Why Pendulums Sync Up, And Other Mysteries Explained

April 12, 2021 by Zoe Skyforest 6 Comments

If you’ve ever seen fireflies flashing together at night, you’ve witnessed the glory of synchronisation. In a new video, [Veritasium] examines some of the mechanisms in nature that help create order out of chaos.

The story begins back in 1665, when [Christiaan Huygens] discovered that two pendulum clocks hanging from the same wooden beam would spontaneously synchronise over a period of time. The same principle is then demonstrated with metronomes – an experiment readily recreated in the home. Other systems that show this same eerie coordiation are then explored – from tidally locked moons orbiting around planets (like ours!), to chemical oscillators discovered by Soviet scientists during the cold war. There’s also a great explanation of the problems faced by the London Millennium Bridge, which swayed wildly under heavy foot traffic as it induced pedestrians to walk in sync.

Overall, it’s a look at some of the action behind the scenes that ties seemingly independent systems together. Learning about such things can prove useful too – it might even help you solve real world problems in your machine shop! Video after the break.

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Code Your Own Twitch Chat Controls For Robots — Or Just About Anything Else!

April 8, 2021 by Zoe Skyforest 3 Comments

Twitch Plays Pokemon burst onto the then nascent livestreaming scene back in 2014, letting Twitch viewers take command of a Game Boy emulator running Pokemon Red via simple chat commands. Since then, the same concept has been applied to everything under the sun. Other video games, installing Linux, and even trading on the New York Stock Exchange have all been gameified through Twitch chat.

*TwitchPlaysPokemon* started a craze in crowdsourced control of video games, robots, and just about everything else.

You, thirsty reader, are wondering how you can get a slice of this delicious action. Fear not, for with a bit of ramshackle code, you can let Twitch chat take over pretty much anything in, on, or around your computer.

It’s Just IRC

The great thing about Twitch chat is that it runs on vanilla IRC (Internet Relay Chat). The protocol has been around forever, and libraries exist to make interfacing easy. Just like the original streamer behind Twitch Plays Pokemon, we’re going to use Python because it’s great for fun little experiments like these. With that said, any language will do fine — just apply the same techniques in the relevant syntax.

SimpleTwitchCommander, as I’ve named it on Github, assumes some familiarity with basic Python programming. The code will allow you to take commands from chat in two ways. Commands from chat can be tabulated, and only the one with the most votes executed, or every single command can be acted on directly. Actually getting this code to control your robot, video game, or pet viper is up to you. What we’re doing here is interfacing with Twitch chat and pulling out commands so you can make it do whatever you like. With that said, for this example, we’ve set up the code to parse commands for a simple wheeled robot. Let’s dive in.

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Mercedes Split Turbo Was A Game Changer In Formula 1

April 6, 2021 by Zoe Skyforest 40 Comments

In 2014, Formula 1 switched away from V8 engines, electing instead to mandate all teams race with turbocharged V6 engines of 1.6 litres displacement, fitted with advanced energy recovery systems. The aim was to return Formula 1 to having some vague notion of relevance to modern road car technologies, with a strong focus on efficiency. This was achieved by mandating maximum fuel consumption for races, as well as placing a heavy emphasis on hybrid technology.

The Mercedes W05 Hybrid was the first of 7 championship-winning F1 cars from the British-based, German-funded team. It quickly showed the value of the team’s split-turbo technology.

Since then, Mercedes have dominated the field in what is now known as the turbo-hybrid era. The German team has taken home every drivers and constructors championship since, often taking home the crown well before the season is over. Much has been made of the team’s engine as a key part of this dominance, widely considered to be more powerful and efficient than the competition at all but a few select races in the last seven years, and much of the credit goes to the company’s innovative split-turbo system. Today, we’ll explore why the innovation was such a game changer in Formula 1.

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Arduino Plots Your Portrait With Style

April 5, 2021 by Zoe Skyforest 2 Comments

Around these parts, we see plenty of plotter builds. They’re a great way to learn about CNC machines and you get to have fun making pictures along the way. [Ben Lucy] was undertaking just such a build of his own, but wanted to do something standalone that served a purpose. The result is the impressive Portable Portrait Painter.

What sets [Ben]’s project apart is how complete it is. Unlike other plotters that simply follow G-code instructions or process external images, the Portable Portrait Painter is a completely standalone machine. Fitted out with an OV7670 camera, hooked up to an Arduino, it’s capable of taking its own photos and then drawing them out as well.

Through some clever code from [Indrek Luuk], the Arduino Mega2560 is able to display a 20fps video preview on a color LCD screen. When the user presses a button, the current frame is captured and sent to the pen plotter. The plotting algorithm is particularly impressive, with images first processed with histogram compensation to maximise contrast. The pen is then drawn across the page line by line, and pressed into the page by varying amounts depending on the color value of each pixel. The darker the pixel, the thicker the stroke made by the pen. This more analog approach produces a much more detailed image than more basic plotters which either leave a mark or don’t.

The portraits produced by the plotter are impressive, and we like the edge-of-page artifacts, which add a little style to the final results. The Portrait Painter would make a great conversation piece at any Maker Faire or hackerspace night.

It’s a project that reminds us of some of the painting robots we’ve seen over the years. Video after the break.

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Decoding S/PDIF With A Microcontroller Brings A Few Headaches

April 4, 2021 by Zoe Skyforest 14 Comments

The average punter shunts audio around with analog 3.5 mm cables, RCA jacks, or Bluetooth on a regular basis. A useful standard that hasn’t really bothered most of us is S/PDIF, standing for Sony/Phillips Digital Interface. It’s a useful way to pump digital audio around over copper cables or optic fiber. [Andrew Jeddeloh] got curious about the standard after contemplating some long cable runs in his home, and decided to try decoding it.

The target for [Andrew]’s development efforts was the STM32L476 Discovery, which had no SPDIF decoding hardware on board. Instead, [Andrew] tinkered with the peripherals he had to see what would work. In the end, a cavalcade of internal timers were daisy chained to allow the microcontroller to recover a clock from the self-clocked S/PDIF signal. This was then used to generate a clock to sync up the onboard SPI hardware to actually read in the 16-bit PCM data from the S/PDIF signal.

[Andrew]’s original broader plan was to pipe the S/PDIF data to the onboard I2S DAC, though he struggled manipulating the remaining resources on the STM chip to do so successfully. Anyone wishing to have a crack can take a look at [Andrew]’s code over on GitHub. If completed, the STM32L476 would become a useful analog endpoint for S/PDIF streams, allowing you to pump tunes digitally over long distances without signal degradation. If you know the key to getting it done, sound off in the comments! Alternatively, if you need to get up and running more quickly, the Teensy platform has you covered!

You Can Now Build Your Own Glowing LED D20 (with A Whopping 2,400 LEDs)

April 3, 2021 by Zoe Skyforest 9 Comments

The D20, or twenty-sided die, is most commonly known in the shape of a regular icosahedron. It’s a fantastic, enchanting geometry, and one that has held the balance of fate in innumerable tabletop roleplaying games over the years. It was this sacred geometry that [Greg Davill] chose to bless with the glory of glowing RGB LEDs. Now, [Greg] has shared the files so you can build your own.

The development blog of the D20 is a great read, highlighting the challenges of creating such a compact item that glows so brilliantly. The design uses a full 2400 1.5 mm x 1.5mm LEDs, in the old-school RGB style, split evenly between the twenty sides. That’s right, there’s no fancy self-addressing smart LEDs here — each LED is manually controlled directly by [Greg]’s hardware. A SAMD51 and ICE40UP5K FPGA are put to work running the displays. Each panel is held together in a barely-there 3D printed frame, linked together with ribbon cables to keep things compact. A Sony camera battery is slotted inside the tight confines of the frame to supply the necessary power.

We first covered the project late last year, and it’s great to see it out there now in a form that’s readily reproduced. Assembly of such a board is not for the faint of heart, however, with plenty of fine SMD parts to tangle with. We suspect this is just yet another salvo in the ongoing arms race of LED glowables, and we can’t wait to see what [Greg] — and the rest of the community — comes out with next. If you’ve got a lead on the new glowing hotness, let us know. Video after the break.

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Finger Bend Is A Textile Flex Sensor You Can Sew At Home

April 2, 2021 by Zoe Skyforest 2 Comments

So often, we use control devices for electronics that involve our fingers directly grasping, touching, or moving another object or surface. It’s less common for us to use interfaces that detect the motion of our bodies directly. Flex sensors are one way to do that, and it’s exactly what [WillpowerStudios] aims to do with Finger Bend.

The construction of the sensor is simple, using piezoresistive fabric which changes its resistance when deformed. By sewing this into a sheath that can be placed on the finger, and wiring it up with conductive threads, it can be used to detect the flexion of the wearer’s digits by sampling the resistance with an analog to digital converter on any garden variety microcontroller. Expanding the technique to a full hand is as simple as creating a Finger Bend per digit and wiring up each one to its own ADC channel. If you want to get really fancy, you could even scan through them at speed with a multiplexer.

It’s similar to the technology used in Nintendo’s infamous Power Glove, and while it’s never caught on in the mainstream, it may have applications yet. Video after the break

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