Augmented Reality Pinball

Pinball machines are fascinating pieces of mechanical and electrical engineering, and now [Yair Moshe] and his students at the Israel Institute of Technology has taken the classic game one step further.  Using computer vision and a projector, this group of engineers has created an augmented reality pinball game that takes pinball to a whole new level.

Once the laptop, webcam, and projector are set up, a course is drawn on a whiteboard which the computer “sees” to determine the rules of the game. Any course you can imagine can be drawn on the whiteboard too, with an interesting set of rules that no regular pinball game could take advantage of. Most notably, the ball can change size when it hits certain types of objects, which makes for a very interesting and unconventional style of play.

The player uses their hands to control the flippers as well, but not with buttons. The computer watches the position of the player’s hands and flips the flippers when it sees a hand in the right position. [Yair] and his students recently showed this project off at DLD Tel Aviv and even got [Shimon Perez], former President of Israel, to play some pinball at the conference!

Chicken-powered Pendulum

Every once in a while we get sent a link that’s so cute that we just have to post it. For instance: this video from [Ludic Science]. It’s a wind-up chicken toy that kicks a pendulum back and forth. No more, no less.

But before you start screaming “NOT A HACK!” in the comments below, think for a second about what’s going on here. The bird has a spring inside, and a toothed wheel that is jammed and released by the movement of the bird’s foot (an escapement mechanism). This makes the whole apparatus very similar to a real pendulum clock.

Heck, the chick toy itself is pretty cool. It’s nose-heavy, so that under normal conditions it would tip forward. But when it’s wound up, tipping forward triggers the escapement and makes it hop, tipping it backward in the process and resetting the trigger. The top-heavy chicken is an inverted pendulum!

And have a look, if you will indulge, at the very nice low-tech way he creates the pivot: a bent piece of wire, run through a short aluminum tube, held in place by a couple of beads. Surely other pivots are lower-friction, but the advantage of using a rod and sleeve like this is that the pendulum motion is constrained to a plane so that it never misses the chicken’s feet.

Our only regret is that he misses (by that much) the obvious reference to a “naked chick” at the end of the video.

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A 4-bit Computer From Discrete Transistors

Anyone reading this uses computers, and a few very cool people have built their own computer out of chips, [zaphod] is doing something even cooler over on he’s building a computer from discrete transistors.

Building a computer from individual components without chips isn’t something new – Minecraft players who aren’t into cheaty command blocks do it all the time, and there have been a few real-life builds that have rocked our socks. [zaphod] is following in this hallowed tradition by building a four-bit computer, complete with CPU, RAM, and ROM from transistors, diodes, resistors, wire, and a lot of solder.

The ROM for the computer is just a bunch of 16 DIP switches and 128 diodes, giving this computer 128 bits of storage. the RAM for this project is a bit of a hack – it’s an Arduino, but that’s only because [zaphod] doesn’t want to solder 640 transistors just yet. This setup does have its advantages, though: the entire contents of memory can be dumped to a computer through a serial monitor. The ALU is a 4-bit ripple-carry adder/subtractor, with plans for a comparison unit that will be responsible for JMP.

The project hasn’t been without its problems – the first design of the demux for the ROM access logic resulted in a jungle of wires, gates, and connections that [zaphod] couldn’t get a usable signal out of because of the limited gate fan-out of his gates. After looking at the problem, [zaphod] decided to look at how real demuxes were constructed, and eventually hit upon the correct way of doing things – inverters and ANDs.

It’s a beautiful project, and something that [zaphod] has been working for months on. He’s getting close to complete, if you don’t count soldering up the RAM, and already has a crude Larson scanner worked out.

Open-Source Laser Shooting Simulator

Looking to practice your marksmanship skills at home? Check out the homeLESS (Home LasEr Shooting Simulator), an open-source tool for marksmanship practice. [Laabicz] developed this system as a cheaper alternative to commercial laser shooting simulators, which are just as simple but very expensive.

[Laabicz]’s simulator primarily uses modified airsoft pistols that are fitted with batteries (installed in the magazine) and a laser in the chamber. Any gun can be used with the system as long as you can figure out how to attach a laser and trigger switch. To power the laser, a small capacitor is charged from batteries when the trigger switch is off. Once the trigger is pressed, the capacitor discharges through the laser and makes a short pulse of light.

The simulator is written in Processing and requires a projector and a webcam. The Processing sketch projects configurable moving targets on a screen or wall, and the webcam detects when a laser is triggered over any of the targets. The software supports multiple target types (including moving targets) and is quite configurable. Check out the video after the break to see the system in use.

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Video Spiel Kultur

Somehow, and don’t ask us how, the venue we chose for the Hackaday Prize party was perfect for Hackaday-related shenanigans. There was a Hackerspace right around the corner, a computer history museum in a warehouse nearby, and an amazing video game archive barely 100 meters away from our venue.

The VideoGamingArchive is an amazing collection of video games from the era where video games came in boxes with real manuals, and you needed to be sure you bought the game compatible with your system. Inside, one wall is dedicated to the old cardboard computer boxes, indexed partly by system and partly by how cool they look, while the other wall was dedicated to games from the previous five generations of consoles.

[Nils] was kind enough to give me a tour. You can check that video out below, with some more pics below that. If you’re wondering, yes, that is a sealed copy of Chrono Trigger, and no, I have no idea what it’s worth.

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Interactive Sound with Glove and Tape

Here’s a way to explore new spaces in untraditional manners: a sonophore, or a glove equipped with a tape heads meant to explore spaces with magnetic tape tracing the walls.

This project is a followup to the analogue tape glove from a few years ago. In that project, aligned strips of magnetic tape cover a canvas, leaving anyone wearing the glove to track their hand horizontally swiping across different tracts, or vertically listening to each track.

This project takes a glove similar to the analogue tape glove, but the tape is spread out along the walls of the installation. There’s no way of knowing what strange voices are contained on the tapes; the only way to know is to explore the space.

Video of the project below. It’s a Vimeo, so you know it’s artistic.

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Atari Video Game Burial Hits Ebay

1983 was the year of the great video game crash, and after the chiefs of Atari realized they had produced more copies of Pac-Man than consoles sold, these games, along with other ‘treasures’ were loaded into trucks, shipped out to the desert, and buried in a New Mexico landfill. Last year, these consoles were rescued. Now, thanks to the efforts of the Tularosa Basin Historical Society, these cartridges are for sale again.

Want to grab your own copy of E.T., Asteroids, Star Raiders, or Centipede rescued from a landfill in a desert? Here’s a link to the seller on eBay, with the highest auction being E.T., in box, going for $400 with nine days left. The auction comes with a certificate of authenticity from the city of Alamogordo.

This is only the first batch of cartridges and boxes rescued from the dump, with the Tularosa Basin Historical Society putting at least another 700 items up for sale if this batch goes well.

With the rousing success of this bit of dumpster diving, we must point out another techno-archeological myth/legend: there are several thousand Apple Lisas in a Utah landfill, just waiting for someone to come in and pick through the remnants of an Apple tax writeoff.