A Pull Chain To End Your Zoom Pain

Yay! Another videoconference call is in the books, so that must mean that it’s time to fumble around awkwardly for the hang-up button with a fading smile. [lanewinfield] knew there had to be a better way, and looked to the pull chain switch for salvation. Sure, this could just as easily be a button, but what’s the fun in that? Besides, few buttons would be as satisfying as pulling a chain to a Zoom call.

The pull chain switch is connected to an Adafruit Feather nRF52840 Express that’s emulating a Bluetooth keyboard. Firmware-wise it sends command + F6, which triggers an AppleScript that manually exits and and all Zoom calls and kills Chrome tabs pointed to meet.google.com. He’s using Apple’s hotkey wizard Alfred, but this could be handled just as easily with something like AutoHotKey.

Pull chain switches are neat little mechanisms. The chain is connected to a cam that engages a wheel with copper contacts on half the outside. When you pull the chain, the wheel moves 90° and the wheel contacts connect up with the fixed contacts inside the housing to make a connection. Pulling the chain again moves the wheel which slides to the half without the contacts. Check it out in the video below.

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The World Is Your Green Screen

This year has been the year of home video conferencing. If you are really on the ball, you’ve managed to put some kind of green screen up so you can hide your mess and look as though you are in your posh upper east side office space. However, most of the consumer video conferencing now has some way to try to guess what your background is and replace it even without a green screen. The results, though, often leave something to be desired. A recent University of Washington paper outlines a new background matting procedure using machine learning and, as you can see in the video below, the results are quite good. There’s code on GitHub and even a Linux-based WebCam filter.

The algorithm does require a shot of the background without you in it, which we imagine needs to be relatively static. From watching the video, it appears the acid test for this kind of software is spiky hair. There are several comparisons of definitely not bald people flipping their hair around using this method and other background replacers such as the one in Zoom.

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Zoom Control Box Helps Keep Meetings On Track

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. If you’ve built your own time-saving control console, be sure to let us know!

STM32 Gets Up Close And Personal With Mandelbrot

The Mandelbrot set is a curious mathematical oddity that, while interesting in its own right, is also a useful tool for benchmarking various types of computers. Its constant computing requirement when zooming in and out on the function, combined with the fact that it can be zoomed indefinitely, means that it takes some quality hardware and software to display it properly. [Thanassis] has made this a pet project of his, running Mandelbrot set visualizations in different ways on many different hardware platforms.

This particular one is based on an STM32 board called the Blue Pill, which [Thanassis] chose because he hadn’t yet done a continuous Mandelbrot zoom on a microcontroller yet. The display is handled by a tiny 16K IPS color screen, and some clever memory tricks had to come into play in order to get smooth video output since the STM has only 20 kB available. The integer multiplication is also tricky on a platform this small while keeping the continuous zoom function, so it’s limited to fixed point multiplication.

Even with the limitations of the platform, he is still able to achieve nearly double-digit FPS rates with this one. If you want to play around with graphics like this on an STM platform, [Thanassis] has released all of the source code on his GitHub page, but if you’d like to see more Mandelbrot manipulation you can check out one of his older projects where he built a similar project on an FPGA.

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Teleconferencing Like It’s 1988: Connecting Vintage Hardware To Zoom

Hang up your car phone and toss that fax machine in the garbage. Even back in the late 80s it was possible to do away with these primitive technologies in favor of video conferencing, even though this technology didn’t catch on en masse until recently. In fact, Mitsubishi released a piece of video conferencing equipment called the VisiTel that can be put to use today, provided you can do a bit of work to get it to play along nicely with modern technology.

[Alex] was lucky enough to have one of these on hand, as soon as it was powered up he was able to get to work deciphering the messaging protocol of the device. To do this he showed the camera certain pictures with known properties and measured the output waveforms coming from the device, which were AM modulated over an RJ9 connection which he had changed to a 3.5 mm headphone jack.

It communicates in a series of pictures instead of sending an actual video signal, so [Alex] had a lot of work to do to properly encode and decode the stream. He goes into incredible detail on his project page about this process and is worth a read for anyone interested in signal processing. Ultimately, [Alex] was able to patch this classic piece of technology into a Zoom call and the picture quality is excellent when viewed through the lens of $399 80s technology.

We have been seeing a lot of other hacks around video conferencing in the past six months as well, such as physical mute buttons and a mirror that improves eye contact through the webcam.

Mirror, Mirror, On Your Cam, Show Us What You’ve Drawn By Hand

Working and learning from home may be the new norm, and if IKEA shelves are any indication, folks are tricking out their home office with furniture, gadgets, and squishy chairs. While teleconferencing has proven to be an invaluable tool, paper documents aren’t going down with out a fight.

Unfortunately dedicated document cameras require significant space and monies, so they’re impractical if you only share once in a while. [John Umekubo] didn’t want students and teachers hobbled by the same costs and inconveniences, so he modeled a mirror holder that slides over a laptop’s webcam and directs the view downward.

[John]’s adventures started with a Twitter post, as seen below, but the responses were so encouraging that he published his design on Thingiverse for everyone. There’s also a version that can be laser cut out of cardboard, though we imagine a pair of scissors would work in a pinch. He admits there’s already a consumer model, but wasn’t planning to sell them anyway. Like us, he wants to get people to share their work.

We recently covered a simpler version of the same idea in use at Northwestern University, and we’ve seen a similar hack that gives a split-screen effect to sketch and maintain eye contact. If you want to share the view in your room, we have a Raspberry Pi streaming option that’s worth checking out.

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Distance Learning Land

[familylovermommy] has been homeschooling her kids even before the pandemic, so she’s pretty well-versed on being a learning coach and a teacher. One of the activities she designed for her boys has them creating 3D models using Tinkercad. In the spirit of openness and cultivating freethinking, she did not give them very many constraints. But rather, gave them the liberty to creatively design whatever scene they imagined.

In the Instructable, she shares her sons’ designs along with instructions to recreate the models. The designs as you’ll see are pretty extensive, so she embedded the Tinkercad designs directly into it. You can even see a number of video showcases as well.

This is a really cool showcase of some pretty stellar workmanship. Also, maybe a bit of inspiration for some of our readers who are creating work from home activities of their own.

While you’re at it, check out some of these other work-from-home hacks.

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