, roots?

Ask Hackaday: Dude, Where’s My MOSFET?

(Bipolar Junction) Transistors versus MOSFETs: both have their obvious niches. FETs are great for relatively high power applications because they have such a low on-resistance, but transistors are often easier to drive from low voltage microcontrollers because all they require is a current. It’s uncanny, though, how often we find ourselves in the middle between these extremes. What we’d really love is a part that has the virtues of both.

The ask in today’s Ask Hackaday is for your favorite part that fills a particular gap: a MOSFET device that’s able to move a handful of amps of low-voltage current without losing too much to heat, that is still drivable from a 3.3 V microcontroller, with bonus points for PWM ability at a frequency above human hearing. Imagine driving a moderately robust small DC robot motor forwards with a microcontroller, all running on a LiPo — a simple application that doesn’t need a full motor driver IC, but requires a high-efficiency, moderate current, and low-voltage-logic compatible transistor. If you’ve been here and done that, what did you use?

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Ask Hackaday: What’s Your Favorite Internet Relic?

[Sadiq Mohamed] posted this great list of light bulb jokes in our post about drones changing light bulbs. This favored relic used to exist on a Compuserve SIG, but fortunately a dedicated user had saved the list.

There have been virtual worlds long before our computers could render anything but potatoes with anime faces. Bulletin boards, mailing lists, and forums dominated and then fell, for the most part, to social media. In a way even the personal home page has gone to the wayside. (remember geocities?)

The internet has gone through many phases of development. We’ve experimented with lots of concepts and when they fail or go out of style, there are ghost towns of information left untouched.

However, we remember. I still think fondly of my old shell server. Some of it is even history worthy enough to be in the books. What’s your favorite piece of internet gone by or just plain internet obscura? An old joke? A book five layers deep in a file structure somewhere. Or maybe just the 1959 definition of the word, “hack,” in the Tech Model Railroad Club’s first edition dictionary.