Generating Motion Via Nitinol Wires

December 2, 2023 by 13 Comments

Generally, when we’re looking to build something that moves we reach for motors, servos, or steppers — which ultimately are all just variations on the same concept. But there are other methods of locomotion available. As [Jamie Matthews] demonstrates, Nitinol wires can be another way to help get things moving.

Nitinol is a type of metal wire made of nickel and titanium that is also known as “memory wire”, because it can remember its former shape and transition back to it with a temperature change. [Jamie] uses this property to create a simple hand that is actuated by pieces of wire sourced from Amazon. This is actually a neat way to go, as it goes some way to mimicking how our own hands are moved by our tendons.

[Jamie] does a great job of explaining how to get started with Nitinol and how it works in a practical sense. We’ve seen it put to some wacky uses before, too, such as the basis for an airless tire.

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LED Tester Also Calculates Resistor For Target Voltage

December 2, 2023 by 12 Comments

[mircemk] built a slick-looking LED tester with a couple handy functions built in. Not only can one select a target current to put through an LED, but by providing a target voltage, the system will automatically calculate the necessary series resistor. If for example the LED is destined for 14 V, this device will not only show how the LED looks at the chosen current, but will calculate the required resistor to get the same results on a 14 V system.

The buttons on the left control the target current and the voltage of the destination system. Once an LED is connected it will light up and the display indicates the LED’s forward voltage, the LED current, and the calculated series resistor value to obtain the same result at the selected target voltage. It’s a handy way to empirically dial in LED brightness values without needing to actually set up any particular test environment.

On the inside there’s little more than a handful of passive components, an Arduino, an LCD display, and a few buttons. This kind of tool reminds us of the highly clever component testers that hit the hobbyist scene years ago, showing what kind of advanced tricks a modern microcontroller is capable of with the right programming. (Here’s a look at how those work, if you’re interested in some deeper details.)

[mircemk] demonstrates his tool in the video, embedded below. We particularly like the attention he paid to the enclosure, giving it a very functional layout. It goes to show that when designing something, it’s never too early to consider enclosure and UI layout.

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Print Your Own Brain Lamp From MRI Data

December 1, 2023 by 12 Comments

MRIs generally fall somewhere on the scale from boring to stressful depending on why you’re having one and how claustrophobic you get. Regardless, they’re a wonderful diagnostic tool and they’ve saved thousands if not millions of lives over the years. In a fun use of the technology, [mandalaFractals] has shown us how to make a 3D-printed brain lamp using an MRI scan of the head.

The build starts with an off-the-shelf lamp base and a smart LED bulb as the light source, though you could swap those out as desired for something like a microcontroller, a USB power supply, and addressable LEDs if you were so inclined. The software package Slicer is then used to take an MRI brain scan and turn it into something that you can actually 3D print. It’ll take some cleaning up to remove artifacts and hollow it out, but it’s straightforward enough to get a decent brain model out of the data. Alternatively, you can use someone else’s if you don’t have your own scan. Then, all you have to do is print it in a couple of halves, and pop it on the lamp base, and you’re done!

It’s a pretty neat build. Who wouldn’t love telling their friends that their new brain lamp was an accurate representation of their own grey noodles, after all? It could be a fun gift next time Halloween rolls around, too!

Meanwhile, if you’ve got your own MRI hacks that you’ve been cooking up, don’t hesitate to let us know!

Cat-o-Matic 3000 Serves Your Feline Masters

December 1, 2023 by 8 Comments

When you have three cats and three humans, you have one problem: feeding them on a schedule without over or under feeding them. Even if there was only one human in the equation, the Cat-o-Matic 3000 would still be a useful tool.

Essentially, it’s a traffic light for cats — where green means you are go for feeding, and red means the cat was just fed. Yellow, of course, means the cat is either half-full or half-empty, depending on your outlook.

The brains of this operation is an ATmega88PA leftover from another project. There’s a no-name voltage regulator that steps up the two AA cells to 5 volts. Timing comes from a 32 kHz crystal that allows the microcontroller to stay in power-saving sleep mode for long periods of time.

Creator [0xCAFEAFFE] says the firmware was cobbled together from other projects. Essentially, it wakes up once per second to increment the uptime counter and then goes back to sleep. Short-pressing a button shows the feeding status, and long-pressing it will reset the timer.

Wanna make a cat status indicator without electronics? Give flexures a try.

Robot Pianist Runs On Arduino Nano

December 1, 2023 by 7 Comments

The piano has been around for a long time now. Not long after its invention, humans started contemplating how they could avoid playing it by getting a machine to do the job instead. [vicenzobit] is the latest to take on this task, building a “Robot Pianista” that uses a simple mechanism to play a tune under electronic command (Spanish language, Google Translate link).

An Arduino Nano is the heart of the build, paired with a shield that lets it run a number of servo motors. The servos, one per key, are each assembled into a 3D-printed bracket with a cam-driven rod assembly. When the servo turns, the cam turns, and pushes down a rod that presses the piano key.

The build is limited in the sense that you can only play as many keys as you have servo channels, but nonetheless, it does the job. With eight servos, it’s able to play a decent rendition of Ode to Joy at a steady tempo, and that’s an excellent start.

We’ve featured some great mechanized instruments before, too. Video after the break.

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Radio Emissions Over Sunspots Challenge Models Of Stellar Magnetism

December 1, 2023 by 1 Comment

Sustained radio emissions originating from high over a sunspot are getting researchers thinking in new directions. Unlike solar radio bursts — which typically last only minutes or hours — these have persisted for over a week. They resemble auroral radio emissions observed in planetary magnetospheres and some stars, but seeing them from about 40,000 km above a sunspot is something new. They don’t seem tied to solar flare activity, either.

The signals are thought to be the result of electron cyclotron maser (ECM) emissions, which involves how electrons act in converging geometries of magnetic fields. These prolonged emissions challenge existing models and ideas about how solar and stellar magnetic processes unfold, and understanding it better could lead to a re-evaluation of existing astrophysical models. Perhaps even leading to new insights into the behavior of magnetic fields and energetic particles.

This phenomenon was observed from our very own sun, but it has implications for better understanding distant stellar bodies. Speaking of our sun, did you know it is currently in it’s 25th Solar Cycle? Check out that link for a reminder of the things the awesome power of our local star is actually capable of under the right circumstances.

Wine Is For Windows And Darling Is For MacOS

December 1, 2023 by 44 Comments

Wine has become a highly optimized and useful piece of software for those that live in Linux, but occasionally need to walk on the Windows side. In case you’d wondered, there’s a similar tool for when you need to run a MacOS program in your Linux environment. Enter Darling, the translation layer you’ve needed all along.

Just as Wine is not an emulator, nor is Darling. As a translation layer, it duplicates functions of the MacOS operating system that programs need to operate but within Linux. It’s fast, because it’s effectively running the MacOS software directly. Initially, Darling was mostly only capable of running MacOS apps at the console level. However, there is rudimentary support for running graphical applications that are based on the Cocoa framework.

Hilariously, if you’re into weird recursive situations, you can go deeper and run Darling within Windows Subsystem for Linux, itself running within Windows. Why? Well, you’re probably bored or just trying to for the sake of it. Regardless, we don’t judge. If you’ve got your own nifty translation or virtual machine hacks in the works, don’t hesitate to let us know!