Re-imagining Telepresence With Humanoid Robots And VR Headsets

July 30, 2024 by Donald Papp 20 Comments

Don’t let the name of the Open-TeleVision project fool you; it’s a framework for improving telepresence and making robotic teleoperation far more intuitive than it otherwise would be. It accomplishes this in part by taking advantage of the remarkable technology packed into modern VR headsets like the Apple Vision Pro and Meta Quest. There are loads of videos on the project page, many of which demonstrate successful teleoperation across vast distances.

Teleoperation of robotic effectors typically takes some getting used to. The camera views are unusual, the limbs don’t move the same way arms do, and intuitive human things like looking around to get a sense of where everything is don’t translate well.

A stereo camera with gimbal streaming to a VR headset complete with head tracking seems like a very hackable design.

To address this, researches provided a user with a robot-mounted, real-time stereo video stream (through which the user can turn their head and look around normally) as well as mapping arm and hand movements to humanoid robotic counterparts. This provides the feedback to manipulate objects and perform tasks in a much more intuitive way. In short, when our eyes, bodies, and hands look and work more or less the way we expect, it turns out it’s far easier to perform tasks.

The research paper goes into detail about the different systems, but in essence, a stereo depth and RGB camera is perched with a 3D printed gimbal atop a humanoid robot frame like the Unitree H1 equipped with high dexterity hands. A VR headset takes care of displaying a real-time stereoscopic video stream and letting the user look around. Hand tracking for the user is mapped to the dexterous hands and fingers. This lets a person look at, manipulate, and handle things without in-depth training. Perhaps slower and more clumsily than they would like, but in an intuitive way all the same.

Interested in taking a closer look? The GitHub repository has the necessary code, and while most of us will never be mashing ADD TO CART on something like the Unitree H1, the reference design for a stereo camera streaming to a VR headset and mirroring head tracking with a two-motor gimbal looks like the sort of thing that would be useful for a telepresence project or two.

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Undersea Cable Repair

July 30, 2024 by Dan Maloney 6 Comments

The bottom of the sea is a mysterious and inaccessible place, and anything unfortunate enough to slip beneath the waves and into the briny depths might as well be on the Moon. But the bottom of the sea really isn’t all that far away. The average depth of the ocean is only about 3,600 meters, and even at its deepest, the bottom is only about 10 kilometers away, a distance almost anyone could walk in a couple of hours.

Of course, the problem is that the walk would be straight down into one of the most inhospitable environments our planet has to offer. Despite its harshness, that environment is home to hundreds of undersea cables, all of which are subject to wear and tear through accidents and natural causes. Fixing broken undersea cables quickly and efficiently is a highly specialized field, one that takes a lot of interesting engineering and some clever hacks to pull off.

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Junk Bin Build Lets You Test Fuel Injectors On The Cheap

July 30, 2024 by Dan Maloney 32 Comments

Fiddle around with cars long enough and you’ll realize two things: first, anything beyond the simplest repairs will probably require some kind of specialized tool, and second, those tools can be prohibitively expensive. That doesn’t mean you’re out of luck, though, especially if you’ve got scrap galore and a DIY spirit, as this junk bin fuel injector test stand ably demonstrates.

[Desert Rat Racer]’s test rig is designed to support four injectors at once and to test them under conditions as close as possible to what they’ll experience when installed. To that end, [Rat] mounted a junk intake manifold to a stand made from scrap wood and metal found by the side of the road. A pickle jar serves as a reservoir for the test fluid — he wisely used mineral spirits as a safer substitute for gasoline — and a scrap electric fuel pump pressurizes a junk fuel rail, which distributes fuel to the injectors under test.

For testing, the injectors are wired up to an electric injector tester, which is one of the few off-the-shelf components in the build. The fuel pump and injectors are powered by the 12 volt rail of a scrapped PC power supply. Just being able to watch the spray pattern is often enough to find a faulty injector, but in case a more quantitative test is indicated, each injector is positioned over a cheap glass cylinder to catch the test fluid, and scraps of a tape measure are used to measure the depth of the collected fluid. No fancy — and expensive — graduated cylinders required.

While we truly respect the hackiness of [Desert Rat Racer]’s build, the concept of avoiding buying tactical tools is foreign to us. We understand the logic of not dropping a ton on a single-use tool, but where’s the fancy blow-molded plastic case?

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Building The Unreleased Lemmings Arcade Cabinet From 1991

July 29, 2024 by Maya Posch 7 Comments

Back in the early 90s the world was almost graced with an arcade version of Lemmings, but after a few board revisions it was abandoned in 1991. Now the folk over at UK-based [RMC – The Cave] on YouTube have managed to not only get their mitts on a nearly finished prototype board, but have also designed and built a period-appropriate cabinet to go with it. This involved looking at a range of arcade cabinets created by Data East and picking a design that would allow both for the two-player mode of the game, and fit the overall style.

Arcade cabinets came in a wide range of cabinet styles and control layouts, largely defined by the game’s requirements, but sometimes with flourishes to distinguish the cabinet from the hundred others in the same arcade.

In this particular case the typical zig-zag (Z-back) style was found to be a good fit as on the Data East Night Slashers 1993-era cabinet, which then mostly left the controls (with two trackballs) and cabinet art to figure out. Fortunately there is plenty of inspiration when it comes to Lemmings art, leading to the finished cabinet with the original mainboard, the JAMMA wiring harness with MultiPi JAMMA controller, a 19″ CRT monitor and other components including the 3D printed controls panel.

With more and more new arcades popping up in the US and elsewhere, perhaps we’ll see these Lemmings arcade cabinets appear there too, especially since the ROMs on the prototype board were dumped for convenient MAME-ing.

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Three different keyboard devices with greyscale LCDs on top are on a white table. In the back left is a beige one with grey keys, front and center is a black model, and to the right is a translucent blue model with black keys being held up by a hand.

A Brief History Of AlphaSmart

July 29, 2024 by Navarre Bartz 18 Comments

There are a handful of gadgets that do one thing so well that they become cult classics long after the company that made them has moved on or closed up shop. [This Does Not Compute] takes us through the history of the AlphaSmart word processor which started as an educational tool, but finds itself in many a writer’s bag today.

The original AlphaSmart bears more than a passing resemblance to its Apple contemporaries since the company was founded by two Apple engineers. The Cupertino company didn’t see the value in the concept, but didn’t lean on any non-competes to keep the pair from pursuing the idea on their own time either. What resulted was a dead simple word processor that could be had for 1/5 of what a new computer typically cost in the era, which was particularly attractive for the target market of schools.

After several successful years, the pressure of PDAs and then smartphones from one side and cheaper laptops from the other meant school districts no longer wanted single-purpose devices when they could have a fully-fledged computing experience for students. We wonder if that was the right call, with so many now wanting distraction-free devices, but it was the end of the road for the company either way.

Our own [Kristina Panos] and [Tom Nardi] have shown us the guts of the Neo and of one of its competitors, the Writer, respectively. If you have a Neo of your own in need of replacement keycaps, you can print them.

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A Soviet Cassette Recorder Receiving Some Love

July 29, 2024 by Jenny List 40 Comments

For those of us who lived in the capitalist west during the Cold War, there remains a fascination to this day about the Other Side. The propaganda we were fed as kids matched theirs in describing the awful things on the other side of the wall, something that wasn’t borne out when a decade or so later in the 1990s we met people from the former communist side and found them unsurprisingly to be just like us. It’s thus still of interest to have a little peek into Eastern Bloc consumer electronics, something we have the chance of courtesy of [DiodeGoneWild], who’s fixing a 1980s Soviet cassette recorder.

The model in question is a Vesna 309, and it has some audio issues and doesn’t turn the tape. It gets a teardown, the motor is cleaned up inside, and a few capacitor and pot cleanups later it’s working again. But the interest lies as much in the machine itself as it does in the repair, as it’s instructive to compare with a Western machine of the same period.

We’re told it would have been an extremely expensive purchase for a Soviet citizen, and in some ways such as the adjustable level control it’s better-specified than many of our equivalents. It’s based upon up-to-date components for its era, but the surprise comes in how comparatively well engineered it is. A Western cassette deck mechanism would have been a much more sketchy affair than the substantial Soviet one, and its motor would have been a DC part with a simple analogue speed controller rather than the brushless 3-phase unit in the Vesna. Either we’re looking at the cassette deck for senior comrades only, or the propaganda was wrong — at least about their cassette decks. The full video is below, and if you’re hungry for more it’s not the first time we’ve peered into electronics from the eastern side of the Iron Curtain.

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An RC Tracked Robot, Without The Pain

July 28, 2024 by Jenny List 13 Comments

Small robots can be found at all levels from STEM toys for kids all the way through to complex hacker projects. Somewhere along that line between easy enough for anyone to build and interesting enough for hackers lies the PlayCar, from [ComfySpace]. It’s a small build-it-yourself tracked robot that’s controlled from your smartphone via an app.

At the PlayCar’s heart is a Raspberry Pi Zero 2W, and surrounding it are a set of inexpensive off the shelf modules for power and motor control. The juice meanwhile comes from a set of AA batteries, and the motors are geared DC units. Having acquired all the components, the 3D printable parts can then be downloaded from Printables, and the ComfySpace app can be downloaded for either Apple or Android platforms.

It’s clear that ComfySpace is a start-up targeting the education sector, and we wish them every success. The approach of making an open platform is one we like, as it has the potential to create a community feeding back designs and add-ons rather than remaining proprietary. You can take a look at the video below the break for more information.

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