An Open Source Modular Flexure Construction Set

November 22, 2022 by 14 Comments

Flexures are one of those innocent-looking mechanisms that one finds inside practically any kind of consumer device. Providing constrained movements with small displacements, complete with controlled tension, they can be rather tricky to design. GrabCAD designer [Vyacheslav Popov] hails from Ukraine, and due to the current situation there, plans to sell a collection of flexure building blocks became difficult. In the end, [Vyacheslav] decided to generously release his work open source, for all to enjoy. This collection is quite extensive, looking like it could solve a huge variety of flexure design problems. (Links to the first three sets: Set00, Set01, Set02 but check the author’s collection page for many others)

It’s not just those super-cheap mechanisms in throw-away gadgets that leverage flexures, it’s much more. The Mars rovers use flexure-based suspension, scientific instruments (interferometers and the like) make use of them for small motions where specific axis constraints are needed, and finally, MEMS accelerometers and gyroscopes are based entirely upon them. We’re not even going to try to name examples of flexures in the natural world. They’re everywhere. And, now we’ve got some more design examples to use, so why not flex your flexure muscles and send one to the 3D printer and have a play?

We see flexures here quite a bit, like this nice demonstration of achievable accuracy. Flexures can make some delicious mechanisms, and neat 3D printable input devices.

Thanks to [Addison] for the tip!

Spoofing LIDAR Could Blind Autonomous Vehicles To Obstacles

November 22, 2022 by 74 Comments

Humans manage to drive in an acceptable fashion using just two eyes and two ears to sense the world around them. Autonomous vehicles are kitted out with sensor packages altogether more complex. They typically rely on radar, lidar, ultrasonic sensors, or cameras all working in concert to detect the road conditions ahead.

While humans are pretty wily and difficult to fool, our robot driving friends are less robust. Some researchers are concerned that LiDAR sensors could be spoofed, hiding obstacles and tricking driverless cars into crashes, or worse.

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If Your Drone Flies, Eat It!

November 22, 2022 by 29 Comments

Over the years we’ve featured countless drone projects here at Hackaday, fixed wing, rotary wing, multi-rotor, and more. Among them all we think there may be a type that we’ve never seen, but that is about to change as it’s the first time we’ve brought you an edible drone.

Why might you need an edible drone, you ask? It’s not to conceal the evidence after closing an airport — instead it’s a research project from the Swiss Federal Institute of Technology to produce an efficient means of bringing sustenance to stranded climbers. The St. Bernard dogs are out of a job, it’s now done the modern way!

Jokes aside, this is clearly an experimental craft, a fixed-wing monoplane whose wings are made from rice cakes and gelatin. A stranded climber could certainly munch away at those airofoils, but we’re guessing a real device would need something a little more nutritious while retaining the light cellular structure.

This may be our first edible drone, but it’s not the first piece of edible technology we’ve brought you.

a 3d printed case, sitting on a table with cactuses in the background, with a 3d rendered holo assistant reflected in a cone of polycarbonate sheets from a flat HDMI display pointed up

Anime Inspired Holographic Virtual Assistant

November 22, 2022 by 28 Comments

[Jessp] has created a very cute and endearing DIY virtual assistant called Maria. The build combines a 3D printed housing that uses a modern take on the “Pepper’s Ghost” illusion to render a virtual, three-dimensional anime inspired assistant that can take commands to get information about the weather, play music or set timers.

The hub houses a Raspberry Pi 4B and a 3.2 inch LCD HDMI screen mounted flat on its back to render the perspective corrected “Maria” character using a technique borrowed from the Pepper’s Cone project. Polycarbonate sheets are formed into a cone, allowing for the 3D effect of rendering the virtual assistant model. A consumer grade mini USB microphone is used to receive voice commands along with a consumer grade USB speaker for audio feedback. The virtual assistant offloads the text to speech services to Google Cloud, along with using a weather API and Spotify developer account to for its musical options.

All source code is available on [Jessp]’s GitHub page, including build instructions and STL files for the housing. We’ve featured open source voice assistants in the past, including Mycroft and a even a HAL-9000 virtual assistant (running Kalliope) but it’s nice to see further experimentation in this space.

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A Game Boy Advance – Downgraded!

November 21, 2022 by 6 Comments

We feature a large number of game console mods here, because enhancing the experience of using a classic machine often involves some really clever work. But here’s one that’s a bit different, instead of upgrading his Game Boy Advance, [Wenting Zhang] has downgraded it from a colour screen to a monochrome LCD. Take a look at the video below the break.

One might ask why this would be necessary, given that there are plenty of backlit colour LCD upgrades already for the GBA, but perhaps people who played the original might understand that it’s about improving the viewability over the rather poor-quality colour LCD original.

Interesting too is the choice of display controller. Where it might be expected to find an FPGA, instead there’s an PR2040. He goes into detail about its programming, and we hope it might inspire any others looking at screen transplants. Meanwhile if the name [Wenting Zhang] means anything to you, it should be for his other work with mono LCDs.

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Better Air Quality Sensing With CO2

November 21, 2022 by 19 Comments

Measuring air quality, as anyone who has tried to tackle this problem can attest, is not as straightforward as it might seem. Even once the nebulous term “quality” is defined, most sensors use something as a proxy for overall air health. One common method is to use volatile organic compounds (VOCs) as this proxy but as [Larry Bank] found out, using these inside a home with a functional kitchen leads to a lot of inaccurate readings. In the search for a more reliable sensor, he built this project which uses CO2 to help gauge air quality.

Most of the reason that CO2 sensors aren’t used as air quality sensors is cost. They are much more expensive than VOC sensors, but [Larry] recently found one that was more affordable and decided to build this project around it. The prototype used an Arduino communicating over I2C to the sensor and an OLED screen, which he eventually put in a 3D printed case to carry around to sample CO2 concentration in various real-world locations. The final project uses a clever way of interfacing with the e-paper display that we featured earlier.

While CO2 concentration doesn’t tell the full story of air quality in a specific place, it does play a major role. [Larry] found concentrations as high as 3000 ppm in his home, which can cause a drop in cognitive function. He’s made some lifestyle changes as a result which he reports has had a beneficial impact. For human-occupied indoor spaces, CO2 can easily be the main contributor to poor air quality, and we’ve seen at least one other project to address this concern directly.

Portable ESP32 RGB Lasershow Has All The Trimmings

November 21, 2022 by 47 Comments

Perhaps there was a time when fancy laser effects were beyond those without the largest of bank accounts, but today they can be created surprisingly easily. [Corebb] shows us how with a neat unit using an off the shelf RGB laser module and mirror module, driven by a ESP32 with software designed to make it as easy as possible to use.

The video below the break is in Chinese so you’ll have to turn on the subtitles if you’re an Anglophone, and it takes us through the whole process. It’s mounted in an SLA 3D printed enclosure which neatly holds all the parts. The ESP32 module drives a couple of DACs which in turn drive the galvanometer motors through a pair of amplifiers.

Then the software allows all sorts of custom displays for your creative expression, including uploading quick sketches over WiFi. Beyond pretty patterns we see it mounted on a bicycle for a head-up display of speed and navigation info. Even if it does fall off and break at one point we can see that could be an extremely useful accessory.

All the code can be found in a GitHub repository should you wish to try for yourself. Meanwhile we’ve covered a lot of laser projector projects here in the past, including most recently this one using stepper motors in place of galvanometers.

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