Delicious Vector Game Console Runs Pac-Man, Tetris, And Mario

December 26, 2018 by 20 Comments

The only question we have about [mitxela]’s DIY vector graphics game console is: Why did he wait five years to tell the world about it?

Judging by the projects we’ve seen before, from his tiny LED earrings to cramming a MIDI synthesizer into both a DIN plug and later a USB plug, [mitxela] likes a challenge. And while those projects were underway, the game console you’ll see in the video below was sitting on the shelf, hidden away from the world. That’s a shame, because this is quite a build.

Using a CRT oscilloscope in X-Y mode as a vector display, the console faithfully reproduces some classic games, most of which, curiously enough, were not originally vector games. There are implementations of the Anaconda, RetroRacer, and AstroLander minigames from Timesplitter 2. There are also versions of Pac-Man, Tetris, and even Super Mario Brothers. Most of the games were prototyped in JavaScript before being translated into assembly and placed onto EEPROM external cartridges, to be read by the ATMega128 inside the console. Sound and music are generated using the ATMega’s hardware timers, with a little help from a reverse-biased transistor for white noise and a few op-amps.

From someone who claims to have known little about electronics at the beginning of the project, this is pretty impressive stuff. Our only quibbles are the delay in telling us about it, and the lack of an Asteroids implementation. The former is forgivable, though, because the documentation is so thorough and the project is so cool. The latter? Well, one can hope.

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Kinetic Wire Animatronics Bend It Like Disney

December 26, 2018 by 11 Comments

The House of Mouse has been at the forefront of entertainment technology from its very beginnings in an old orange grove in Anaheim. Disney Imagineers invented the first modern animatronics in the 1960s and they’ve been improving the technology ever since, often to the point of being creepy.

But the complicated guts of an animatronic are sometimes too much for smaller characters, so in the spirit of “cheaper, faster, better”, Disney has developed some interesting techniques for animated characters made from wire. Anyone who has ever played with a [Gumby] or other posable wireframe toys knows that eventually, the wire will break, and even before then will plastically deform so it can’t return to its native state.

Wires used as the skeletons of animated figures can avoid that fate if they are preloaded with special shapes, or “templates,” that redirect the forces of bending. The Disney team came up with a computational model to predict which template shapes could be added to each wire to make it bend to fit the animation needs without deforming. A commercially available CNC wire bender installs the templates that lie in the plane of the wire, while coiled templates are added later with a spring-bending jig.

The results are impressive — the wire skeleton of an animated finger can bend completely back on itself with no deformation, and the legs of an animated ladybug can trace complicated paths and propel the beast with only servos pulling cables on the jointless legs. The video below shows the method and the animated figures; we can imagine that figures animated using this technique will start popping up at Disney properties eventually.

From keeping guests safe from robotic harm to free-flying robotic aerialists, it seems like the Disney Imagineers have a hardware hacker’s paradise at the Happiest Place on Earth.

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Cortex 2 Is One Serious 3D Printed Experimental Rocket

December 25, 2018 by 9 Comments

Rocketry is wild, and [Foaly] is sharing build and design details of the Cortex 2 mini rocket which is entirely 3D printed. Don’t let that fool you into thinking it is in any way a gimmick; the Cortex 2 is a serious piece of engineering with some fascinating development.

Cortex 1 was launched as part of C’Space, an event allowing students to launch experimental rockets. Stuffed with sensors and entirely 3D printed, Cortex 1 flew well, but the parachute failed to deploy mainly due to an imperfectly bonded assembly. The hatch was recovered, but the rocket was lost. Lessons were learned, and Cortex 2 was drafted up before the end of the event.

Some of the changes included tweaking the shape and reducing weight, and the refinements also led to reducing the number of fins from four to three. The fins for Cortex 2 are also reinforced with carbon fiber inserts and are bolted on to the main body.

Here’s an interesting details: apparently keeping the original fins would result in a rocket that was “overstable”. We didn’t really realize that was a thing. The results of overstabilizing are similar to a PID loop where gain is too high, and overcorrection results in oscillations instead of a nice stable trajectory.

Cortex 2 uses a different rocket motor from its predecessor, which led to another interesting design issue. The new motor is similar to hobby solid rocket motors where a small explosive charge at the top of the motor blows some time after the fuel is gone. This charge is meant to eject a parachute, but the Cortex 2 is not designed to use this method, and so the gasses must be vented. [Foaly] was understandably not enthusiastic about venting hot gasses through the mostly-PLA rocket body. Instead, a cylindrical cartridge was designed that both encases the motor and redirects any gasses from the explosive charge out the rear of the rocket. That cartridge was SLA printed out of what looks to us like Formlabs’ High Tempurature Resin.

Finally, to address the reasons Cortex 1 crashed, the hatch and parachute were redesigned for better reliability. A servo takes care of activating the system, and a couple of reverse-polarity magnets assist in ensuring the hatch blows clear. There’s even a small servo that takes care of retracting the launch guide.

The rocket is only half built so far, but looks absolutely fantastic and we can’t wait to see more. It’s clear [Foaly] has a lot of experience and knowledge. After all, [Foaly] did convert a Makerbot printer into a CNC circuitboard engraver.

Fail Of The Week: Hard Lessons In 3D-Printed Bushings For A Giant RC Car

December 25, 2018 by 18 Comments

Can you turn 47 pounds (21 kg) of PLA filament into a gigantic working 3D-printed RC car? No, no you can’t — at least not if you eschew proper bearings in favor of printed bushings.

That’s the hard lesson that [Joel Telling] learned with his scaled up version of the OpenRC F1 car, an RC car that can be mostly 3D-printed. The small version still has its share of non-printed parts, mainly screws and bearings. In his video series documenting the build of the upsized version, [Joel] elaborates on some of the reasons for going with printed bushings rather than bearings, which mainly boil down to hoping that the graphite lubricant powder he added would reduce friction enough to prevent the parts from welding themselves together.

The car came out looking great, and even managed to scoot about nicely for a few seconds before its predictably noisy and unhappy demise. But what was unexpected was the actual failure mode. The plastic-on-plastic running gear seemed to handle the rolling loads fine; it was the lateral force exerted on the axle by the tension of the drive belt that was too much for the printed bushing to bear.

As [Joel] rightly points out, it’s only a failure if you fail to learn something, so kudos to him for at least giving this a try. And all that PLA won’t go to waste, of course — everything else on the car worked fine, so adding one bearing should get it back on the road. He should check out our primer on bearings for a few tips on selecting the right one.

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The Umbrella That Tells You The Weather

December 25, 2018 by 12 Comments

Most people can tell you the various uses of the umbrella — it keeps the rain off, pokes sleeping train passengers awake, and can be used as an improvised defensive weapon when tension in the hot dog line reaches boiling point. A true Englishman would never deign to employ their brolly so imprudently, of course, but they might just give it an upgrade by packing in a full weather station.

Please do not message us to complain about the redundancy of a rain sensor on an umbrella.

The build uses the Particle Photon as the brains of the operation, interfacing it with several sensors. There’s a DHT11 to handle temperature and humidity measurement, an Adafruit barometric pressure sensor, along with a custom-built anemometer using a brushed motor with 3D printed wind cups. Finally, a breadboard is turned into a rain detector, based on the same principles as those used in automotive applications.

 

The Particle Photon uses WiFi to tether to a smartphone, deliver the collected data to the cloud via Adafruit IO. This enables the data to be collated and processed further on a PC. Yes, it’s 2018, and they have the internet on umbrellas now.

As we reach further into the depths of winter, it’s one project that could very much come in handy, and [The Gentlemen Maker] has been kind enough to share the code on Particle.io. If that’s not good enough, perhaps you could use your umbrella as a WiFi antenna. Video after the break.

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Achieving Zen The Arduino Way

December 25, 2018 by 17 Comments

The purpose of a Zen garden, those stylized landscapes created by painstakingly placing rocks and raking gravel into perfect patterns, is the doing of the thing. Making sure every line is perfectly formed is no mean feat, and the concentration required to master it is the point of the whole thing. But who has time for that? Why not just build a robot to create the perfect Zen garden in miniature?

That was what [Tim Callinan] and his classmates did for a semester project, and the “ZenXY” sand plotter was the result. There isn’t a build log for the device per se, although the video below makes it plain how they went about this. The sand table itself is a plywood box whose bottom is layered with fine white sand and contains a single steel ball. Below the table is an X-Y gantry carrying a powerful magnet. A gShield riding on top of an Uno turns G code into slow, stately movement of the ball through the sand. The patterns are remarkably intricate, and while it might not be the same as mastering the body control needed to rake gravel with precision, watching the ball push the sand around is pretty Zen all by itself

This isn’t the first time we’ve seen someone try to automate a traditional Japanese practice. This tea ceremony robot comes to mind, and this nicely crafted sand table is very similar to the ZenXY.

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How A Microcontroller Hiding In A USB Port Became An FPGA Hiding In The Same

December 25, 2018 by 21 Comments

When you think of microcontroller development, you probably picture either a breadboard with a chip or a USB-connected circuit board. But Tim Ansell pictured an ARM dev board that is almost completely hidden inside of a USB port. His talk at the 2018 Hackaday Superconference tells that story and then some. Check out the newly published video, along with more details of the talk, after the break.

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