Beer Pong Difficulty Level: 10

November 21, 2020 by Bryan Cockfield 2 Comments

Beer pong is a fun enough game for those of a certain age, but one thing that it lacks is a way of cranking up the difficulty setting independent of the amount of beer one has consumed. At least, that was the idea [Ty] had when he came up with this automated beer pong table which allows the players to increase the challenge of this game by sliding the cups around the top of the table.

The build uses a belt-driven platform under a clear cover with a set of magnets attached. Each of the cups on the table has a corresponding magnet, which allows them to slide fairly easily back and forth on the table. The contraption is controlled by an Arudino Nano with a small screen and dial that allows the players to select a difficulty level from 1 to 10. The difficulty levels increase the speed that the cups oscillate on the table, which certainly adds another layer of complexity to this already challenging game.

While we hope to eventually see a beer pong table that can automatically arrange the cups as the game is played, we do appreciate the effort to make an already difficult game even more difficult. Of course, if you have problems with the difficulty level you might want to pick up a PongMate CyberCannon Mark III to help with those clutch beer pong shots.

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A Computer In The Game Of Life

November 21, 2020 by Matthew Carlson 20 Comments

We often hear the term “Turing-complete” without giving much thought as to what the implications might be. Technically Microsoft PowerPoint, Portal 2, and Magic: the Gathering all are Turing-complete, what of it? Yet, each time someone embarks on an incredible quest of perseverance and creates a computer in one of these mediums, we stand back in awe.

[Nicolas Loizeau] is one such individual who has created a computer in Conway’s Game of Life. Unlike electricity, the Game of Life uses gliders as signals. Because two orthogonal gliders can cancel each other out or form a glider eater if they intersect with a good phase shift, the basic logic gates can be formed from these interactions. This means the space between gates is crucial as signals need to be in phase alignment. The basic building blocks are a period-60 gun, a 90-degree glider reflector, a glider duplicator, and a glider eater.

All the Python code that generates these structures is on GitHub as the sheer size of the machine couldn’t possibly be placed by hand. The Python includes scripts to assemble the basic programs as a bank of selectable glider generators. It’s all based on Golly, which is an excellent program for simulating Conway’s Game of Life, among other things. While this isn’t the first computer in the Game of Life as [Paul Rendell] published a design in 2000 and [Adam Goucher] published a Spartan universal computer constructor in 2009, we think this is a particularly beautiful one.

The actual architecture has an 8-bit data bus, a 64-byte memory with two read ports, a ROM with 21 bits per line, and a one-hot encoded ALU supporting 8 different operations. Instructions have a 4-bit opcode which is decoding in a few different instructions. The clock is four loops, formed by the glider reflectors as the glider beams rotate. This gives the computer four stages: execution, writing, increment PC, and write PC to memory.

The Game of Life is an excellent example of Cellular Automaton (CA). There are several other types of CA’s and the history behind them is fascinating. We’ve covered this field before and delved into this beautiful fringe of computer science. Check out the video below to truly get a sense of the scale of the machine that [Nicolas] has devised.

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A Rocket Powered Ejection Seat For Model Aircraft

November 21, 2020 by Lewin Day 4 Comments

As radio control planes don’t typically have human pilots onboard, the idea of installing an ejection seat in one is somewhat frivolous. But that doesn’t mean it wouldn’t be a lot of fun, and [James Whomsley] has set his mind to achieving the task.

The build process is an iterative one, with [James] solving problems step-by-step and testing along the way. The first task was to successfully launch a small action figure and his flight seat vertically in a controlled fashion. After a few attempts, a combination of rocket motors and guide rails were settled upon that could achieve the goal. Next up, a drogue parachute system was designed and tested to stabilize the seat at the height of its trajectory. Further work to come involves handling seat separation and getting the action figure safely back to the ground.

While action figures aren’t alive and the ejection seat serves no real emergency purpose, we can imagine it would be a hit at the local flying field – assuming the parachutes don’t get tangled in someone else’s model. For those interested in the real technology, our own [Dan Maloney] did a great piece on the topic. Video after the break.

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Among Us Emergency Meeting Button Becomes Reality

November 21, 2020 by Lewin Day 3 Comments

Among Us has been an indie gaming success story. A game built by a small team has, after several years on the market, become a worldwide sensation. Gameplay consists of players attempting to find the imposter amongst their ranks and an “Emergency Meeting” can be called if players need to speak to each other. [john lemme] wanted to be able to do the same with his roommates, and set about building the real thing.

The build relies on an ESP32, which reads the state of a big red emergency button. When pressed, the ESP32 uses its WiFi connection to trigger a Discord conference call containing all the roommates. Naturally, it also plays the buzzer sound from the actual game, too – via a small amplifier and a speaker yanked from some headphones.

It’s a fun build, though [john] notes it has its limits. The call takes 10 seconds to initiate after the button press, and the audio hardware doesn’t do a great job of recreating the buzzer noise from the game. However, it’s a good starting point, and we think the concept could actually prove useful with some refinement. Video after the break.

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High-Speed Spectrometer Built With Cheap Linear CCD

November 21, 2020 by Tom Nardi 35 Comments

If you’ve ever dreamed of building a proper spectrometer, it looks like the ESPROS epc901 CCD sensor is absolutely worth your attention. It’s fast, sensitive, easy to interface with, and at just $24 USD, it won’t break the bank. There’s only one problem: implementing it in your project means either working with the bare 2×16 0.5 mm pitch BGA device, or shelling out nearly $1,400 USD for the development kit.

Thankfully, [Adrian Studer] has come up with a compromise. While you’ll still need to reflow the BGA to get it mounted, his open hardware breakout and adapter boards for the ESPROS epc901 make the sensor far easier to work with.

It’s not just a hardware solution either, he also provides firmware code for the STM32L4 based Nucleo development board and some Python scripts that make it easy to pull data from the sensor. The firmware even includes a simple command line interface to control the hardware that you can access over serial.

With the sensor successfully wrangled, [Adrian] partnered with [Frank Milburn] to build an affordable spectrometer around it. The design makes use of a 3D printed chamber, a simple commercial diffraction grating, and an array of entrance slits ranging from 0.5 to 0.0254 millimeters in width that were laser-cut into a sheet of stainless steel.

In the videos after the break, you can see the finished spectrometer being used to determine the wavelength of LEDs, as well as a demonstration of how the high-speed camera module is able to study the spectral variations of a CFL bulb over time. [Adrian] tells us that he and [Frank] are open to suggestions as to what they should point their new spectrometer at next, so let them know in the comments if you’ve got any interesting ideas.

We’ve seen an incredible number of spectrometer builds over the years, and some of the more recent ones are really pushing the envelope in terms of what the DIY scientist is capable of doing in the home lab. While they’re still fairly niche, these instruments are slowly but surely finding their way into the hands of more curious hackers.

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Why You Need To Finish

November 21, 2020 by Elliot Williams 31 Comments

Mike and I were talking about an interesting smart-glasses hack on the podcast. This was one of those projects where, even if you don’t need a pair of glasses with LEDs on them to help you navigate around, you just couldn’t help but marvel at a lot of the little design choices made throughout.

For instance, I love the way the flex PCB is made to do double duty by wrapping around the battery and forming a battery holder. This struck me as one of those quintessential hacks that only occurs to you because you need it. Necessity is the mother of invention, and all that. There was a problem, how to fit a battery holder in the tiny space, and a set of resources that included a flex PCB substrate. Cleverly mashing that all together ended up with a novel solution. This wouldn’t occur to you if you were just sitting at the beach; you’d have to be designing something electronic, space-constrained, and on a flex PCB to come up with this.

Mike made an offhand comment about how sometimes you just need to finish a project for the good ideas and clever solutions that you’ll come up with along the way, and I think this battery holder example drives that point home. I can’t count the number of my projects that may or may not have been dumb in retrospect, but along the way I came up with a little trick that I’ll end up using in many further projects, outliving the original application.

Finishing up a project on principle is a reasonable goal just on its own. But when the process of seeing something to conclusion is the generator of new and interesting challenges and solutions, it’s even more valuable. So if you’re stuck on a project, and not sure you want to take it all the way, consider if the journey itself could be the destination, and look at it as an opportunity to come up with that next long-lasting trick.

Bad News: Arecibo

If you read the newsletter last week, you heard me wondering aloud if the damage to Arecibo Observatory had crossed the threshold into where it’s no longer economically viable to keep it running, and the sad news has just come in and the battle for Arecibo has been lost. We said we’d shed a tear, and here we are. Sic transit gloria mundi. Here’s hoping something cooler replaces it!

Reduce, Reuse, Injection Mold

November 21, 2020 by Al Williams 34 Comments

Many people have the means now to create little plastic objects thanks to 3D printing. However, injection molding is far less common. Another uncommon tech is plastic recycling, although we do occasionally see people converting waste plastic into filament. [Manuel] wants to solve both of those problems and created an injection molder specifically for recycling.

The machine — Smart Injector — is automated thanks to an Arduino. It’s pretty complex mechanically, so in addition to CAD models there are several PDF guides and a ton of pictures showing how it all goes together.

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