HoloLens Brings Video Game Kart Racing To Life

January 3, 2020 by 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.

Continue reading “HoloLens Brings Video Game Kart Racing To Life” →

A Programming Language That Lets You Code With Pixels

January 3, 2020 by 23 Comments

This programming language gives you programs that resemble modern art. It’s fortunately a feature of the language, dubbed Piet after the famed abstract painter Piet Mondrian.

The language uses 20 distinct colors, with the colors cycling from red to yellow to green to cyan to blue to magenta and the lightness cycling from light to normal to dark. The code is formed from graphics made of the recognized colors, with individual pixels holding much of the information. Stacks are used for storing data values, that can exist as integers or as Unicode characters with the proper commands applied.

Numbers in the program are represented by colors, while black blocks indicates edges and white blocks indicate free zones. The interpreter physically slides through blocks in the direction of the Direction Pointer (DP), with hue changes indicating different commands based on the steps of the change.

To execute a program, the Piet language interpreter begins in the upper left codel (or individual code block) of the program, maintaining a DP initially pointed to the right and a Codel Chooser (CC) initially pointed to the left. The DP and CC turn right, left, down, or up depending on the execution.

There is currently a small community of coders developing sample programs, interpreters, IDEs, and compilers for the language. You can check out some of the sample programs here.

Prolific Videos Show Altair 8800 Recreation

January 2, 2020 by 24 Comments

The January 1975 issue of Popular Electronics introduced the Altair 8800 and hit the newsstands in December of 1974, so it is only natural that around the New Year people start thinking about the old computer. [Shadowtron] did more than think about it. He ordered some replica PCBs and is building a new one. Even better, he’s posted an amazing number of videos (up to number 56 as I write this) detailing his progress. You can find part 1, below.

The boards are from Trailing Edge Technology. There’s a backplane board (about $100) as well as a few boards to fit it available for about $30 each — unpopulated, of course.

Continue reading “Prolific Videos Show Altair 8800 Recreation” →

LC Oscillators, Animated

January 2, 2020 by 23 Comments

We wish that all the beautiful animations that are available today to understand math and electronics had been around when we were in school. Nonetheless, they are there for today’s students and [Learn Engineering] has another gorgeous one covering LC oscillation. Check it out, below.

If you are thoroughly grounded — no pun intended — in LC circuits, you probably won’t learn anything new. However, the animations are worth watching, just to admire them, if nothing else.

Continue reading “LC Oscillators, Animated” →

A Wireless Method For Pressing Tofu

January 2, 2020 by 47 Comments

Tofu is a fairly common food in East and Southeast Asian cuisines, but it has also been making its way around vegetarian circles as a meat substitute. While it may be a more environmentally friendly source of protein than meat, it does have the unfortunate side effect of being fairly tedious to cook. To reach the right consistency, tofu requires hours of pressing to drain excess water, which tends to be tedious for most amateur cooks.

A team of students at HackMIT developed a contraption that incrementally presses tofu for you, using signals sent over WiFi to initialize the device. Several 3D-printed components extend an existing food container, along with a stepper motor, motor shield, Adafruit Feather HUZZAH, and a screen.

The motor steps at a rate of 30rpm once a signal is sent from a mobile application, causing four connected threaded rods to begin rotating. The tofu tray travels upwards to press against its lid, draining out excess water. A central gear box containers complementary cutouts that allow the tofu platform to travel vertically when shafts are rotated, pushed by nuts below the platform. The students also included a screen indicating time remaining, as well as a notification sent to the user once the tofu is finished being pressed.

It’s certainly a useful solution that will hopefully increase the popularity of tofu-based recipes!

DIY Trommel Sifts Compost In Style

January 2, 2020 by 22 Comments

Composting is a great idea that helps you and the planet at the same time. But all that stuff is going to break down at different rates, and depending on what you put in there and how soon you want to use the compost, you’ll probably have to sift out some unwanted stuff first.

[Minnear Knives] had a bunch of apricot stones in his compost pile, and it was the pits. He did some research and decided to build his own rotary trommel to tumble out the trash. As you will see in the video after the break, it works really well. All he has to do is turn on the motor and shovel raw compost or dirt into one end. Bad stuff tumbles out the other end into a wheelbarrow, while the good stuff is sifted down into a pile under the cylinder. Just look at that rich, fluffy compost.

The best part is that he was able to make it mostly from stuff he had lying around, though he did trade some beer for the v-belt pulley. The cylinder is essentially made from mesh that’s zip-tied to bicycle rims. A 1/4 horsepower motor mounted up top uses that v-belt pulley to spin the cylinder’s rims against casters that are mounted to the frame. Thanks to the pair of bike wheels on the back, he can cart it around the ranch unassisted.

Composting doesn’t have to be any more difficult than a pile in the backyard. But if you don’t have a backyard, why not build a rotating bin that you can monitor from your phone?

Continue reading “DIY Trommel Sifts Compost In Style” →

Assistive Technolgy Switch Is Actuated Using Your Ear Muscles

January 2, 2020 by 16 Comments

Assistive technology is extremely fertile ground for hackers to make a difference, because of the unique requirements of each user and the high costs of commercial solutions. [Nick] has been working on Earswitch, an innovative assistive tech switch that can be actuated using voluntary movement of the middle ear muscle.

Most people don’t know they can contract their middle ear muscle, technically called the tensor tympani, but will recognise it as a rumbling sound or muffling effect of your hearing when yawning or tightly closing eyes. Its function is actually to protect your hearing from loud sounds screaming or chewing. [Nick] ran a survey and found that 75% can consciously contract the tensor tympani and 17% of can do it in isolation from other movements. Using a cheap USB auroscope (an ear camera like the one [Jenny] reviewed in November), he was able to detect the movement using iSpy, an open source software package meant for video surveillance. The output from iSpy is used to control Grid3, a commercial assistive technology software package. [Nick] also envisions the technology being used as a control interface for consumer electronics via earphones.

With the proof of concept done, [Nick] is looking at ways to make the tech more practical to actually use, possibly with a CMOS camera module inside a standard noise canceling headphones. Simpler optical sensors like reflectance or time-of-flight are also options being investigated. If you have suggestions for or possible use case, drop by on the project page.

Assistive tech always makes for interesting hacks. We recently saw a robotic arm that helps people feed themselves, and the 2017 Hackaday Prize has an entire stage that was focused on assistive technology.