Watch Blender Plugin Make Animated PCB Traces (and More)

November 30, 2021 by Donald Papp 3 Comments

[Staacks]’s Blender plugin to animate growth is behind the sweet animation seen above. It’s an add-on that cleverly makes creating slick growth animations easier when using Blender. It isn’t limited to PCB images either, although they do happen to make an excellent example of the process.

The add-on isn’t limited to animating PCB traces.

The idea is that one begins with an image texture with a structure showing a bunch of paths (like a maze, or traces on a PCB), and that gets used as an input. The plugin then uses a path finding algorithm to determine how these paths could grow from an origin point, and stores the relevant data in the color channels of an output image. That output is further used within Blender as the parameters with which to generate the actual animation, resulting in the neat self-creating PCB seen above. That PCB isn’t just for show, by the way. It’s the PCB for [Staacks]’s smart doorbell project.

Blender is an amazingly comprehensive tool for modeling and animation, and while we’ve covered using it to create high-quality KiCad renders, this kind of animation is really something else.

Here is the GitHub repository for the Blender growth tool if you’re interested in giving it a spin. If you’d like to see more first, watch the video embedded below for a showcase of what it’s capable of, and how it works.

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ESP32 board with battery and nearby antenna

How To Easily Set Up Secure OTA Firmware Updates On ESP32

November 29, 2021 by Donald Papp 12 Comments

After an electronic IoT device has been deployed into the world, it may be necessary to reprogram or update it. But if physical access to the device (or devices) is troublesome or no longer possible, that’s a problem.

OTA updates allow a device to download new firmware, install it, and reboot itself into the new version. Convenient? Yes. Secure? It definitely needs to be.

Fortunately, over-the-air (OTA) firmware updates are a thing, allowing embedded devices to be reprogrammed over their wireless data connection instead of with a physical hardware device. Security is of course a concern, and thankfully [Refik] explains how to set up a basic framework so that ESP32 OTA updates can happen securely, allowing one to deploy devices and still push OTA updates in confidence.

[Refik] begins by setting up a web server using Ubuntu Linux, and sets up HTTPS using a free SSL certificate from Let’s Encrypt, but a self-signed SSL certificate is also an option. Once that is done, the necessary fundamentals are in place to support deploying OTA updates in a secure manner. A bit more configuration, and the rest is up to the IoT devices themselves. [Refik] explains how to set things up using the esp32FOTA library, but we’ve also seen other ways to make OTA simple to use.

You can watch a simple secure OTA firmware update happen in the video, embedded below. There are a lot of different pieces working together, so [Refik] also provides a second video for those viewers who prefer a walkthrough to help make everything clear. Watch them both, after the break.

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Generate Fully Parametric, 3D-Printable Speaker Enclosures

November 28, 2021 by Donald Papp 9 Comments

Having the right speaker enclosure can make a big difference to sound quality, so it’s no surprise that customizable ones are a common project for those who treat sound seriously. In that vein, [zx82net]’s Universal Speaker Box aims to give one everything they need to craft the perfect enclosure.

The parts can be 3D-printed, but the design ensures that the front and back panels are flat, so one can use wood or some other material for those depending on preference and appearance. The assembly is screwed together using six M3 bolts per side with optional heat-set inserts, but it’s entirely possible to simply glue the unit together if preferred.

One thing that makes this design a bit more broadly useful is that [zx82net] not only provides the parametric design file for Fusion360, but also includes STEP format CAD files, and a small number of pre-configured assemblies for a few commonly available speaker drivers: the Dayton Audio DMA70-4, ND91-4, and the TCP115-4. Not enough for you? Check out [zx82net]’s collection of ready-to-rock enclosures in a variety of designs and configurations; there’s bound to be something to appeal to just about anyone.

[via Reddit]

Want Octoprint But Lack A Raspberry Pi? Use An Old Android Phone

November 27, 2021 by Donald Papp 21 Comments

3D printers and Octoprint have a long history together, and pre-built images for the Raspberry Pi make getting up and running pretty easy. But there’s also another easy way to get in on the Octoprint action, and that’s to run it on an Android phone with the octo4a project.

A modern smartphone has a lot of useful features that make it attractive as an Octoprint host. There is a built-in touchscreen, easy power management, a built-in camera, and the fact that people regularly upgrade to new phones means that older Android phones — still powerful pieces of hardware in their own right — are readily available at low cost. The project is still relatively new, so don’t forget to check the Octoprint community thread for this project if you give it a try.

If you are wondering what Octoprint is and what it brings to the table, our own Tom Nardi explained what it does and why it matters when he shared his own upgrade experience from 2018. A few details are no longer current — for example one is no longer likely to encounter a Printrbot — but it’s still a perfectly valid primer on adding great management functionality to a 3D printer.

Magic In VR That Depends On Your Actual State Of Mind

November 21, 2021 by Donald Papp 10 Comments

[Cangar]’s excitement is palpable in his release of a working brain-computer interface (BCI) mod for Skyrim VR, in which the magic system in the game is modified so that spell effectiveness is significantly boosted when the player is in a focused mental state. [Cangar] isn’t just messing around, either. He’s a neuroscientist whose research focuses on assessing mental states during task performance. Luckily for us, he’s also an enthusiastic VR gamer, and this project of his has several interesting aspects that he’s happy to show off in a couple of videos.

User wearing VR headset — The Muse 2 fits under the VR headset easily.

It all starts with the player wearing a Muse 2 meditation device; a type of passive, off-the-shelf electroencephalography (EEG) unit aimed primarily at guiding a user towards better relaxation and focus. [Cangar] reads data using the Brainflow library and processes it into a final value on a scale between “not focused” and “focused”. [Cangar] makes a point of explaining that his system ultimately has the goal of modeling the player’s state of mind, which is different from modeling just the brain activity. As such, motion data is considered as well, and holding still confers a small bonus to the process.

How is this data actually used in the game? In VR, this “focus” value is shown as a small bar on the player’s wrist, and spell effectiveness (for example, damage for attack spells) scales along with the size of the bar. When the bar is full a player would be very powerful, with spells doing double damage. If the bar is empty, spells will do little to no damage.

[Cangar] demonstrates the mod in two videos (both embedded below), but you won’t see him blasting enemies with fireballs. Presumably, VR gamers already know what that looks like, so what he does instead is explain how the system looks and works (first video, cued to 4:12), and in the second, he video demonstrates how the focus meter changes depending on his activity and mental state.

The results look exciting, and the potential uses of a system like this are pretty interesting to think about. Taking a few deep breaths and calming one’s body and mind before launching a magical attack will have a tangible effect in the world, and because things rarely go according to plan, there is also a clear survival benefit to learning to focus while under pressure. But if a brain monitor isn’t your cup of tea, maybe consider a leisurely bike ride through Skyrim, instead.

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Hexagonal Mirror Array Hides Hidden Message

November 14, 2021 by Donald Papp 18 Comments

[Ben Bartlett] recently got engaged, and the proposal had a unique bit of help in the form of a 3D-printed hexagonal mirror array, whose mirrors are angled just right to spell out a message with the reflections. A small test is shown above projecting a heart, but the real deal was a bigger version reflecting the message “MARRY ME?” into sand at sunset. Who could say no to something like that? Luckily for all of us, [Ben] shared all the details of what went into designing and building such a thoughtful and fascinating device.

Mirrors on the 3D-printed array are angled just right to reflect light into a message.

Essentially, the array of mirrors works a bit like a projector. Each individual reflection can be can be thought of as a pixel, and the projected position of each can be modified by the precise angle of each mirror. With the help of some Python code, [Ben] calculated the exact angles needed to spell out “MARRY ME?” and generated the necessary 3D model. A smaller-scale test (shown in the header image above) was successful, and after that it was just a matter of printing the array and gluing on some mirrors.

Of course, that’s the short version. In practice there were quite a few troublesome issues that demonstrated the value of using early tests to discover hidden problems. For one thing, mirror angle and alignment is crucial, which meant that anything that could affect the shape of the array was a potential problem. Glue that expands or otherwise changes shape as it dries or cures could slightly change a mirror’s angle, so cyanoacrylate (CA) glue was preferred. However, the tiniest bit of CA glue will mess up a mirror’s surface in a hurry, so care was needed during assembly.

The gleaming hexagonal mirrors are reminiscent of the James Webb Space Telescope.

Another gotcha was when [Ben] suddenly realized, twenty hours into printing the final assembly, that the message needed to be reversed! As designed, the array he was printing would project “?EM YRRAM” and this wasn’t caught during testing because the test pattern (a heart) was symmetrical. Fortunately there was time to correct the error and start again, but it was close. [Ben]’s code has an optional visualization function, which was invaluable for verifying that things would actually turn out as expected. As it happens, the project took right up to the last minute to complete and there wasn’t quite time to check everything 100% before the big moment, but it all turned out alright. What’s life without a little mystery and danger, anyway?

The pictures are great, but you won’t regret taking the time to read through the project page (don’t miss the annotated Python code) because [Ben] goes into just the right level of detail. The end result looks fantastic, and makes an excellent keepsake with a charming story.

Those Bullet Effects In Terminator 2 Weren’t CGI

November 14, 2021 by Donald Papp 25 Comments

Remember Terminator 2? Guns were nearly useless against the murderous T-1000, played by Robert Patrick. Bullets fired at the “liquid metal” robot resulted only in a chrome-looking bullet splash that momentarily staggered the killing machine. The effects were done by Stan Winston, who died in 2008, but a video and short blurb shared by the Stan Winston School of Character Arts revealed, to our surprise and delight, that the bullet impact effects were not CGI.

How was this accomplished? First of all, Winston and his team researched the correct “look” for the splash impacts by firing projectiles into mud and painstakingly working to duplicate the resulting shapes. These realistic-looking crater sculpts were then cast in some mixture of foam rubber, and given a chromed look by way of vacuum metallizing (also known as vacuum deposition) which is a way of depositing a thin layer of metal onto a surface. Vacuum deposition is similar to electroplating, but the process does not require the object being coated to have a conductive surface.

These foam rubber splash patterns — which look like metal but aren’t — were deployed using a simple mechanical system. A variety of splashes in different sizes get individually compressed into receptacles in a fiberglass chest plate. Covering each is a kind of trapdoor, each held closed by a single pin on a cable.

To trigger a bullet impact effect, a wireless remote control pulls a cable, which pulls its attached pin, and the compressed splash pattern blossoms forth in an instant, bursting through pre-scored fabric in the process. Sadly there are no photos of the device itself, but you can see it in action in the testing video shared by the Stan Winston School, embedded below.

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