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LEGO Orrery Gets A Real-Time Drive Upgrade

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An orrery is a beautiful type of mechanical contrivance, built to demonstrate the motion of heavenly objects. LEGO happens to offer just such a device, built using its Technic line of blocks, shafts, and gears. Only, it has a serious limitation—it has to be cranked manually to make it spin the Earth around the sun. [Görkem] set out to fix this glaring oversight with some good old-fashioned hardware. The setup removes just five LEGO pieces from the original design, eliminating the hand crank from the mechanism. In its place, [Görkem] installed a NEMA 17 stepper motor, paired with a custom PCB mounted on the back. That carries an ESP32 microcontroller and a TMC2208 stepper motor driver set up for silent drive. Rigged up like so, the orrery can simulate the motion of the Earth and Moon around the Sun in real time. There’s also a knob to track back and forth in time, and a button to reset the system to the correct real-time position. The final build looks great, combining the LEGO Techn...
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A Basic Guide To Shielding

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[GreatScott] has recently been tinkering in the world of radio frequency emissions, going so far as to put their own designs in a proper test chamber to determine whether they meet contemporary standards for noise output. This led them to explore the concept of shielding, and how a bit of well-placed metal can make all the difference in this regard. The video focuses on three common types of shielding—absorber sheets, shielding tapes, and shielding cabinets. A wide variety of electronic devices use one or more of these types of shielding. [GreatScott] shows off their basic effectiveness by putting various types of shielding in between a noise source and a near-field probe hooked up to a receiver. Just placing a bit of conductive material in between the two can cut down on noise significantly. Then, a software defined radio (SDR) was busted out for some more serious analysis. [GreatScott] shows how Faraday cages (or simple shielding cabinets] can be used to crush down spurious RF outp...
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A Computer That Fits Inside A Camera Lens

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For a long while, digital single-lens reflex (DSLR) cameras were the king of the castle for professional and amateur photography. They brought large sensors, interchangeable lenses, and professional-level viewfinders to the digital world at approachable prices, and then cemented their lead when they started being used to create video as well. They’re experiencing a bit of a decline now, though, as mirrorless cameras start to dominate, and with that comes some unique opportunities. To attach a lens meant for a DSLR to a mirrorless camera, an adapter housing must be used, and [Ancient] found a way to squeeze a computer and a programmable aperture into this tiny space . The programmable aperture is based on an LCD screen from an old cell phone. LCD screens are generally transparent until their pixels are switched, and in most uses as displays a backer is put in place so someone can make out what is on the screen. [Ancient] is removing this backer, though, allowing the LCD to be complete...
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Retrotechtacular: Mr. Wizard Jams with IBM

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You may not remember [Mr. Wizard], but he was a staple of nerd kids over a few decades, teaching science to kids via the magic of television. The Computer History Archives Project has a partially restored film of [Mr. Wizard] showing off sounds and noise on a state-of-the-art (for 1963) Tektronix 504 oscilloscope. He talks about noise and also shows the famous IBM mainframe rendition of the song “Daisy Bell.” You can see the video along with some extras below. You might recall that the movie “2001: A Space Odyssey” paid homage to the IBM computer’s singing debut by having HAL 9000 sing the same song as it is being deactivated. The idea that HAL was IBM “minus one” has been repeatedly denied, but we still remain convinced. Can you imagine a TV show these days that would teach kids about signal-to-noise ratio or even show them an actual oscilloscope? We suppose that’s what YouTube is for. At about the 17-minute mark, you can see some enormous walkie-talkies. A far cry from today’s ...
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Keebin’ with Kristina: the One With the NEO With the Typewriter Shell

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Isn’t this glorious? If you don’t recognize what this is right away (or from the post title), it’s an AlphaSmart NEO word processor , repackaged in a 3D-printed typewriter-esque shell, meticulously designed by the renowned [Un Kyu Lee] of Micro Journal fame. Image by [Un Kyu Lee] via GitHub If you don’t want to spend roughly 40 hours printing ~1 kg of filament in order to make your own, you can join the wait-list on Tindie like I did. Go here to figure out which color you want, and email [Un Kyu Lee] when you order. In the meantime, you can watch the assembly video and then check out this playlist that shows the available colors . Assembly looks easy enough; there’s no soldering, but you do have to disconnect and reconnect the fiddly ribbon cables. After that, it’s just screws. This design happened by accident. A friend named [Hook] who happens to manage the AlphaSmart Flickr community had given [Un Kyu Lee] a NEO2 to try out, but before he could, it fell from a shelf and the...
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Microfluidic Display Teaches The Basics

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We’ve always been interested in fluidic logic and, based on [soiboi’s] videos, he is too. His latest shows how to use silicone and a vacuum to build a multiplexed dot matrix display . This is a fascinating look at how you design with air instead of electrons. Just like a regular display, it isn’t efficient to control each element separately. Usually, it’s better to multiplex such that 16 “pixels” need only row and column air valves. Just as you might use transistors, the project uses “air transistors” to build logic gates. Each pixel is a bit of silicone that can be sucked down only when a row and column are drawing a vacuum simultaneously. The air transistor is a similar membrane that a control input can suck down. In its relaxed position, two air channels are blocked by the membrane. When the membrane moves away, the two channels connect. This is analogous to a Field Effect Transistor (FET), where the channel conducts electricity when the gate is active and does not conduct when ...
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Removing the BIOS Administrator Password on a ThinkPad Takes Timing

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This would be a bad time to slip. (Credit: onionboots, YouTube) In the olden days, an administrator password on a BIOS was a mere annoyance, one quickly remedied by powering off the system and pulling its CMOS battery or moving a jumper around. These days, you’re more likely to find a separate EEPROM on the mainboard that preserves the password. This, too, is mostly just another annoyance, as [onionboots] knew. All it takes is shorting out this EEPROM at the right time to knock it offline, with the ‘right time’ turning out to be rather crucial. While refurbishing this laptop for a customer, he thought it’d be easy: the guide he found said he just had to disassemble the laptop to gain access to this chip, then short out its reset pin at the right time to make it drop offline and keep it shorted. Important here is that you do not short it when you are still booting the system, or it won’t boot. This makes for some interesting prodding of tiny pins with a metal tool. What baffled ...
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