HoloLens Brings Video Game Kart Racing To Life

January 3, 2020 by Tom Nardi 12 Comments

There aren’t a lot of video game experiences we can easily recreate in the physical realm. You’ll quickly find that jumping on mushrooms in the real world doesn’t have nearly the same appeal as it does in Super Mario, and we won’t even get into the dangers of trying to recreate Frogger on your local multi-lane. But video game style go-kart racing? We have all the technology to pull that off, somebody just has to put all the pieces together.

Which is precisely what [Ian Charnas] is trying to do with his latest project. Using Microsoft’s HoloLens augmented reality headset, electric go-karts, 433 MHz wireless transceivers, and some Arduinos sprinkled in, he’s created the closest thing to Mario Kart that us flesh and blood mortals are likely to experience anytime soon.

The HoloLens headset worn by each driver overlays the necessary graphical elements like pickups and weapon effects, as well as puts over-the-top cartoon heads on the other racers. But of course, that’s only half of the story. Seeing the pickups and gadgets doesn’t do you any good if they don’t have any effect on the actual race.

To that end, [Ian] has come up with a way to control the performance of the go-karts using an electronic “backpack” that mounts to each kart. So speed boosting pickups actually make the kart go faster, and if a driver gets hit with a weapon fired at them, they get slowed down.

That’s the high-level version, anyway. There’s obviously a lot going on behind the scenes, some of which are detailed on the Hackaday.io page. One of the interesting notes is that the HoloLens needs visual markers to orient itself, which in the video after the break can be seen as black and white posters dotting the walls alongside the track. As the project progresses, [Ian] is hoping that these can be camouflaged in creative ways (such as being made to look like audience members or checkered flags) to make the overall experience more immersive.

According to [Ian], the next step is to find partners who want to help elevate this from a one-off project to something that you might actually see at an amusement park. We wish him luck, if for no other reason than we really want to play the thing ourselves. In the meantime, we’ll have to settle for racing hacked Power Wheels.

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Investigating Retroreflectors With One Heck Of A Microscope

November 4, 2019 by Lewin Day 16 Comments

Retroreflectors are interesting materials, so known for their nature of reflecting light back to its source. Examples include street signs, bicycle reflectors, and cat’s eyes, which so hauntingly pierce the night. They’re also used in the Tilt Five tabletop AR system, for holographic gaming. [Adam McCombs] got his hands on a Tilt Five gameboard, and threw it under the microscope to see how it works.

Using the ion beam, a trench was dug around the side of one of the spheres, revealing the interface between the adhesive and the sphere itself.

[Adam] isn’t mucking around, fielding a focused ion beam microscope for the investigation. This scans a beam of galium metal ions across a sample for imaging. With the added kinetic energy of an ion beam versus a more typical electron beam, the sample under the microscope can be ablated as well as imaged. This allows [Adam] to very finally chip away at the surface of the retroreflector to see how it’s made.

The analysis reveals that the retroreflecting spheres are glass, coated in metal. They’re stuck to a surface with an adhesive, which coats the bottom of the spheres, and acts as an etch mask. The metal coating is then removed from the sphere’s surface sticking out above the adhesive layer. This allows light to enter through the transparent part of the sphere, and then bounce off the metal coating back to the source, creating a sheet covered in retroreflectors.

[Adam] does a great job of describing both the microscopy and production techniques involved, before relating it to the fundamentals of the Tilt Five AR technology. It’s not the first time we’ve heard from [Adam] on the topic, and we’re sure it won’t be the last!

Tilt Five: A Fresh Take On Augmented Reality Tabletop Gaming

September 25, 2019 by Maya Posch 28 Comments

Tilt Five is an Augmented Reality (AR) system developed by Jeri Ellsworth and a group of other engineers that is aimed at tabletop gaming which is now up on Kickstarter. Though it appears to be a quite capable (and affordable at $299) system based on the Kickstarter campaign, the most remarkable thing about it is probably that it has its roots at Valve. Yes, the ones behind the Half Life games and the Steam games store.

Much of the history of the project has been covered by sites, such as this Verge article from 2013. Back then [Jeri Ellsworth] and [Rick Johnson] were working on project CastAR, which back then looked like a contraption glued onto the top of a pair of shades. When Valve chose to go with Virtual Reality instead of AR, project CastAR began its life outside of Valve, with Valve’s [Gabe] giving [Jeri] and [Rick] his blessing to do whatever they wanted with the project.

What the Tilt Five AR system looked like in its CastAR days. (credit: The Verge)

Six years later Tilt Five is the result of the work put in over those years. Looking more like a pair of protective glasses along with a wand controller that has an uncanny resemblance to a gas lighter for candles and BBQs, it promises a virtual world like one has never seen before. Courtesy of integrated HD projectors that are aimed at the retroreflective surface of the game board.

A big limitation of the system is also its primary marketing feature: by marketing it as for tabletop gaming, the fact that the system requires this game board as the projection surface means that the virtual world cannot exist outside the board, but for a tabetop game (like Dungeons and Dragons), that should hardly be an issue. As for the games themselves, they would run on an external system, with the signal piped into the AR system. Game support for the Tilt Five is still fairly limited, but more titles have been announced.

(Thanks, RandyKC)

Camera Sees Electromagnetic Interference Using An SDR And Machine Vision

April 30, 2019 by Dan Maloney 10 Comments

It’s one thing to know that your device is leaking electromagnetic interference (EMI), but if you really want to solve the problem, it might be helpful to know where the emissions are coming from. This heat-mapping EMI probe will answer that question, with style. It uses a webcam to record an EMI probe and the overlay a heat map of the interference on the image itself.

Regular readers will note that the hardware end of [Charles Grassin]’s EMI mapper bears a strong resemblance to the EMC probe made from semi-rigid coax we featured recently. Built as a cheap DIY substitute for an expensive off-the-shelf probe set for electromagnetic testing, the probe was super simple: just a semi-rigid coax jumper with one SMA plug lopped off and the raw end looped back and soldered. Connected to an SDR dongle, the probe proved useful for tracking down noisy circuits.

[Charles]’ project takes that a step further by adding a camera that looks down upon the device under test. OpenCV is used to track the probe, which is moved over the DUT manually with the help of an augmented reality display that helps track coverage, with a Python script recording its position and the RF power measurements. The video below shows the capture process and what the data looks like when reassembled as an overlay on top of the device.

Even if EMC testing isn’t your thing, this one seems like a lot of fun for the curious. [Charles] has kindly made the sources available on GitHub, so this is a great project to just knock out quickly and start mapping.

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Immersive Augmented Reality On A Budget

February 18, 2019 by Tom Nardi 6 Comments

By now we’ve all seen the cheap headsets that essentially stick a smartphone a few inches away from your face to function as a low-cost alternative to devices like Oculus Rift. Available for as little as a few dollars, it’s hard to beat these gadgets for experimenting with VR on a budget. But what about if you’re more interested in working with augmented reality, where rendered images are superimposed onto your real-world view rather than replacing it?

As it turns out, there are now cheap headsets to do that with your phone as well. [kvtoet] picked one of these gadgets up for $30 USD on AliExpress, and used it as a base for a more capable augmented reality experience than the headset alone is capable of. The project is in the early stages, but so far the combination of this simple headset and some hardware liberated from inexpensive Chinese smartphones looks to hold considerable promise for delivering a sub-$100 USD development platform for anyone looking to jump into this fascinating field.

On their own, these cheap augmented reality headsets simply show a reflection of your smartphone’s screen on the inside of the lenses. With specially designed applications, this effect can be used to give the wearer the impression that objects shown on the phone’s screen are actually in their field of vision. It’s a neat effect to be sure, but it doesn’t hold much in the way of practical applications. To turn this into a useful system, the phone needs to be able to see what the wearer is seeing.

To that end, [kvtoet] relocated a VKWorld S8 smartphone’s camera module onto the front of the headset. Beyond its relatively cost, this model of phone was selected because it featured a long camera ribbon cable. With the camera on the outside of the headset, an Android application was created which periodically flashes a bright LED and looks for reflections in the camera’s feed. These reflections are then used to locate objects and markers in the real world.

In the video after the break, [kvtoet] demonstrates how this technique is put to use. The phone is able to track a retroreflector laying on the couch quickly and accurately enough that it can be used to adjust the rendering of a virtual object in real time. As the headset is moved around, it gives the impression that the wearer is actually viewing a real object from different angles and distances. With such a simplistic system the effect isn’t perfect, but it’s exciting to think of the possibilities now that this sort of technology is falling into the tinkerer’s budget.

If you don’t want to go the DIY route, Leap Motion has been teasing an open source augmented reality headset which has us quite excited. We’re still waiting on the hardware, but that hasn’t stopped hackers from coming up with some fascinating AR applications in the meantime.

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Leap Motion’s Project North Star Gets Hardware

February 3, 2019 by Brian Benchoff 17 Comments

It’s been more than a year since we first heard about Leap Motion’s new, Open Source augmented reality headset. The first time around, we were surprised: the headset featured dual 1600×1440 LCDs, 120 Hz refresh rate, 100 degree FOV, and the entire thing would cost under $100 (in volume), with everything, from firmware to mechanical design released under Open licenses. Needless to say, that’s easier said than done. Now it seems Leap Motion is releasing files for various components and a full-scale release might be coming sooner than we think.

Leap Motion first made a name for themselves with the Leap Motion sensor, a sort of mini-Kinect that only worked with hands and arms. Yes, we’re perfectly aware that sounds dumb, but the results were impressive: everything turned into a touchscreen display, you could draw with your fingers, and control robots with your hands. If you mount one of these sensors to your forehead, and reflect a few phone screens onto your retinas, you have the makings of a stereoscopic AR headset that tracks the movement of your hands. This is an over-simplified description, but conceptually, that’s what Project North Star is.

The files released now include STLs of parts that can be 3D printed on any filament printer, files for the electronics that drive the backlight and receive video from a laptop, and even software for doing actual Augmented Reality stuff in Unity. It’s not a complete project ready for prime time, but it’s a far cry from the simple spec sheet full of promises we saw in the middle of last year.

Smartphone App Uses AR To Visualize The RF Spectrum

January 9, 2019 by Dan Maloney 21 Comments

Have you ever wished you could see in the RF part of the radio spectrum? While such a skill would probably make it hard to get a good night’s rest, it would at least allow you to instantly see dead spots in your WiFi coverage. Not a bad tradeoff.

Unwilling to go full [Geordi La Forge] to be able to visualize RF, [Ken Kawamoto] built the next best thing – an augmented-reality RF signal strength app for his smartphone. Built to aid in the repositioning of his router in the post-holiday cleanup, the app uses the Android ARCore framework to figure out where in the house the phone is and overlays a color-coded sphere representing sensor data onto the current camera image. The spheres persist in 3D space, leaving a trail of virtual breadcrumbs that map out the sensor data as you warwalk the house. The app also lets you map Bluetooth and LTE coverage, but RF isn’t its only input: if your phone is properly equipped, magnetic fields and barometric pressure can also be AR mapped. We found the Bluetooth demo in the video below particularly interesting; it’s amazing how much the signal is attenuated by a double layer of aluminum foil. [Ken] even came up with an Arduino with a gas sensor that talks to the phone and maps the atmosphere around the kitchen stove.

The app is called AR Sensor and is available on the Play Store, but you’ll need at least Android 8.0 to play. If your phone is behind the times like ours, you might have to settle for mapping your RF world the hard way.

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