Inviting The Public To Take Stereo Photos For Science

September 20, 2024 by Al Williams 14 Comments

[Lynnadeng]’s team wanted to monitor the Los Angeles River over time and wanted citizen scientists — or anyone, for that matter — to help. They built a dual phone holder to allow random passersby to use their phones to take photos. A QR code lets them easily send the pictures to the team. The 3D printed holder is fixed in place and has a known gap that allows stereo reconstruction from pairs of photos.

Of course, people aren’t going to know what to do, so you need a sign with instructions along with the QR code. One advantage to this scheme is that it’s cheap. All the camera hardware is in the public’s phone. Of course, you still have to make the holder robust to the elements, but that’s not nearly as difficult as supplying power and weatherproofing cameras and radios.

The real interesting part is the software. At first, we were disappointed that the post had a dead link to GitHub, but it was easy enough to find the correct one. In some cases, people will use a single camera, so 3D reconstruction isn’t always possible.

We love citizen science around here. No matter where you live, there are many opportunities to contribute.

Inside A Portable Satellite Dish

September 19, 2024 by Al Williams 22 Comments

Like many of us, [Gabe] has things he just can’t stop buying. In his case, it is portable satellite dishes. You’ve seen these. They look like a dome or maybe a hard hat on some kind of motorized base. What’s in them? What can you do with them? Watch the video below and find out.

As [Gabe] points out, you can often find these on the surplus market for very little money. You can sometimes find them on the side of the road for free, too. Although we’ve never been that lucky.

The video shows three generations of Winegard antennas. It shows what’s inside and how to command them. Of course, the obvious use for these is as an antenna. But we also were thinking they’d make a fair motion base for something, too.

Some of the antennas lack any limit switches. On startup, the system spins until it grinds the plastic gears to find its travel limits. We expect that’s not good for the gears, but it does work. [Gabe] mentions it might be a bit of planned obsolescence, but we imagine it is more of a cost-saving measure.

Junkyards are a frequent source for satellite gear, apparently. Dishes have lots of other uses, too.

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Design And The Golden Rule

September 19, 2024 by Al Williams 36 Comments

You often learn the golden rule or some variation of it as early as kindergarten. There are several ways to phrase it, but you most often hear: “Do unto others as you would have them do unto you.” While that’s catchy, it is really an aphorism that encourages us to consider the viewpoints of others. As people who design things, this can be tricky. Sometimes, what you want isn’t necessarily what most people want, and — conversely — you might not appreciate what most people want or need.

EDIT/1000

I learned this lesson many years ago when I used to babysit a few HP/1000 minicomputers. Minicomputer sounds grand, but, honestly, a Raspberry Pi of any sort would put the old HP to shame. Like a lot of computers in those days, it had a text editor that was arcane even by the standards of vi or emacs. EDIT/1000 couldn’t be sure you weren’t using a printing terminal, and the commands reflect that.

For example, printing a few lines around the current line requires the command: “/-2,L,5” which isn’t that hard, I suppose. To delete all lines that contain a percent sign, “1$ D/%/A/” assuming you don’t want to be asked about each deletion.

Sure, sure. As a Hackaday reader, you don’t find this hard to puzzle out or remember. But back in the 1980s, a bunch of physicists and chemical engineers had little patience for stuff like that. However, the editor had a trick up its sleeve.

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A Guide To Laser Cutting Metal, If You’ve Got The Cash

September 19, 2024 by Al Williams 9 Comments

While many of us now have laser cutters — either a K40-style machine or one of the newer high-output diodes — you probably don’t have one that cuts metal. True, some hobby lasers now offer IR laser heads with modest power to engrave metal. The xTool S1, for example, accepts a 2 W IR laser as an option, but we doubt it would cut through anything thicker than foil. However, there are a growing number of fiber and carbon dioxide lasers that can cut metal at semi-reasonable prices, and [All3DP] has a primer on the technology that is worth a read.

According to the post, CO₂ lasers are less expensive but require gas assist, can’t work with shiny metals well, and are finicky because of the mirrors and glass tube inside. Fiber lasers cost more, but don’t need gas, work on more materials, and have fewer parts that need maintenance or may be prone to damage. There are other kinds of lasers, but the post focuses on these, the most common ones.

Machines that can cut metal aren’t cheap. They start at about $10,000. However, prices are dropping and we remember when $10,000 would buy you what would today be a terrible oscilloscope, so maybe there’s hope for an impulse-buy metal-cutting laser one day.

It isn’t that diode lasers can’t cut metal at all, but the results are not terribly useful. What would you rather have? A metal cutter or a metal 3D printer?

Airline Seats Are For Dummies

September 18, 2024 by Al Williams 9 Comments

You normally don’t think a lot would go into the construction of a chair. However, when that chair is attached to a commercial jet plane, there’s a lot of technology that goes into making sure they are safe. According to a recent BBC article, testing involves crash dummies and robot arms.

Admittedly, these are first-class and business-class seats. Robots do repetitive mundane tasks like opening and closing the tray table many, many times. They also shoot the seats with crash dummies aboard at up to 16 Gs of acceleration. Just to put that into perspective, a jet pilot ejecting gets about the same amount of force. A MiG-35 pilot might experience 10 G.

We didn’t realize how big the airline seat industry is in Northern Ireland. Thompson, the company that has the lab in question, is only one of the companies in the country that builds seats. Apparently, the industry suffered from the global travel slowdown during the pandemic but is now bouncing back.

While people worry about robots taking jobs, we can’t imagine anyone wanting to spend all day returning their tray table to the upright and locked position repeatedly. We certainly don’t want to be 16 G crash dummies, either.

Crash dummies have a long history, of course. Be glad airliners don’t feature ejector seats.

From High Level Language To Assembly

September 18, 2024 by Al Williams 24 Comments

If you cut your teeth on Z-80 assembly and have dabbled in other assembly languages, you might not find much mystery in creating programs using the next best thing to machine code. However, if you have only used high level languages, assembly can be somewhat daunting. [Shikaan] has an introductory article aimed to get you started at the “hello world” level of x86-64 assembly language. The second part is already up, too, and covers control structures.

You can argue that you may not need to know assembly language these days, and we’ll admit it’s certainly not as important as it used to be. However, there are unusual cases where you really need either the performance or the small footprint, which is only possible in assembly language. What’s more, it is super useful to be able to read assembly from your high-level tools when something goes wrong.

Of course, one of the problems is that each assembly language is different. For example, knowing that the x86 assembly doesn’t completely transfer to ARM instructions. However, in most cases, the general concepts apply, and it is usually fairly easy to learn your second, third, or fourth instruction set.

We’ve had our own tutorials on this topic. You can also debate if you should learn assembly first or wait, although in this case, the audience is people who waited.

Hack Your Eyesight With High Tech Bifocals

September 16, 2024 by Al Williams 32 Comments

As we get older, our eyes get worse. That’s just a fact of life. It is a rite of passage the first time you leave the eye doctor with a script for “progressive” lenses which are just fancy bifocals. However, a new high-tech version of bifocals promises you better vision, but with a slight drawback, as [Sherri L. Smith] found.

Remember how users of Google Glass earned the nickname “glassholes?” Well, these new bifocals make Google Glass look like a fashion statement. If you are too young to need them, bifocals account for the fact that your eyes need different kinds of help when you look close up (like soldering) or far away (like at an antenna up on a roof). A true bifocal has two lenses and you quickly learn to look down at anything close up and up to see things far away. Progressives work the same, but they transition between the two settings instead of having a discrete mini lens at the bottom.

The new glasses, the ViXion01 change based on what you are looking for. They measure range and adjust accordingly. For $555, or a monthly rental, you can wear what looks like a prototype for a Star Trek visor and let it deduce what you are looking at and change its lenses accordingly.

Of course, this takes batteries that last about ten hours. It also requires medical approval to be real glasses and it doesn’t have that, yet. Honestly, if they worked well and didn’t look so dorky, the real use case might be allowing your eye doctor to immediately download a new setting as your vision changes. How about you? How much odd headgear are you willing to wear in public and why?

Glasses have a long strange history. While a university prototype we saw earlier was not likely to win fashion awards, they did look better than these. Maybe.