Ask Hackaday: What Was Your First Electronics Win?

August 1, 2022 by Dan Maloney 74 Comments

Back in high school, I joined the stage crew — because of course I did. As student theater groups go, it was pretty active, and with two shows to produce each year, there was always a lot of work to do. I gravitated to the lighting crew, which was a natural fit for me. Besides the electrical part of the job, there was also a lot of monkeying around on scaffolding and rickety ladders to hang the lights, which was great fun for the young and immortal. Plus there was the lighting console to run during performances, a job I eventually took over for my last two years.

Unfortunately, the lighting system was a bit pathetic. The console was mounted in the stage right wings, rather than out in the front of the house where a sensible person would put it. And despite being only about ten years old, the dimmers were already starting to fail. The board had about 20 channels, but you could always count on one of the channels failing, sometimes during a show, requiring some heroics to repatch the lights into one of the dimmers we always left as a spare, just for the purpose.

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Hackaday Links: July 31, 2022

July 31, 2022 by Dan Maloney 12 Comments

Don’t look up! As of the time of this writing, there’s a decent chance that a Chinese Long March 5B booster has already completed its uncontrolled return to Earth, hopefully safely. The reentry prediction was continually tweaked over the last week or so, until the consensus closed in on 30 Jul 2022 at 17:08 UTC, give or take an hour either way. That two-hour window makes for a LOT of uncertainty about where the 25-ton piece of space debris will end up. Given the last prediction by The Aerospace Corporation, the likely surface paths cover a lot of open ocean, with only parts of Mexico and South America potentially in the crosshairs, along with parts of Indonesia. It’s expected that most of the material in the massive booster will burn up in the atmosphere, but with the size of the thing, even 20% making it to the ground could be catastrophic, as it nearly was in 2020.

[Update: US Space Command confirms that the booster splashed down in the Indian Ocean region at 16:45 UTC. No word yet on how much debris survived, or if any populated areas were impacted.]

Good news, everyone — thanks to 3D printing, we now know the maximum height of a dive into water that the average human can perform without injury. And it’s surprisingly small — 8 meters for head first, 12 meters if you break the water with your hands first, and 15 meters feet first. Bear in mind this is for the average person; the record for surviving a foot-first dive is almost 60 meters, but that was by a trained diver. Researchers from Cornell came up with these numbers by printing models of human divers in various poses, fitting them with accelerometers, and comparing the readings they got with known figures for deceleration injuries. There was no mention of the maximum survivable belly flop, but based on first-hand anecdotal experience, we’d say it’s not much more than a meter.

Humans have done a lot of spacefaring in the last sixty years or so, but almost all of it has been either in low Earth orbit or as flybys of our neighbors in the Sol system. Sure we’ve landed plenty of probes, but mostly on the Moon, Mars, and a few lucky asteroids. And Venus, which is sometimes easy to forget. We were reminded of that fact by this cool video of the 1982 Soviet landing of Venera 14, one of only a few attempts to land on our so-called sister planet. The video shows the few photographs Venera 14 managed to take before being destroyed by the heat and pressure on Venus, but the real treat is the sound recording the probe managed to make. Venera 14 captured the sounds of its own operations on the Venusian surface, including what sounds like a pneumatic drill being used to sample the regolith. It also captured, as the narrator put it, “the gentle blow of the Venusian wind” — as gentle as ultra-dense carbon dioxide hot enough to melt lead can be, anyway.

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Hackaday Podcast 179: Danger Chess, Corona Motors, An Omni-Walker, And A Fast Talking Telescope

July 29, 2022 by Dan Maloney 3 Comments

Join Hackaday Editor-in-Chief Elliot Williams and Staff Writer Dan Maloney for their take on the hottest hacks in a hot, hot week. We found a bunch of unusual mechanisms this week, like an omnidirectional robot that’s not quite wheeled but not quite a walker either. Or, if you’d rather fly, there’s a UAV that’s basically a flying propeller. There’s danger afoot too, with news of a chess-playing robot with a nasty streak, a laser engraver that’ll probably blind you, and a high-voltage corona motor that actually does useful work. We’ll use our X-ray vision to take a deep dive into a 60-GHz phased array antenna, let a baby teach a machine what it means to be hungry, and build a couple of toy cameras just for funsies. Balloons as a UI? Maybe someday, thanks to ultrasonic levitation. And we’ll wrap things up by snooping in on the Webb telescope’s communications, as we find out how many people it takes to make wire harnesses. Spoiler alert: it’s a lot.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download here!

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PERSEUS-9, The Dual-6502 Portable Machine That Should Have Been

July 29, 2022 by Dan Maloney 53 Comments

A question: does anyone who was around in the early days of the 8-bit computer revolution remember a dual-CPU 6502 portable machine like this one? Or just a dual-CPU machine? Or even just a reasonably portable computer? We don’t, but that begs a further question: if [Mitsuru Yamada] can build such a machine today with parts that were available in the era, why weren’t these a thing back then?

We’re not sure we have an answer to that question, but it just may be that nobody thought of it. Or, if they did, the idea of putting two expensive CPUs into a single machine was perhaps too exorbitant to take seriously. Regardless, the homemade mobile is another in a growing line of beautifully crafted machines in the PERSEUS line, all of which have a wonderfully similar look and feel.

For the PERSEUS-9, [Yamada-san] chose a weatherproof aluminum enclosure with just the right form-factor for a mobile computer, as well as a sturdy industrial look. Under the hood, there are two gorgeous wire-wrap boards, one of which is home to the 48-key keyboard and the 40×7 alphanumeric LED matrix display, while the other is a densely packed work of art holding the two 6502s and a host of other DIPs.

The machine is a combination of his PERSEUS-8 computer, his 6802 serial terminal, and the CI-2 floating point interpreter he built for the PERSEUS-8. A brief video of the assembly of this delightful machine is below. One of the many things about these builds that impress us is the precision with which the case is machined, apparently all by hand. How he managed to drill out all those holes for the keyboard without having one even slightly out of alignment without the aid of CNC is beyond us.

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The Surprisingly Manual Process Of Building Automotive Wire Harnesses

July 27, 2022 by Dan Maloney 117 Comments

Even from the very earliest days of the automobile age, cars and trucks have been hybrids of mechanical and electrical design. For every piston sliding up and down in a cylinder, there’s a spark plug that needs to be fired at just the right time to make the engine work, and stepping on the brake pedal had better cause the brake lights to come on at the same time hydraulic pressure pinches the wheel rotors between the brake pads.

Without electrical connections, a useful motor vehicle is a practical impossibility. Even long before electricity started becoming the fuel of choice for vehicles, the wires that connect the computers, sensors, actuators, and indicators needed to run a vehicle’s systems were getting more and more complicated by the year. After the engine and the frame, a car’s wiring and electronics are its third most expensive component, and it’s estimated that by 2030, fully half of the average vehicle’s cost will be locked in its electrical system, up from 30% in 2010.

Making sure all those signals get where they’re going, and doing so in a safe and reliable way is the job of a vehicle’s wire harnesses, the bundles of wires that seemingly occupy every possible area of a modern car. The design and manufacturing of wire harnesses is a complex process that relies on specialized software, a degree of automation, and a surprising amount of people-power.

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A Tiny Forest Of Resistors Makes For Quick And Dirty Adaptive Optics

July 25, 2022 by Dan Maloney 16 Comments

The term “adaptive optics” sounds like something that should be really complicated and really expensive. And in general, the ability to control the properties of optical elements is sufficiently difficult enough that it’s reserved for big-science stuff like billion-dollar space telescopes.

But that doesn’t mean there aren’t quick and dirty adaptive optics that are suitable for the budget-minded experimenter, like this thermally deformable mirror. As [Zachary Tong] explains, this project, which started quite some time ago, is dead simple — a 4 by 4 array of through-hole resistors stand on end, and these are attached to a glass coverslip that has been aluminized on one side. An Arduino and a couple of shift registers make it possible to individually address each of the 16 resistors in the array. Passing a current through a resistor heats it up a bit, leading to thermal expansion and a slight deflection of the mirror sitting on top of the array. Controlling which resistors heat up and by how much should lead to deformation of the mirror surface in a predictable way.

The video below shows some of [Zach]’s experiments with the setup. Unfortunately, he wasn’t able to fully demonstrate its potential — the low-quality mirror didn’t cooperate with his homebrew interferometer. He was, however, able to use a dial indicator to show deflection of the mirror in the 2- to 3-micron range by heating the array. That alone is pretty cool, especially given the dirt cheap nature of the build.

As for practical uses, don’t get too excited. As [Zach] points out, thermal systems like this will probably never be as fast as MEMS or piezoelectric actuators, and many use cases for adaptive optics really don’t react well to added heat. But changing the shape of a mirror with air pressure is another thing.

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Hackaday Links: July 24, 2022

July 24, 2022 by Dan Maloney 6 Comments

OK, maybe that won’t buff right out. NASA has released a more detailed analysis of the damage suffered by the James Webb Space Telescope in a run-in with a micrometeoroid, and has deemed the damage “uncorrectable”. Not that any damage to JWST is correctable, at least in the sense that the Hubble Space Telescope was able to be fitted with optics to fix its precisely-yet-inaccurately-ground main mirror. JWST is far too remote for a service call, so correctability in this case refers to a combination of what can be accomplished by tweaking the shape and position of the affected mirror segment, and what can be taken care of with image processing. The damage to segment C3, as well as damage to the other segments in a total of six collisions in the half year Webb has been on station, are assessed via “wavefront sensing”, which looks at how out of phase the light coming from each mirror segment is. The damage sounds bad, and it certainly must hurt for the techs and engineers who so lovingly and painstakingly built the thing to see it dinged up already, but in the long run, this damage shouldn’t hamper Webb’s long-term science goals.

In other space news, we hear that the Perseverance rover has taken its first chunk out of the ancient river delta in Jezero Crater. The rover has been poking around looking for something interesting to sample, but everything it tried out with its abrading tool was either too brittle, too hard to get at, or scientifically dull. Eventually the rover found a good spot to drill, and managed to bring up a 6.7-cm core sample. This makes the tenth core sample collected overall, and the first from the delta area, which is thought to have the best chance to contain evidence of ancient Martian life.

Closer to home, we’ve all likely heard of robotic surgery, but the image that conjures up doesn’t really comport with reality. Robot-assisted surgery is probably a better term, since surgical robots are generally just ultra-precise remote manipulators that are guided by a skilled surgeon. But if a study on surgery robot performance is any indication, the days of human surgeons might be numbered. The study compared accuracy and speed of both a human surgeon controlling a standard Da Vinci surgical robot and an autonomous version of the robot alone, using a depth camera for sensing. Using a standard surgical skills test, the autonomous system matched the human surgeons in terms of failures — thankfully, no “oopsies” for either — but bested the humans in speed and positional accuracy. It’ll probably be a while before fully autonomous surgeons are a thing, but we wouldn’t be betting against it in the long run.

Most readers will no doubt have heard the exciting news that Supercon will be back this year as an in-person event! Make sure you set aside the first weekend in November to make the pilgrimage to Pasadena — it’ll be great seeing everyone again after the long absence. But if you just can’t wait till November for an IRL con, consider dropping by SCALE 19X, coming up this week in Los Angeles. The Southern California Linux Expo is being held July 28 through 31, and features a ton of speakers, including a keynote by Vint Cerf. Hackaday readers can save 50% on tickets with promo code HACK.

And finally, as a lover of Easter eggs of all kinds, but specifically of the hidden message in software variety, we appreciated this ode to the Easter egg, the embedded artistry that has served as a creative outlet for programmers over the years. The article lists a few great examples of the art form, along with explaining why they’re actually important artifacts of the tech world and what they’re good for. We tried out a few of the ones listed in the article that we hadn’t heard of before; some hits, some misses, but they’re all appreciated. Well, most of them — the corporate rah-rah kind can bugger straight off as far as we’re concerned.