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For many people, the biggest change of 2020 has been adjusting to a glut of online teleconferences as a part of daily working life. [p_leriche] has had to adjust the way church services are conducted, and found managing a complicated streaming meeting setup to be complicated at best. To ease the workload on the presenter, he created a simple Zoom control box. At its heart, the box is little more than a fancy keyboard. An Arduino Pro Micro is hooked up to a series of brightly colored pushbuttons, each labelled with regularly used Zoom functions. The Pro Micro is programmed to fire off the corresponding keyboard shortcuts when the buttons are pressed, activating the relevant function. It might be a simple build, but it greatly reduces the hand gymnastics required mid-presentation, and we’re sure the users greatly appreciate the new hardware. While this is a quick-and-dirty build thrown together in a basic enclosure, macro keyboards can be both useful and attractive if you so desire. I

Git’s Large File System is a reasonable solution to a bit of a niche problem. How do you handle large binary files that need to go into a git repository? It might be pictures or video that is part of a project’s documentation, or even a demonstration dataset. Git-lfs’s solution is to replace the binary files with a taxt-based pointer to where the real file is hosted. That’s not important to understanding this vulnerability , though. The problem is that git-lfs will call the main git binary as part of its operation, and when it does so, the full path is not used. On a Unix system, that’s not a problem. The $PATH variable is used to determine where to look for binaries. When git is run, /usr/bin/git is automagically run. On a Windows system, however, executing a binary name without a path will first look in the current directory, and if a matching executable file is not found, only then will the standard locations be checked. You may already see the problem. If a repository contains

The Raspberry Pi Compute Module 4 has got many excited, with a raft of new features bringing exciting possibilities. However, for those used to the standard Raspberry Pi line, switching over to the Compute Module form factor can be daunting. To show just how easy it is to get started, [timonsku] set about producing a quick and dirty carrier board for the module at home . The Twitter thread goes into further detail on the design of the board. The carrier features HDMI, USB-A and USB-C ports, as well as a microSD slot. It’s all put together on a single-sided copper PCB that [timonsku] routed at home. The board was built as an exercise to show that high-speed signals and many-pin connectors can be dealt with by the home gamer, with [timonsku] sharing tips on how to get the job done with cheap, accessible tools. The board may look rough around the edges, but that’s the point. [timonsku] doesn’t recommend producing PCBs at home when multi-layer designs can be had cheaply from overseas. I

Calculating three-dimensional position from two-dimensional projections are literal textbook examples in geometry, but those examples are the “assume a spherical cow” type of simplifications. Applicable only in an ideal world where the projections are made with mathematically perfect cameras at precisely known locations with infinite resolution. Making things work in the real world is a lot harder. But not only have [Jingtong Li, Jesse Murray et al.] worked through the math of tracking a drone’s 3D flight from 2D video, they’ve released their MultiViewUnsynch software on GitHub so we can all play with it. Instead of laboratory grade optical instruments, the cameras used in these experiments are available at our local consumer electronics store. A table in their paper Reconstruction of 3D Flight Trajectories from Ad-Hoc Camera Networks (arXiv:2003.04784) listed several Huawei cell phone cameras, a few Sony digital cameras, and a GoPro 3. Video cameras don’t need to be placed in any p

It seems there are as many ways to display the time as there are ways to measure it in the first place. [Kothe] saw a fancy designer domino clock, and wanted a piece of the action without the high price tag. Thus, the natural solution was to go the DIY route. An Arduino Nano is the heart of the build, paired with a DS1307 RTC for accurate timekeeping. The case of the clock consists of a 3D printed housing, fitted with layers of lasercut acrylic. Behind this, a smattering of WS2812B addressable LEDs are fitted, which shine through the translucent grey plastic of the front panel. This enables each LED to light up a dot of the domino, while remaining hidden when switched off. Reading the time is as simple as counting the dots on the dominoes. The first domino represents hours, from 1 to 12, while the second and third dominoes represent the minutes. As a timepiece, the domino clock serves well as a stylish decor piece, and could also be a fun way to teach kids about electronics and telli

If you made a motor out of a magnet, a wire coil, and some needles, you probably remember that motors and generators depend on a rotating magnetic field. Once you know how it works, the concept is pretty simple, but did you ever wonder who worked it all out to start with? Tesla figures into it, unsurprisingly. But what about Michael Dobrowolsky or Walter Bailey? Not common names to most people. [Learn Engineering] has a slick video covering the history and theory of rotating magnetic field machines , and you can watch it below. Motors operated on direct current were not very practical at the time and caused a jerky motion. However, Tesla and another inventor named Ferraris realized that AC current could cause a rotating magnetic field without a moving commutator. Tesla’s motor used two AC currents with a 90-degree phase difference produced by his two-phase generator. Ferraris used a single phase along with an inductor to create the phase difference. However, two-phase motors have li

We know that the Hackaday family includes many enthusiasts for quality keyboards, and thus mention of the fabled ‘boards of yore such as the IBM Model F is sure to set a few pulses racing. Few of us are as lucky as [Brennon], who received the familial IBM PC-XT complete with its sought-after keyboard . This Model F has a manufacture date in March 1983, and as a testament to its sturdy design was still in one piece with working electronics. It was however in an extremely grimy condition that necessitated a teardown and deep clean. Thus we are lucky enough to get a peek inside, and see just how much heavy engineering went into the construction of an IBM keyboard before the days of the feather-light membrane devices that so many of us use today. There follows a tale of deep cleaning, with a Dremel and brush, and then a liberal application of Goo Gone. The keycaps had a long bath in soapy water to remove the grime, and we’re advised to more thoroughly dry them should we ever try this as s

Traditional military-grade nightvision gear has a history stretching back to the Second World War, relying on photomultiplier tubes to help soldiers see in the dark. Such devices have trickled down to the civilian market in intervening years, however other simpler techniques can work too. [Happy_Mad_Scientist] whipped up a simple nightvision monocular using a very sensitive camera instead. Due to the high noise, still photos don’t do it justice. The video quality is highly impressive for a system running with no IR illumination. The camera in question is the Runcam Night Eagle 2 , prized for its 0.00001 lux sensitivity. Black and white only, its capable of providing vision in moonlight and starlight conditions without external illumination. In this project, it’s hooked up to a monocle display designed for use with drone FPV setups. With lithium batteries and a charge circuit hooked up, and everything stuffed inside a compact 3D printed case, the final result is a portable, pocket

In a post-apocalyptic world, this is the hacker you want rebuilding society. He’s showing off a three-wheeled go-kart that pivots the cockpit as it steers . A hand crank mounted at the center of the vehicle pivots each of the three wheels in place, but keeps the driver facing forwards with a matching rotation. Hit up the video after the break to see it for yourself. The real question here is, how did he pull this off? The watermark on the video shows that this was published by [wo583582429], a user on Douyin (the platform known as TikTok in the US). We plied our internet-fu but were unable to track down the user for more of the juicy details we crave. If you have a lead on more info, leave it in the comments below. For now, please join us in speculating on this build. This is a pretty good closeup of one of the wheel assemblies. First question is how does the turning mechanism work? Since all three wheels and hub are smoothly coordinated it’s likely this is a planetary gearing setup

Ask someone who isn’t technically inclined how a TV signal works or how a cell phone works, or even how a two-way switch in a hall light works and you are likely to get either a blank stare or a wildly improbable explanation. But there are some things so commonplace that even the most tech-savvy of us don’t bother thinking about. One of these things is the lowly gas pump. Gas pumps are everywhere and it’s a safe bet to assume everyone reading this has used one at some point, most of use on a regular basis. But what’s really going on there? Most of it is pretty easy to figure out. As the name implies, there must be a pump. There’s some way to tell how much is pumping and how much it costs and, today, some way to take the payment. But what about the automatic shut off? It isn’t done with some fancy electronics, that mechanism dates back decades. Plus, we’re talking about highly combustible materials, there has to be more to it then just a big tank of gas and a pump. Safety is paramount

[Will Cogley] is slowly but surely crafting a beautiful bionic hand . (Video, embedded below.) The sheer amount of engineering and thought that went into the design is incredible. Those who take their hands for granted often don’t consider the different ways that their digits can move. There is lateral movement, rotation, flexion, and extension. Generally, [Will] tries to design mechanisms with parts that can be 3D printed or sourced easily. This constrains the hand to things like servos, cable actuation, or direct drive. However, the thumb has a particularly tricky range of motion. So for the thumb [Will] designed to use a worm geared approach to produce the flexing and extension motion of the thumb. These gears need to be machined in order to stand up to the load. A small side 3d printed gear that connects to the main worm gear is connected to a potentiometer to form the feedback loop. Since it isn’t bearing any load, it can be 3d printed. While there are hundreds of little tiny pro

When the news broke recently that communications had finally been re-established with Voyager 2 , I felt a momentary surge of panic. I’ve literally been following the Voyager missions since the twin space probes launched back in 1977, and I’ve been dreading the inevitable day when the last little bit of plutonium in their radioisotope thermal generators decays to the point that they’re no longer able to talk to us, and they go silent in the abyss of interstellar space. According to these headlines, Voyager 2 had stopped communicating for eight months — could this be a quick nap before the final sleep? Thankfully, no. It turns out that the recent blackout to our most distant outpost of human engineering was completely expected, and completely Earth-side. Upgrades and maintenance were performed on the Deep Space Network antennas that are needed to talk to Voyager. But that left me with a question: What about the rest of the DSN? Could they have not picked up the slack and kept us in tou

Thanksgiving is just round the corner and [mrak_ripple] was worried about serving food under social distancing conditions. Rather than bother with standard best practice, he chose to take a more exciting route – flinging side dishes with miniature siege weaponry. (Video, embedded below.) The mashed potato trebuchet is a build in the modern style, relying on 8020 aluminium extrusion to allow for quick and easy assembly. It also takes advantage of what appears to be a heavy duty laser cutter, which creates strong steel brackets to hold everything together. The launcher cup to hold the mash is a 3D printed part, created in resin and held on the end of the arm with duct tape, since appropriate bolts didn’t fall to hand. In the end, repeatability was a struggle, and we suspect the trebuchet won’t actually do food service on the holiday itself. However, it could certainly make for a fun game after dinner, seeing who can get the most mash onto a willing target. We’d love to see a mash cann

[James Bruton] is an impressive roboticist, building all kinds of robots from tracked, exploring robots to Boston Dynamics-esque legged robots. However, many of the robots are proof-of-concept builds that explore machine learning, computer vision, or unique movements and characteristics. This latest build make use of everything he’s learned from building those but strives to be useful on a day-to-day basis as well, and is part of the beginning of a series he is doing on building a Really Useful Robot . (Video, embedded below.) While the robot isn’t quite finished yet, his first video in this series explores the idea behind the build and the construction of the base of the robot itself. He wants this robot to be able to navigate its environment but also carry out instructions such as retrieving a small object from a table. For that it needs a heavy base which is built from large 3D-printed panels with two brushless motors with encoders for driving the custom wheels, along with a suspen

In the grand scheme of things, it really wasn’t all that long ago that a slide rule was part of an engineer’s every day equipment. Long before electronic calculators came along, a couple of sticks of wood inscribed with accurate scales was all it took to do everything from simple multiplication to logarithms and trig functions. While finding a slide rule these days isn’t impossible, it’s still not exactly easy, and buying one off the shelf isn’t as fun or as instructive as building one yourself . [JavierL90]’s slide rule build started, ironically enough, on the computer, with a Python program designed to graphically plot the various scales needed for the fixed sections of the slide rules (the “stators”) and the moving bit (the “slide”).  His first throught was to laser-engrave the scales, but the route of printing them onto self-adhesive vinyl stock proved to be easier. With the scale squared away, work turned to the mechanism itself. He chose walnut for the wood, aluminum for the br

There is a certain charm to older electronics gear. Heavy metal chassis and obviously hand-wired harness can be a work of art even if they would be economically impractical for most modern gear. Watching [msylvain59’s] tear down of a Collins 51R VOR receiver is a good example of that. The construction looks so solid. If you aren’t familiar with VOR, it stands for VHF omnidirectional range and allows airplanes to tune into a fixed ground-based beacon and determine its heading in relation to the beacon. In some cases, it can also calculate distance. Years ago, VOR antennas actually rotated rapidly, but today it is more likely to be an array of antennas switched electrically. The radio beam has several encoding schemes, including an FM reference signal that allows an airplane receiver — like the 51R — to determine the heading to the beacon. If you know the heading to two beacons, you can figure out where you are. Even with a single beacon, you can hold course towards it or away from it

A pen plotter is often the first experience many ambitious makers have of the world of Computer Numerical Control, or CNC. While they typically operate on flat stock, with the right build, they can be designed to draw on curved surfaces, too – as [tuenhidiy] demonstrates with this rotary bottle plotter. The plotter uses shafts salvaged from an old printer to act as the rollers for the bottle to be drawn upon, turned by a pair of stepper motors. X and Z axes are created out of two CD drive mechanisms – a popular way to build two linear axes on the cheap. The hardware is controlled by GRBL, running on an Arduino Uno kitted out with a CNC shield to handle the necessary I/O. The build is somewhat limited to by the short range of its X axis, which prevents the plotter from easily drawing on a full-size bottle label or can. However, this could easily be fixed with some upgrades and extra steppers if so desired. As a home build, it’s a great way to learn about the CNC techniques required t

It seems like every year, it gets a bit easier to build your own CNC. From the Enhanced Machine Controller (EMC) project of the early 1990s to Arduinos running Grbl in the late 2000s, the open source community has moved ahead in leaps and bounds. Grbl is at its core firmware that interprets G-code and commands stepper motors, usually to move a tool head in such a way as to make something. Tons of systems have been built around it, including early Makerbot printers. Its also spawned a plethora of other projects (the Grbl GitHib repo has 2,400 forks!), including a 32-bit flavor called grblHAL. This version is at the heart of a fantastic CNC controller board developed by [Phill Barrett] . Ditching the Arduino for a more powerful Teensy 4.1, [Phil]’s controller supports full five-axis control, variable frequency drive spindles, dust extractor control, and flood and mist coolant control. It can run at blazing stepping rates of up to 160 kHz (standard Grbl on an Arduino hits 30 kHz) and can

Ubuntu 20.04 is an incredibly popular operating system, perhaps the most popular among the Linux distributions due to its ease-of-use. In general, it’s a fairly trustworthy operating system too, especially since its source code is open. However, an update with the 20.04 revision has led to security researcher [Kevin Backhouse] finding a surprisingly easy way to escalate privileges on this OS , which we would like to note is not great. The exploit involves two bugs, one in accountservice daemon which handles user accounts on the computer, and another in the GNOME Display Manager which handles the login screen. Ubuntu 20.04 added some code to the daemon which looks at a specific file on the computer, and with a simple symlink, it can be tricked into reading a different file which locks the process into an infinite loop. The daemon also drops its privileges at one point in this process, a normal security precaution, but this allows the user to crash the daemon. The second bug for this

After a couple of months away we’re returning with our periodic roundup of happenings in orbit, as we tear you away from  Star Trek: Discovery and  The Mandalorian , and bring you up to date with some highlights from the real world of space. We’ve got a launch to look forward to this week, as well as a significant anniversary. The ISS as it looked twenty years ago. NASA (Crew of STS-106), Public domain . A quiet but extremely significant anniversary first up: in the week that this is being written we’ve passed the 20-year anniversary of a continuous human presence in space aboard the ISS . The geopolitical map of the world may have swirled around down on the surface over the last couple of decades, but American, Russian, Canadian, European, and Japanese astronauts and cosmonauts with all their modules and experiments have continually passed over our heads in an island of international harmony and scientific endeavour. There appears to be political uncertainty over how long the sta