The Devil Is In The Details

July 3, 2021 by Elliot Williams 28 Comments

If you’ve taken a physics class, you’ve doubtless heard tales of mythical beasts like the massless string, the frictionless bearing, and the perfect sphere. And if you’re designing something new, it’s not always wrong to start by thinking in terms of these abstractions, just to get the basic framework laid and a first-order handle on the way things go. But once you start building, you’d better be ready to shed your illusions that a 6 mm peg will fit into a 6 mm hole.

Theory and practice are the same thing, in theory. But as soon as you step into practice, your “weekend build” can easily turn into a 500-hour project, full of hurdles, discoveries, experimentation, and eventual success. I’m not going to rehash [Scott Rumschlag]’s project here — you should really watch his detailed video — but suffice it to say that when building a sub-millimeter precision 3D measuring device, bearings do have friction and string does have non-zero mass, and it all matters.

When you start working on a project that “looked good on paper” or for whatever reason just doesn’t turn out as precisely as you’d wished, you could do worse than to follow [Scott’s] example: start off by quantifying your goals, and then identify where every error along the way accumulates to keep you from reaching them. Doing precise work isn’t easy, but it’s not impossible either if you know where all the errors are coming from. You at least have a chain of improvements that you can consider, and if you’ve set realistic goals, you also know when to stop, which is almost as important.

And if anyone out there has an infinite sheet of perfectly conductive material, I’m in the market.

How Did I Live Without A Microscope?

June 26, 2021 by Elliot Williams 48 Comments

Get yourself a decent stereo inspection microscope, preferably optical. Something that can magnify from maybe 4x to 40x is fine, anything outside this range is icing on the cake. Some people claim they’re fine with a minimum of 10x, but if you go there, you’re going to need a reducing lens eventually. Either way, get one, and you’ll thank me.

How do I know this? I finally caved in and bought one about two years ago now, and while it’s not something I use daily, it’s something that I use at least once a month and for which there is simply no substitute.

This is Hackaday, so a lot of you will be thinking “inspection scope = fine-pitch soldering” and you’re not wrong. With clearance of 10 cm or more, and a slab of sacrificial optical glass (“neutral density filter”) to protect the optics from tarry flux fumes, a stereo scope at 4x makes even the fiddliest solder joints possible. Good lighting, and sharp tweezers are also a must, of course. That’s what got me in the door.

But that’s the half of it, or less. When my scope was new to me — it hasn’t been “new” since the late 1980s — we spent a whole rainy Sunday afternoon microscoping whatever would fit under the lens. Grains of salt, blades of grass, all manner of bugs living and otherwise, shells, skin, textiles. Everything is cooler under the microscope.

The event that triggered this article wasn’t my son’s school project this week to photograph dandelion seeds. Nope, today my wife found a bug in the basement; to the microscope! And with a very quick and unfortunately very positive identification, we now know that we have to strain all of our flour for bread beetles and pitch whichever bags they came in with. Hooray!

The inspection scope was intended for the soldering bench, but has found general use as an irreplaceable household tool. While I admittedly also intended to use it to lure my son into science, the real fight over scope time has been with my wife. And that’s why you want an optical scope instead of one that’s tethered to a monitor — as a general-purpose tool, portability is paramount. No menu diving, no power source, and anyone can just grab it and go.

Convinced? Ready to pull out your wallet? Microscopes are like cars. You can spend as much as you’d like on one, the cheapest will cause you nothing but pain and suffering, and the difference between the mid-range and high-end is full of diminishing returns. Buying used, especially if you can kick the metaphorical tires, can be a great bargain, and a high-end used scope will hold its value a lot better than a new budget model. Just around $200 is a sweet spot new and $300-$400 will get you the top of the line from yesteryear if you shop around. That’s not cheap, but if you’re the microscope type, it’s easily worth it. Trust me.

Growing Up With Computers

June 19, 2021 by Elliot Williams 78 Comments

My son is growing up with computers. He’s in first grade, and had to list all of the things that he knows how to do with them. The list included things like mousing around, drawing ghosts with the paint program, and — sign of the times — muting and unmuting the microphone when he’s in teleconferences. Oh yeah, and typing emojis. He loves emojis.

When I was just about his age, I was also getting into computers. But home computers back then were in their early years as well. And if I look back, I’ve been getting more sophisticated about computers at just about the same pace that they’ve been getting more sophisticated themselves. I was grade school during the prime of the BASIC computers — the age of the Apple II and the C64. I was in high school for the dawn of the first Macs and the Amiga. By college, the Pentiums’ insane computational abilities just started to match my needs for them to solve numerical differential equations. And in grad school, the rise of the overclockable multi-cores and GPUs powered me right on through a simulation-heavy dissertation.

When I was a kid, they were playthings, and as a grownup, they’re powerful tools. Because of this, computers have never been intimidating. I grew up with computers.

But back to my son. I don’t know if it’s desirable, or even possible, to pretend that computers aren’t immensely complex for the sake of a first grader — he’d see right through the lie anyway. But when is the right age to teach kids about voice recognition and artificial neural networks? It’s a given that we’ll have to teach him some kind of “social media competence” but that’s not really about computers any more than learning how to use Word was about computers back in my day. Consuming versus creating, tweeting versus hacking. Y’know?

Of course every generation has its own path. Hackers older than me were already in high-school or college when it became possible to build your own computer, and they did. Younger hackers grew up with the Internet, which obviously has its advantages. Those older than me made the computers, and those younger have always lived in a world where the computer is mature and taken for granted. But folks about my age, we grew up with computers.

What Every Geek Must Know

June 12, 2021 by Elliot Williams 176 Comments

How is it possible that there’s a geek culture? I mean, it’s one thing to assume that all folks of a nerdy enough bent will know a little Ohm’s law, can fake their way through enough quantum mechanics to at least be interesting at a cocktail party, and might even have a favorite mnemonic for the resistor colors or the angles involved in sine, cosine, and tangents. But how is it that we all know the answer to life, the universe, and everything?

Mike and I were podcasting a couple of weeks back, and it came out that he’d never played Starcraft. I was aghast! Especially since he’s into video games in general, to have not played the seminal 3-way-without-being-rock-scissors-paper game! My mind boggled. But then again, there was a time in my life when I hadn’t actually read all of Dune or Cryptonomicon, which would have left Mike’s jaw on the floor.

Whether you prefer Star Trek or Star Wars, the Matrix or the Hobbit, it’s even more surprising that we have so much in common! And thinking about it, I’m pretty sure that exactly our interchange is the reason — it’s a word of mouth culture thing. Some folks at the hackerspace are talking about Cthulu, and chances are you’re going to be reading some Lovecraft. An argument about the plausibility of the hacks in The Martian has sent at least a couple of geeks to the cinema or the library. And so it goes.

So do your part! Share your geek-culture recommendations with us all in the comments. If you were stranded on a desert island, with a decent bookshelf and maybe even a streaming video service, what’s on your top-10 list? What do you still need to see, read, or hear?

Living Robots: Revisiting BEAM

May 29, 2021 by Elliot Williams 40 Comments

You’re hit by the global IC shortage, reduced to using stone knives and bearskins, but you still want to make something neat? It’s time to revisit BEAM robots.

Biology, electronics, aesthetics, and mechanics — Mark Tilden came up with the idea of minimalist electronic creatures that, through inter-coupled weak control systems and clever mechanical setups, could mimic living bugs. And that’s not so crazy if you think about how many nerves something like a cockroach or an earthworm have. Yet their collection of sensors, motors, and skeletons makes for some pretty interesting behavior.

My favorite BEAM bots have always been the solar-powered ones. They move slowly or infrequently, but also inexorably, under solar power. In that way, they’re the most “alive”. Part of the design trick is to make sure they stay near their food (the sun) and don’t get stuck. One of my favorite styles is the “photovore” or “photopopper”, because they provide amazing bang for the buck.

Back in the heyday of BEAM, maybe 15 years ago, solar cells were inefficient and expensive, circuits for using their small current were leaky, and small motors were tricky to come by. Nowadays, that’s all changed. Power harvesting circuits leak only nano-amps, and low-voltage MOSFETs can switch almost losslessly. Is it time to revisit the BEAM principles? I’d wager you’d put the old guard to shame, and you won’t even need any of those newfangled microcontroller thingies, which are out of stock anyway.

If you make something, show us!

IRC Will Never Die

May 22, 2021 by Elliot Williams 51 Comments

The big kerfuffle in the open source world this week surrounds the biggest IRC server operator, Freenode. Wherever the dust settles, myriad important open source projects use Freenode’s IRC servers for their main channel of user feedback, and a number of vibrant communities call or called Freenode home. What you would call a 3D printer, and most of the software that drives it, for instance, was brainstormed up in Freenode’s #reprap. If you want help with a Linux distribution, you’ll be set straight within a few minutes in the relevant channel, because the people who wrote, packaged, or maintain it are probably on Freenode waiting to chat.

But suppose Freenode burns to the ground tomorrow, as some are suggesting. So what? My take is that is doesn’t matter. Freenode doesn’t own IRC, setting up an IRC server is essentially trivial, and what’s really important is the online community — they can just pick up and move somewhere else with very little hassle.

This is not to say that we don’t all benefit from the diligence that Freenode’s volunteer administrators and operators have donated to the cause over the years. IRC servers don’t run themselves, and Freenode’s admins fought and won an epic battle with spammers a couple years back. Keeping IRC running at scale is a different thing than setting up something for your friends, and so the Freenode folks definitely deserve our thanks.

But look, IRC is an old protocol and it’s a simple protocol. It’s so simple, in fact, that writing an IRC bot is just a few dozen lines in Python, using no external libraries. All you need to do is send plain text over a socket. You can do this — it makes a great networking hello world.

IRC is fun for hackers, but if you want a user-friendly GUI client, you ridiculously many to choose from. There are even no-install web clients if you just want to dip your toes in. Heck, you could install your own server in an hour or so.

So saying that the demise of Freenode is the end of IRC is a lot like saying that the end of Hotmail was the end of e-mail. In the grand scheme of things, almost nobody actually uses IRC — Freenode has 78,000 users while Slack has 10 million — and IRC users are very savvy, if not full-on geeky. These are the sort of people who can probably find the server field in a menu and change it from irc.freenode.net to irc.whatever.org.

In addition to our traditional #hackaday channel on irc.freenode.net, there’s also a channel set up on irc.libera.chat as well. There isn’t much action in either — IRC tends to be a slow conversation, so don’t freak out if someone responds to you an hour later — but if you want to swing by, we’re there. IRC will never die!

2021 Hackaday Prize Begins!

If you missed our announcement, this year’s Hackaday Prize is on! We’ve all had a rough year and a half, and it’s lead a lot of us to think seriously about our world. How would you want to change it going forward? Fifty entrants will rethink, refresh, and rebuild their way into $500, and the Grand Prize is $25,000. Get hacking!