Automatic Turntable Makes Photogrammetry A Cinch

April 28, 2022 by Lewin Day 9 Comments

Photogrammetry is a great way to produce accurate 3D models of real objects. A turntable is often a common tool used in this work as it helps image an object from all angles. [Peter Lin] wanted a way to run the photogrammetry process with minimal human intervention, and set about building an automated turntable setup.

The build relies on a smartphone to take images of the physical object. The phone is triggered to take photos by an ESP8266, which fires the shutter via the phone’s audio socket. The microcontroller then turns the turntable on for a short period of time after each shot, rotating it by a set angle.

The build still requires objects to be repositioned in various orientations on the turntable now and then, in order to capture the top and bottom areas that would otherwise be obscured. However, the grunt work of taking the photos and rotating the objects is now entirely automated.

It’s a useful build for anyone that finds themselves regularly imaging objects to create 3D models. The results of [Peter]’s rig look great, and as a bonus come with life-like textures ready to go. We’ve seen some other great photogrammetry builds before, too. Video after the break.

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EV Charging Connectors Come In Many Shapes And Sizes

April 28, 2022 by Lewin Day 69 Comments

Electric vehicles are now commonplace on our roads, and charging infrastructure is being built out across the world to serve them. It’s the electric equivalent of the gas station, and soon enough, they’re going to be everywhere.

However, it raises an interesting problem. Gas pumps simply pour a liquid into a hole, and have been largely standardized for quite some time. That’s not quite the case in the world of EV chargers, so let’s dive in and check out the current state of play.

AC, DC, Fast, or Slow?

Since becoming more mainstream over the past decade or so, EV technology has undergone rapid development. With most EVs still somewhat limited in range, automakers have developed ever-faster charging vehicles over the years to improve practicality. This has come through improvements to batteries, controller hardware, and software. Charging tech has evolved to the point where the latest EVs can now add hundreds of miles of range in under 20 minutes.

However, charging EVs at this pace requires huge amounts of power. Thus, automakers and industry groups have worked to develop new charging standards that can deliver high current to top vehicle batteries off as quickly as possible.

As a guide, a typical home outlet in the US can deliver 1.8 kW of power. It would take an excruciating 48 hours or more to charge a modern EV from a home socket like this.

In contrast, modern EV charge ports can carry anywhere from 2 kW up to 350 kW in some cases, and require highly specialized connectors to do so. Various standards have come about over the years as automakers look to pump more electricity into a vehicle at greater speed. Let’s take a look at the most common options out in the wild today. Continue reading “EV Charging Connectors Come In Many Shapes And Sizes” →

DIY Arduino Based EV Charger Saves Money, Looks Pro

April 28, 2022 by Ryan Flowers 56 Comments

Electric vehicles (EVs) are something of a hot topic, and most of the hacks we’ve featured regarding them center on conversions from Internal Combustion to Electric. These are all fine, and we hope to see plenty more of them in the future. There’s another aspect that doesn’t get covered as often: How to charge electric vehicles- especially commercially produced EV’s rather than the DIY kind. This is the kind of project that [fotherby] has taken on: A 7.2 kW EV charger for his Kia.

Faced with spending £900 (about $1100 USD) for a commercial unit installed by a qualified electrician, [fotherby] decided to do some research. The project wasn’t outside his scope, and he gave himself a head start by finding a commercial enclosure and cable that was originally just a showroom unit with no innards.

An Arduino Pro Mini provides the brains for the charger, and the source code and all the needed information to build your own like charger is on GitHub. What’s outstanding about the guide though is the deep dive into how these chargers work, and how straightforward they really are without being simplistic.

Dealing with mains power and the installation of such a serious piece of kit means that there are inherent risks for the DIYer, and [fotherby] addresses these admirably by including a ground fault detection circuit. The result is that if there is a ground fault of any kind, it will shut down the entire circuit at speeds and levels that are below the threshold that can harm humans. [fotherby] backs this up by testing the circuit thoroughly and documenting the results, showing that the charger meets commercial standards. Still, this isn’t a first-time project for the EV enthusiast, so we feel compelled to say “Don’t Try This At Home” even though that’s exactly what’s on display.

In the end, several hundred quid were saved, and the DIY charger does the job just as well as the commercial unit. A great hack indeed! And while these aren’t common, we did cover another Open Source EV charger about a year ago that you might like to check out as well.

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90s Apple Computer Finally Runs Unsigned Code

April 28, 2022 by Bryan Cockfield 12 Comments

Back in the 90s, the console wars were in full swing. Nintendo vs Sega was an epic showdown at first, but when Nintendo seemed sure to clench the victory Sony came out of nowhere with the PlayStation. While these were the most popular consoles at the time, there were a few others around that are largely forgotten by history even if they were revolutionary in some ways. An example is the Pippin, a console made by Apple, which until now has been unable to run any software not signed by Apple.

The Pippin was Apple’s only foray into gaming consoles, but it did much more than that and included a primitive social networking system as well as the ability to run Apple’s Macintosh operating system. The idea was to be a full media center of sorts, and the software that it would run would be loaded from the CD-ROM at each boot. [Blitter] has finally cracked this computer, allowing it to run custom software, by creating an authentication file which is placed on the CD to tell the Pippin that it is “approved” by Apple.

The build log goes into incredible detail on the way these machines operated, and if you have a Pippin still sitting around it might be time to grab it out of the box and start customizing it in the way you probably always wanted to. For those interested in other obscure Apple products, take a look at this build which brings modern WiFi to the Apple Newton, their early PDA.

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Drone Filming Chile’s Urban Bike Race Takes Some Fancy Radio Gear

April 27, 2022 by Lewin Day 13 Comments

Drones have revolutionized the world of videography in perhaps the biggest way since the advent of digital hardware. They’re used to get shots that are impractical or entirely impossible to get by any other means. The [Dutch Drone Gods] specialize in such work. When it came to filming an urban mountain bike race in a dense Chilean city, they had to bust out some serious tricks.

The FPV video feed was grainy, but good enough to keep the pilot on track. The drone carried a separate second camera for capturing high-quality footage of the run.

Typically, running a drone chase cam behind a biker would require some good first-person flying skills and a quick drone. However, for the Red Bull Valparaiso Cerro Abajo urban downhill event, this alone would not be enough. The tight course winds down staircases between thick concrete walls and even through houses, presenting huge challenges to maintaining signal integrity. Without a clear video signal, the pilot can’t fly the drone without crashing.

To make this all possible, the team used a variety of techniques to help combat the uncooperative radio environment. Directional antennas were used to target different sections of the course. Additionally, a second drone was flown high above the course carrying a radio repeater, helping provide a better line-of-sight contact to the camera drone following the riders when the buildings would otherwise block the signal to the pilot.

Even with all this work, the signal was still scratchy and would cut out at some points. However, with a bit of blind faith when cutting through the worst areas, the [Dutch Drone Gods] and the [Red Bull] team were able to put together an amazing FPV drone shot shadowing [Tomas Slavik] on his run down the extremely difficult urban course.

Details on the precise hardware are scarce. However, it’s something that any experienced drone builder could probably whip up without too much trouble. The idea of using a drone-based repeater is particularly exciting, and something we’re sure could help out many pilots who find themselves operating in difficult urban environments.

We’ve seen plenty of great FPV stories over the years, from early experiments in the 1980s to fun DIY cockpit builds of today. Video after the break.

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CAD Sketcher, It’s Parametric CAD For Blender

April 27, 2022 by Anne Ogborn 37 Comments

It’s very early days for CAD Sketcher, a new parametric CAD add-on for Blender by [hlorus], but it looks very promising.

We do a lot of 3D work and like Blender as an environment. It’s always annoying that Blender doesn’t do parametric modeling, so we’re forced into a dedicated CAD package. Blending the two for that robot ocelot is always particularly annoying.

CAD Sketcher lets the user make a ‘sketch’, a 2D drawing. They then constrain it, saying “this line is vertical, that line is parallel to this one”, until the sketch is fully defined. It’s a normal part of parametric modelling. This is powerful when your model needs refined over and over.

There’s an old adage, “Better a tool that does 90% of the job well than one that does 100% poorly”. For CAD systems, (and much other software), we’d suggest “Better a tool that does 90% of the job well and works with whatever does the other 10%”.

3D render of gaurd — Guard Drawn In CAD Sketcher And Blender

We tried a test part, and being in Blender’s universe showed its value. CAD Sketcher doesn’t do bevels and rounds yet, and probably won’t for a while. But Blender’s perfectly happy doing them.

It’s not going to put SolidWorks out of business any time soon, but it’s a very promising new development. We hope it gathers some community and encourage contributions.

We cover CAD frequently, like the recent advances with CadQuery and the port of OpenSCAD to WASM.

[thanks paulvdh]

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Digital To Analog In The Darkroom

April 27, 2022 by Bryan Cockfield 7 Comments

As the world becomes more and more digital, there are still a few holdouts from the analog world we’ve left behind. Vinyl records are making quite the comeback, and film photography is still hanging on as well. While records and a turntable have a low barrier for entry, photography is a little more involved, especially when developing the film. But with the right kind of equipment you can bridge the gap from digital to analog with a darkroom setup that takes digital photographs and converts them to analog prints.

The project’s creator, [Muth], has been working on this project since he found a 4K monochrome display. These displays are often used in resin 3D printers, but he thought he could put them to use developing photographs. This is much different from traditional darkroom methods, though. The monochrome display is put into contact with photo-sensitive paper, and then exposed to light. Black pixels will block the light while white pixels allow it through, creating a digital-to-analog negative of sorts. With some calibration done to know exactly how long to expose each “pixel” of the paper, the device can create black-and-white analog images from a digital photograph.

[Muth] notes that this method isn’t quite as good as professional print, but we wouldn’t expect it to be. It creates excellent black-and-white prints with a unique method that we think generates striking results. The 4K displays needed to reproduce this method aren’t too hard to find, either, so it’s fairly accessible to those willing to build a small darkroom to experiment. For those willing to go further, take a look at some other darkroom builds we’ve seen in the past.

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