RC Telemetry Board Lets Virtual Crewmember Help You Race Better

July 30, 2026 by Donald Papp 3 Comments

Logging and telemetry in remote controlled racing is a great thing, and not only does [jwachlin]’s Open RC Spotter do a fantastic job of that, it has quite a few clever tricks up its sleeve that make it extra special.

Open RC Spotter is an ESP32-based hardware platform for high performance RC car racing that reads from various sensors (including IMU, GPS, temperature, battery, and IR receiver for IR lap beacons) to create a filtered stream of readings that include position, velocity, lap time, battery voltage, and more.

Got RC car telemetry? Feed it to a virtual race engineer for real-time feedback.

This data gets logged to an SD card, but can also be broadcast wirelessly via ESP-NOW to a receiver that can in turn send it over serial USB, or do whatever else one wishes. There’s also a neat feature that fires up a temporary WiFi access point on demand so log files can be downloaded with a web browser, no need to hook up a cable.

So far, so cool. But there’s still another nifty feature. [Update: originally the project had a link to the sim racing companion application Crew Chief. The developer clarified that at this writing, Open RC Spotter only supports its own Open RC Crew Chief application and not the similarly-named Windows sim racing assistant.] Open RC Spotter supports the Crew Chief telemetry protocol. Crew Chief is a piece of free Windows software that serves as a companion application for sim racing. It acts as a virtual race crew member, providing spoken information based on live telemetry read from supported racing sims.

Since Open RC Spotter supports the same telemetry format, one can use the virtual race engineer with RC car racing by simply feeding Open RC Spotter‘s serial data to the Crew Chief application. The RC telemetry data isn’t as rich as what comes from the racing sim APIs, but it’s more than enough to be useful.

People come up with all kinds of neat ideas when it comes to RC racing, and most of them depend on having access to good data. For example, a load cell in the steering mechanism can provides the data for force-feedback steering. We’ve even seen LiDAR and a depth camera used to automatically compute optimal racing lines.

Using Video Glasses As A Camera Viewfinder Is Harder Than It Looks

July 29, 2026 by Donald Papp 9 Comments

[John Dingley] has a Sony ZV-E10 camera that is excellent, but the design lacks a built-in electronic viewfinder. This means it relies entirely on its rear-mounted touchscreen for framing shots. This is troublesome because [John] often films in bright sunlight, and sometimes from a perspective other than normal eye level. His solution? Use a pair of XREAL video glasses as a handsfree viewfinder.

The XREAL glasses look a bit unusual, but they can be worn and used like regular sunglasses. They accept external video and importantly, allow the wearer to see the video feed while still having awareness of their surroundings. Seems like a perfect match for the camera, but as [John] discovered, there are quite a few implementation hurdles involved.

For starters, the camera and glasses do not speak the same format. The camera outputs HDMI via a distressingly fragile micro-HDMI connector, but the glasses accept video over USB-C (aka DisplayPort altmode). Connectors and cables and a converter will be involved, as well as a power bank because the glasses and converter will require a power supply. As any hacker knows, wires and connectors can eat up space very quickly.

To solve all this, [John] carefully selected off-the-shelf components chosen to minimize bulk and designed a custom camera cage to hold things cleanly without obstructing the camera’s microphone port. The end result is very tidy package that presents a single USB-C connection point between the glasses and the camera, requires no hardware modifications or soldering, and even takes the strain off the fragile connector on the ZV-E10.

The finishing touch is putting a neck strap on the XREAL glasses, allowing them to be easily donned and doffed as needed while filming. Check it out the video, embedded just below the page break.

When it comes to filming vehicles it often makes sense to film from a low perspective. The camera has a handle for this purpose, but the process is much better now that the glasses can act as a viewfinder. [John] has a soft spot for vehicles, including self-balancing unicycles or monotracks of his own design.

Continue reading “Using Video Glasses As A Camera Viewfinder Is Harder Than It Looks” →

Behold The Most Beautifully Ambitious Starship Simulator Yet

July 29, 2026 by Donald Papp 24 Comments

[Kevin Kelm] created something wondrous: Halcyon Dawn, an utterly unique and desperately challenging game that is equal parts intricate starship simulator, imposing hardware console, video game, and love letter to John Scalzi’s Old Man’s War book series. Grab a beverage for this one, because it’s chock-full of detail.

First, how is it played? The simulator represents the ship Halcyon Dawn, a stolen and renamed vessel, and the player representing its sole crew member. The ship’s new mission is to establish a home for its payload of genetically-engineered unfortunates, escaping a cruel sort of indentured military servitude. The former masters of course have a very different view of the whole situation, throwing around terms like “treason” and “theft” and in general preferring the version of the desperate protagonist they had the most control over.

Aluminum extrusion, laser-cut panels, and custom PCBs for interfacing physical controls and displays make up the bulk of the build.

As the player is meant to be operating the ship on their own, the cockpit is imposing. All 152 controls and six screens are meaningful and will be needed to pilot the Halcyon Dawn, survive hostile actions, repel boarding attempts, mine and refine vast amounts of raw materials, and in general keep the ship running and intact until an autofactory can be deployed in orbit of a suitable planet to create a new home.

All easier said than done. It’s one thing to pilot and tweak a temperamental ship, but doing so while also performing damage control and thwarting a boarding attempt by manipulating life support is quite another. Want more details? Gameplay is documented here and the physical controls have their own library.

The product of a year of focused work, [Kevin] – now retired – pointed his decades of hardware and software experience at Halcyon Dawn after realizing one night that everything he needed to create it already existed. How this whole project came to be is also a tribute to the amazing tools and equipment that hobbyists and hackers of all kinds now have to turn an idea into something that actually exists in the world. Even so, it was a load of work he is not keen to repeat. Don’t miss the technical deep-dive and photo gallery of the build.

While the game itself — being a fan-made derivative of Scalzi’s work (and useless without the custom-made hardware console) — isn’t being released, [Kevin] has shared the underlying hardware framework it is built on. Enigma is an ESP32-based set of input and output PCBs made for integrating switches, knobs, displays, relays, and more with a Python library to make them easy to work with.

Starship simulators are a wonderful subset of projects, and every one is different from the last. Something about physical builds really works for them, and while we’ve seen a camper trailer converted to starship simulator [Kevin]’s project focuses the whole experience beautifully into the single-person console you see here. Watch a video of Halcyon Dawn running in an arcade-like “attract” mode embedded just below.

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Calculator UI Is More Complex Than You Might Think

July 18, 2026 by Donald Papp 26 Comments

Calculators are so ubiquitous and so familiar that they are easy to take for granted in many different ways. [lcamtuf] points out one that has probably never occurred to many of us: the user interface for a calculator is an unexpectedly complex thing.

The internal logic to support sequential inputs and multiple operators in a way that feels intuitive is a complex thing.

Resolving something like 1 + 2 = is pretty straightforward but complexity compounds rapidly after that, with numerous special cases. Let’s imagine one decides to program a simple calculator UI as a weekend project. The development process might look a little like this:

User types in 1 + 2 = and the calculator displays 3. What happens if the user immediately presses -?
No problem, just consider the result of the previous operation as an already-there input. So we’ll have 3 - for this next operation, and wait for more.
Unless we should have treated that - as a negative sign for whatever number is coming next, making it a negative number? No, ignore that. Just treat whatever results from pressing equals as a pre-typed input.
Unless the user hits a number. Because if they hit 2 (for example) then we’ll have a 32 and not a 2 which they probably, definitely don’t expect. So that’s a special case and we should insert a clear if that happens.
Oh, better clear if the user enters a decimal, too.
I’m going to need a coffee…

And that’s just the tip of the iceberg. Imagine trying to figure all this out for the very first time, without the benefits of habit and history to fall back on.

The fact is that supporting the apparently trivial behavior of a simple calculator requires an underlying complex state machine that deals with all kinds of special cases in order to make the UI feel intuitive. And that’s just for a basic four-function calculator; we haven’t even touched on how special keys like % should behave.

We know [lcamtuf] speaks from experience, not just because of their deep knowledge of calculator history but because they rolled their own calculator that uses voltmeters as digit displays and there’s nothing like actually implementing something to make one appreciate it.

Spidery Drone Goes Near-invisible By Spinning Really, Really Fast

July 18, 2026 by Donald Papp 28 Comments

Researchers demonstrate that something interesting happens when a small drone with a spindly airframe spins at a high speed: it very nearly turns invisible. The spidery device is shown mounted in its launcher in the image above. The dark blur at the rightmost side is an outlet on the wall behind the drone, not motion blur from a moving part.

There’s not much to do about the noise, but a high-speed spin becomes nearly invisible.

It’s called the Phantom Twist, and while we’ve seen single-motor drones that spin around a central axis before, they have always incorporated a wing-like structure or cleverly leverage the magnus effect to generate lift.

There’s not a lot of detail about the Phantom Twist’s hardware design but it appears to use a downward-angled motor for lift, relying on a high-speed control system to maneuver and maintain altitude.

This does away with the need for a wing, at the cost of only being stable while rotating at a high speed. We imagine it is also a touchy design that depends greatly on being balanced just so.

A hand launcher spins the device up before releasing it for flight. The visual effect once it is up and running is pretty striking; see for yourself in the short video, embedded just below.

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Flex Filament Stuck To Your Build Platform? Reach For The Isopropanol

July 17, 2026 by Donald Papp 9 Comments

3D printing has been around long enough that everyone’s heard at least one weird trick regarding 3D prints. [Angus] of [Maker’s Muse] puts a few to the test, and came away with one solid tip for releasing TPU from a build platform to which it has unfortunately welded itself.

Flexible filaments tend to stick too well to build plates, which is why an interface layer like a thin layer of glue stick is called for. But what if one forgets to apply it before starting a print job? That can result in a print that is well and truly stuck. Peeling flex filament off a textured PEI bed is a bad time, because the print can tear and tends to leave little bits behind.

[Angus] heard that applying isopropyl alcohol helps release things in that case, so he gives it a try. Lo and behold, it seems to work! See for yourself at 18:10 in the video and keep it in mind if you end up in a similar situation. The print doesn’t exactly fall off on its own, but it does remain in one piece which is more than one can expect otherwise.

Watching isopropyl alcohol help release a stuck print is reminiscent of the way it also removes hot glue from just about any surface. The trick is getting the alcohol to wick in underneath for best results, and the same seems to be true with releasing TPU from a build plate.

One thing to keep in mind when evaluating tips and tricks from over the years is that the landscape changes. Something that maybe seemed to have potential years ago might not make much sense today. A good example is sugar as a bed adhesive, which [Angus] tries out. What started as an experiment in getting PLA to play better with glass build plates years ago doesn’t really carry over to now, with PEI-coated magnetic build platforms pretty much a solved problem. The more likely result nowadays is just a mess.

Continue reading “Flex Filament Stuck To Your Build Platform? Reach For The Isopropanol” →

Cut And Fold Your 3D Printer’s Next Cover

July 15, 2026 by Donald Papp 15 Comments

[cmh]’s ultra-simple top cover for the Snapmaker U1 3D printer has a 3D model, but don’t let that fool you. There’s no 3D printing at all involved in this project. Rather, the model is a reference shape for making an effective top cover out of cardboard or corrugated plastic sheet (also known as Coroplast) which is what [cmh] used.

The pattern can be cut from a single sheet, or from multiple pieces taped together.

Corrugated plastic is a versatile option for things like printer enclosures. It’s cheap, a good insulator, easy to cut, and available from just about any plastics supplier. We’ve made the case that they’re a good alternative to acrylic sheets for printer enclosures, but [cmh] goes even further with a design that requires no additional hardware whatsoever. Assembly doesn’t even require more than tape, really.

He provides a cutout diagram for pieces that, when assembled, make a sort of hat that is just right to cover the top of the Snapmaker U1 without obstructing the extruders. One can even lift the front panel to access the inside without removing the cover, which is a nice touch. Should one wish to add a viewing window anywhere, just cut out a square and tape a sheet of clear plastic over the hole.

For a 3D printer, an enclosure and top cover helps retain heat, block drafts, and keep dust (or curious fingers) away from the printer’s build area. The cover doesn’t need to be completely sealed to deliver those benefits, but if you do prefer your covers completely enclosed, a carefully-chosen IKEA storage box makes a conveniently great cover for the U1.