Old-School Video Switching Levels Up With Modern USB Control

December 10, 2022 by Donald Papp 13 Comments

Video effects and mixing are done digitally today, but it wasn’t always so. When analog ruled the video world, a big switch panel was key to effective results.

VIdeo like this was the result of combining different analog feeds with different effects. The better the hardware, the more was possible.

Devices like [Glen]’s Grass Valley Series 300 Crosspoint Switch Panel were an important part of that world. With tools like that, a human operator could set up a composited preview feed in true WYSIWYG style, and switch to live on cue. All done with relatively simple CMOS ICs and buttons. Lots and lots of buttons.

[Glen] reverse engineers the panel to show how it works, and most of the heavy lifting is done by the MC14051B analog multiplexer/demultiplexer, and the MC14532B 8-bit priority encoder. Once that’s figured out, the door is open to modernizing things a little by using a microcontroller to drive the device, turning it into a USB peripheral.

With a little design work, [Glen] builds a PCB around the EFM8UB2 8-bit microcontroller to act as a USB peripheral and control the switch panel, taking care of things like key scanning and lamp control. The last step: a GUI application for monitoring and controlling the panel over USB.

This isn’t [Glen]’s first time interfacing to vintage video mixing and switching, and as many of us know it’s sometimes tricky work to interface to existing hardware. We covered his earlier video switcher project using hardware that was not nearly as easy to work with as this one.

Flipper Zero Hacker Tool Gets UI Editor For Custom Apps

December 10, 2022 by Donald Papp 12 Comments

[Mikhail] released a handy GUI editor/generator tool for the Flipper Zero multipurpose hacker tool, making layouts and UI elements much easier and more intuitive to craft up.

Those who decide to delve into rolling their own applications or add-ons will find this a handy resource, especially as it generates the necessary code for the visual elements. It’s not limited to placing icons, either. Boxes, lines, dots, text, and more can be freely laid out to get things looking just right.

To use it, simply drag and drop icons of various sizes into the screen area. Non-icon UI elements like frames, lines, text, and others can be placed with a click using the buttons. To move elements around, click the SELECT button first, then drag things as needed. To fine-tune positioning (or change the text of a string) a selected element’s properties can be accessed and modified to the right of the simulated screen. When things look good, switch to the CODE tab and copy away to use it in your Flipper application.

Unfamiliar with the Flipper Zero? It’s a kind of wireless multitool; a deeply interesting device intended to make wireless exploration and experimentation as accessible as its dolphin mascot is adorable.

Cardboard Game Tokens Become Shiny Click-Clacks With DIY Treatment

November 30, 2022 by Donald Papp 30 Comments

Tabletop games and cardboard tokens go hand-in-hand for a good reason: they are economical and effective. However, their tactile attributes leave a little to be desired. There’s something really great about high-quality pieces possessing a shiny, pleasing smoothness and click-clack handling that cardboard simply can’t deliver, but that all changes with [Dzhav]’s simple method for converting cardboard tokens into deluxe versions of themselves with a little work and a resin coating.

The result is a token with a crystal-clear, smooth, and slightly-convex coating of hardened resin on it. They feel (and sound) like plastic, rather than cardboard. The resin used is a two-part clear jewelry resin, used for casting things like pendants. It benefits from a long working time and unlike UV-cured resin (like the SLA 3D printer resin) it won’t be affected by light.

Careful application of resin relies on surface tension to prevent messes.

Like with most things, good results come from careful preparation and technique. [Dzhav] suggests preparing the tokens by sanding the edges completely smooth with fine sandpaper, then using a black marker to color them. Then, tokens are coated one side at a time with a paintbrush and correctly-mixed resin: while holding a token down with a toothpick, resin is brushed right to (but not over) the edges. Then, additional resin can be dropped in the center of the token, and gravity and surface tension will work together to ensure an even coating that doesn’t drip.

After the resin has had plenty of time to cure, the tokens are flipped over and the process repeated. The end result are tokens with both sides coated in a nice, smooth, ever-so-slightly-convex shield of resin.

They look fantastic, and sound even better. Turn up your volume and play the two-second video embedded below to listen for yourself. And when you’re ready for another gamer that didn’t settle for what was in the box, check out this redesigned Catan version.

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Making 3D Print Time-lapses With Old Earphones And A Few Spare Parts

November 30, 2022 by Donald Papp 18 Comments

The trick to producing great 3D printing time-lapse animations is to ensure that the extruder has moved out of the frame each time a photo is taken — which usually requires OctoPrint to be controlling both the camera and printer. But [NirL] managed to bodge up a system to get the same result with a spare limit switch, a resistor, his mobile phone, and an old set of earbuds. Not bad for some spare parts and a little extra G-Code.

The print head hits a remote shutter button during a brief parking action after each layer.

Inserting custom G-Code to park the print head at regular intervals takes care of standardizing the printer’s movements; there’s even a post-processing extension in Cura that makes this easy. As for triggering the camera, [NirL] was inspired by the remote shutter button on a selfie stick. By positioning a physical switch in such a way that the print head pushes it every time it (briefly) parks, a photo gets taken for every layer. Essentially the same thing Octolapse does, just with fewer parts.

To create the DIY remote shutter button, [NirL] used a spare limit switch, resistor, and cannibalized an old set of earbuds for the cable and 4-conductor 3.5 mm audio plug. Most phones and camera apps trigger the shutter when they receive a Vol+ signal through the audio plug, which is done by connecting MIC and GND through a 240 Ohm resistor.

In this way a photo is snapped for every layer, giving [NirL] all that is needed to assemble a smooth animation. Sure, it ties up a mobile phone for the duration of the print, but for just a few spare parts it does the job. You can see the project in action in the video, embedded just under the page break.

As mentioned, the usual way to implement effortless time-lapses is by using the Octolapse plugin for OctoPrint, which creates silky smooth animations without the typical blur of time-lapses.

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VR Sickness: A New, Old Problem

November 29, 2022 by Donald Papp 56 Comments

Have you ever experienced dizziness, vertigo, or nausea while in a virtual reality experience? That’s VR sickness, and it’s a form of motion sickness. It is not a completely solved problem, and it affects people differently, but it all comes from the same root cause, and there are better and worse ways of dealing with it.

If you’ve experienced a sudden onset of VR sickness, it was most likely triggered by flying, sliding, or some other kind of movement in VR that caused a strong and sudden feeling of vertigo or dizziness. Or perhaps it was not sudden, and was more like a vague unease that crept up, leaving you nauseated and unwell.

Just like car sickness or sea sickness, people are differently sensitive. But the reason it happens is not a mystery; it all comes down to how the human body interprets and reacts to a particular kind of sensory mismatch.

Why Does It Happen?

The human body’s vestibular system is responsible for our sense of balance. It is in turn responsible for many boring, but important, tasks such as not falling over. To fulfill this responsibility, the brain interprets a mix of sensory information and uses it to build a sense of the body, its movements, and how it fits in to the world around it.

These sensory inputs come from the inner ear, the body, and the eyes. Usually these inputs are in agreement, or they disagree so politely that the brain can confidently make a ruling and carry on without bothering anyone. But what if there is a nontrivial conflict between those inputs, and the brain cannot make sense of whether it is moving or not? For example, if the eyes say the body is moving, but the joints and muscles and inner ear disagree? The result of that kind of conflict is to feel sick.

Common symptoms are dizziness, nausea, sweating, headache, and vomiting. These messy symptoms are purposeful, for the human body’s response to this particular kind of sensory mismatch is to assume it has ingested something poisonous, and go into a failure mode of “throw up, go lie down”. This is what is happening — to a greater or lesser degree — by those experiencing VR sickness.

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Here’s A Plain C/C++ Implementation Of AI Speech Recognition, So Get Hackin’

November 27, 2022 by Donald Papp 19 Comments

[Georgi Gerganov] recently shared a great resource for running high-quality AI-driven speech recognition in a plain C/C++ implementation on a variety of platforms. The automatic speech recognition (ASR) model is fully implemented using only two source files and requires no dependencies. As a result, the high-quality speech recognition doesn’t involve calling remote APIs, and can run locally on different devices in a fairly straightforward manner. The image above shows it running locally on an iPhone 13, but it can do more than that.

Implementing a robust speech transcription that runs locally on a variety of devices is much easier with [Georgi]’s port of OpenAI’s *Whisper*.

[Georgi]’s work is a port of OpenAI’s Whisper model, a remarkably-robust piece of software that does a truly impressive job of turning human speech into text. Whisper is easy to set up and play with, but this port makes it easier to get the system working in other ways. Having such a lightweight implementation of the model means it can be more easily integrated over a variety of different platforms and projects.

The usual way that OpenAI’s Whisper works is to feed it an audio file, and it spits out a transcription. But [Georgi] shows off something else that might start giving hackers ideas: a simple real-time audio input example.

By using a tool to stream audio and feed it to the system every half-second, one can obtain pretty good (sort of) real-time results! This of course isn’t an ideal method, but the robustness and accuracy of Whisper is such that the results look pretty great nevertheless.

You can watch a quick demo of that in the video just under the page break. If it gives you some ideas, head over to the project’s GitHub repository and get hackin’!

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Simple Mod Lets Quadruped Robot Stand And Walk

November 19, 2022 by Donald Papp 9 Comments

When it comes to locomotion, robots don’t typically do more than one thing at a time. Walkers stick to walking, and rollers stick to rolling. However, this simple method of enabling a cheetah-style quadruped to stand and even walk a little is pretty clever.

With just a couple of rigid struts attached to the shins of the rear legs, it becomes possible for the robot to lever itself up into a stable standing position, and even shuffle around a bit. Not bad for a couple bolted-on bits with no moving parts!

The robot style will look pretty familiar to some of our readers. It does resemble Boston Dynamics’ Spot but it’s closer to the MIT Mini Cheetah, whose design and brushless motors made for eye-catching agility and speed. It has inspired not just countless DIY efforts, but also kits of parts from overseas sellers.

The image here should make it clear how it works, but take a moment to also watch the short video embedded just below the page break, and see the process in action from beginning to end.

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