Programming Robots Is Hard, Figuring Out How To Make It Easier Is Harder

June 18, 2024 by Donald Papp 12 Comments

[Benjie Holson] is an experienced roboticist and wrote an interesting article published on IEEE Spectrum about how the idea most people have of non-roboticists is a myth, and efforts to target this group with simplified robotic frameworks tend to be doomed.

Now, let’s make a couple things absolutely clear right up front: He is not saying robots shouldn’t be easier to program, nor is he saying that non-roboticists literally do not exist (of course they do.) The issues he’s highlighting really come down to product design.

[Benjie] points out that programming robots is super hard, but it’s also hard in more than one way and for more than one reason. And when people try to create a product to make it easier, they tend to commit two big product design no-no’s: they focus on the wrong hard parts, and they design their product for a vaguely-defined audience that doesn’t really exist. That group is the mythical non-roboticist.

These are actually very solid points to make in terms of product design in general. Designing a product that solves the wrong problems for a poorly-defined group isn’t exactly a recipe for success. [Benjie]’s advice on making a truly effective and useful API framework that genuinely lowers the bar of complexity in a useful way is similarly applicable to product design in general.

His first piece of advice is not to design for poorly-defined amorphous groups. Your product should serve actual needs of actual users. If you cannot name three people you have actually spoken to who would be helped by your product, you are designing for an amorphous (and possibly imaginary) group.

The second is to design as though your users are just as smart as you are, just less tolerant of problems stemming from rough edges like compatibility and configuration issues. Remove those so that your users can get useful work done without having to re-invent the wheel, or resort to workarounds.

Robotic frameworks like ROS are useful and extensible, but whenever someone attempts to focus on creating a simplified framework, [Benjie] says they tend to step on the same rakes. It’s a mistake [Benjie] has committed himself, and see repeated by others. We think his advice is good product design advice in general, whether for designing APIs or something else.

The Guinness Brewery Invented One Of Science’s Most Important Statistical Tools

June 18, 2024 by Donald Papp 12 Comments

The Guinness brewery has a long history of innovation, but did you know that it was the birthplace of the t-test? A t-test is usually what underpins a declaration of results being “statistically significant”. Scientific American has a fascinating article all about how the Guinness brewery (and one experimental brewer in particular) brought it into being, with ramifications far beyond that of brewing better beer.

William Sealy Gosset (aka ‘Student’), self-trained statistician. [source: user Wujaszek, wikipedia]

Head brewer William Sealy Gosset developed the technique in the early 1900s as a way to more effectively monitor and control the quality of stout beer. At Guinness, Gosset and other brilliant researchers measured everything they could in their quest to optimize and refine large-scale brewing, but there was a repeated problem. Time and again, existing techniques of analysis were simply not applicable to their gathered data, because sample sizes were too small to work with.

While the concept of statistical significance was not new at the time, Gosset’s significant contribution was finding a way to effectively and economically interpret data in the face of small sample sizes. That contribution was the t-test; a practical and logical approach to dealing with uncertainty.

As mentioned, t-testing had ramifications and applications far beyond that of brewing beer. The basic question of whether to consider one population of results significantly different from another population of results is one that underlies nearly all purposeful scientific inquiry. (If you’re unclear on how exactly the t-test is applied and how it is meaningful, the article in the first link walks through some excellent and practical examples.)

Dublin’s Guinness brewery has a rich heritage of innovation so maybe spare them a thought the next time you indulge in statistical inquiry, or in a modern “nitro brew” style beverage. But if you prefer to keep things ultra-classic, there’s always beer from 1574, Dublin castle-style.

Intentionally Overly-Complex Clock Is Off To A Good Start

June 3, 2024 by Donald Papp 1 Comment

[Kelton] from Build Some Stuff decided to create a clock that not only had kinetic elements, but a healthy dose of Rube Goldberg inspiration. The result is a work in progress, but one that looks awfully promising.

The main elements of the design are rotating pieces that indicate the hours and minutes, but each hour is advanced solely by the satisfying physical culmination of multiple interacting systems. Those systems also completely reset themselves every hour.

Each hour, a marble run kicks off a short chain reaction that culminates in advancing the hour.

At the top of the hour, a marble starts down a track and eventually tips over a series of hinged “dominoes”, which culminate in triggering a spring-loaded ratchet that advances the hour. The marble then gets carried back to the top of the device, ready for next time. Meanwhile, the domino slats and spring-loaded ratchets all get reset by a pulley system.

There’s still some work to do in mounting the motor, pulley system, and marble run. Also, a few bugs have surfaced, like a slight overshoot in the hour display. All par for the course for a device with such a large number of moving parts, we suppose.

[Kelton] has a pretty good sense how it will all work in the end, and it looks promising. We can’t wait to see it in its final form, but the tour of clock so far is pretty neat. Check it out in the video, embedded just under the page break.

As for the clock’s inspiration, Rube Goldberg’s cultural impact is hard to overstate and our own Kristina Panos has an excellent article about the man that might just teach you something you didn’t know.

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Make A Super Cute LiDAR Measurement Module

June 2, 2024 by Donald Papp 10 Comments

This ultra-cute tiny LiDAR rangefinder project by [gokux] can be thought of as a love letter to the incredible resources and components hobbyists and hackers of all types have access to nowadays. In fact, it all stemmed from coming across a miniscule half-inch 64×32 OLED display module that was simply too slick to pass up.

USB connector for charging on the bottom, hole for distance sensor out the top.

To use it, one simply powers it on and the display will read out the distance in millimeters. The VL53L0X time-of-flight sensor inside works by sending out a laser pulse and measuring how long it takes for the pulse to bounce back. We hope you’re curious about what such a sensor looks like on the inside, because here’s a nifty teardown of these fantastic devices. The device can technically measure distances of up to 2 m, but [gokux] says accuracy drops off after 1 m.

The main components besides the OLED display and VL53L0X sensor are an ESP32-C3 board (which handily integrates battery charging circuitry), 3D-printed enclosure, tiny rechargeable battery, and power switch. The whole thing is under one cubic inch. Not bad, and it even makes a passable keychain. Parts list, code, and 3D model files, including STEP format, are all available if you’d like to spend an afternoon making your own.

How To Cram 945 LEDs Into A Teeny Tiny Vegas-Style Sphere

May 31, 2024 by Donald Papp 18 Comments

[Carl Bugeja] finds the engineering behind the Las Vegas Sphere fascinating, and made a video all about the experience of designing and building a micro-sized desktop version. [Carl]’s version is about the size of a baseball and crams nearly a thousand RGB pixels across the surface.

A four-layer flexible PCB is the key to routing data and power to so many LEDs.

Putting that many addressable LEDs — even tiny 1 mm x 1 mm ones — across a rounded surface isn’t exactly trivial. [Carl]’s favored approach ended up relying on a flexible four-layer PCB and using clever design and math to lay out an unusual panel shape which covers a small 3D printed geodesic dome.

Much easier said that done, by the way. All kinds of things can and do go wrong, from an un-fixable short in the first version to adhesive and durability issues in later prototypes. In the end, however, it’s a success. Powered over USB-C, his mini “sphere” can display a variety of patterns and reactive emojis.

As elegant and impressive as the engineering is in this dense little display, [Carl] has some mixed feelings about the results. 945 individual pixels on such a small object is a lot, but it also ends up being fairly low-resolution in the end. It isn’t very good at displaying sharp lines or borders, so any familiar shapes (like circles or eyes) come out kind of ragged. It’s also expensive. The tiny LEDs may be only about 5 cents each, but when one needs nearly a thousand of them for one prototype that adds up quickly. The whole bill of materials comes out to roughly $250 USD after adding up the components, PCB, controller, and mechanical parts. It’s certainly a wildly different build than its distant cousin, the RGB cube.

Still, it’s an awfully slick little build. [Carl] doubts there’s much value in pursuing the idea further, but there are plenty of great images and clips from the build. Check out the video, embedded below.

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Tell Time And Predict The Heavens With This Astronomical Timepiece

May 31, 2024 by Donald Papp 2 Comments

Looking for a new project, or just want to admire some serious mechanical intricacy? Check out [illusionmanager]’s Astronomical Clock which not only tells time, but shows the the positions of the planets in our solar system, the times of sunrise and sunset, the phases of the moon, and more — including solar and lunar eclipses.

One might assume that the inside of the Astronomical Clock is stuffed with a considerable number of custom gears, but this is not so. The clock’s workings rely on a series of tabs on movable rings that interact with each other to allow careful positioning of each element. After all, intricate results don’t necessarily require complex gearing. The astrolabe, for example, did its work with only a few moving parts.

The Astronomical Clock’s mechanical elements are driven by a single stepper motor, and the only gear is the one that interfaces the motor shaft to the rest of the device. An ESP32-C3 microcontroller takes care of everything else, and every day it updates the position of each element as well as displaying the correct time on the large dial on the base.

The video below shows the clock in operation. Curious its inner workings? You can see the entire construction process from beginning to end, too.

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The Secret Behind The Motion Of Microsoft’s Bendy Mouse

May 25, 2024 by Donald Papp 7 Comments

The Surface Arc is a designed-for-travel mouse that carries flat, but curves into shape for use. It even turns on when it’s bent and shuts itself off when it’s flat. The device isn’t particularly new, but [Mr Teardown] was a bit surprised at the lack of details about what’s inside so tears it down in a video to reveal just how the mechanism works.

The mechanism somewhat resembles a beaver’s tail, and locks into place thanks to a magnetic connector at the base that holds the device’s shape.

The snap-action of the bending is accomplished with the help of a magnetic connection near the bottom end of the mouse’s “tail”, locking it into place when flexed. Interestingly, the on and off functionality does not involve magnets at all. Power control is accomplished by a little tab that physically actuates a microswitch.

There are a few interesting design bits that we weren’t expecting. For example, there is no mechanical scroll wheel. The mouse delivers similar functionality with touch sensors and a haptic feedback motor to simulate the feel and operation of a mechanical scroll wheel.

[Mr Teardown] finds the design elegant and effective, but we can’t help but notice it also seems perhaps not as optimized as it could be. There are over 70 components in all, including 23 screws (eight different kinds!), and it took [Mr Teardown] the better part of 45 minutes to re-assemble it. You can watch the entire teardown in the video embedded just under the page break; it’s a neat piece of hardware for sure.

If you’re in the mood for another mouse teardown, we have a treat for you: an ancient optical mouse from the 80s that required a special surface to work.

[via Core77]

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