[samsuksiri] frequently uses a laptop and has an external drive to store projects. The drive flops around on the end of its tether and gets in the way, so they repurposed their old iPod pouch and attached it to the laptop lid with double-sided tape. You can guess how that went — the weight of the drive caused the pocket to sag and eventually detach over time. Then [samsuksiri] remembered that they had LEGO DOTS patch stashed somewhere. It’s an 8×8 plate with adhesive on the back so you can build almost anywhere. Then the problem was this: how to attach LEGO to the drive itself? You’d think th ..read more

In the world of software development the term ‘optimization’ is generally reason for experienced developers to start feeling decidedly nervous, especially when a feature is marked as an ‘easy and free optimization’. The final keyword introduced in C++11 is one of such features. It promises a way to speed up object-oriented code by omitting the vtable call indirection by marking a class or member function as – unsurprisingly – final, meaning that it cannot be inherited from or overridden. Inspired by this promise, [Benjamin Summerton] figured that he’d run a range of benchmarks to see what per ..read more

Over the past century or so we’ve come up with some clever ways of manipulating photons to do all kinds of interesting things. From lighting to televisions and computer screens to communication, including radio and fiber-optics, there’s a lot that can be done with these wave-particles and a lot of overlap in their uses as well. That’s why you can take something like a fairly standard Wi-Fi antenna meant for fairly short-range communication and use it for some other interesting tasks like downloading satellite data. Weather satellites specifically use about the same frequency range as Wi-Fi, b ..read more

Lasers are pretty much magic — it’s all done with mirrors. Not every laser, of course, but in the 1980s, the most common lasers in commercial applications were probably the helium-neon laser, which used a couple of mirrors on the end of a chamber filled with gas and a high-voltage discharge to produce a wonderful red-orange beam. The trouble is, most of the optical power gets left in the tube, with only about 1% breaking free. Luckily, there are ways around this, as [Les Wright] demonstrates with this external passive cavity laser. The guts of the demo below come from [Les]’ earlier teardown ..read more

The average Hackaday reader hardly needs to be reminded of the incredible potential of the modern microcontroller. While the Arduino was certainly transformative when it hit the scene, those early 8-bit MCUs were nothing compared to what’s on the market now. Multiple cores with clock speeds measured in the hundreds of megahertz, several MB of flash storage, and of course integrated WiFi capability mean today’s chips are much closer to being fully-fledged computers than their predecessors. It’s not hard to see the impact this has had on the electronics hobby. In the early 2000s, getting your h ..read more

At the start of the 1970s the pocket calculator was the last word in personal electronics, and consumers in Europe looked eagerly towards Japan or the USA for a glimpse of new products. Meanwhile the European manufacturers, perhaps Philips in the Netherlands, or Olivetti in Italy, would no doubt have been putting their best engineers on to the task of delivering the first domestic European models. So who was first with a European-made calculator? Not the Dutch, the Italians, the Germans, or even the Brits, instead that honour went to the Yugoslavians. Digitron is a company located in Buje, in ..read more

When I was a kid we used to go to a place we just called “The Book Barn.” It was pretty descriptive, as it was just a barn filled with old books. It smelled pretty much like you’d expect a barn filled with old books to smell, and it was a fantastic place to browse — all of the charm of an old library with none of the organization. On one visit I found a stack of old magazines, including a couple of Popular Mechanics from the late 1940s. The cover art always looked like pulp science fiction, with a pipe-smoking father coming home from work to his suburban home in a flying car. But the issue th ..read more

If sharks with lasers on their heads weren’t bad enough, now China is working on submarines with lasers on their butts. At least, that’s what this report in the South China Morning Post claims, anyway. According to the report, two-megawatt lasers are directed through fiber-optic cables on the surface of the submarine, vaporizing seawater and creating super-cavitation bubbles, which reduce drag on the submarine. The report describes it as an “underwater fiber laser-induced plasma detonation wave propulsion” system and claims that the system could generate up to 70,000 newtons of thrust, more t ..read more

For decades now, we’ve been able to quickly and reliably interface musical instruments to computers. These tools have generally made making and recording music much easier, but they’ve also opened up a number of other out-of-the-box ideas we might not otherwise see or even think about. For example, [Joren] recently built a human interface device that lets him control a computer’s cursor using a flute instead of the traditional mouse. Rather than using a MIDI interface, [Joren] is using an RP2040 chip to listen to the flute, process the audio, and interpret that audio before finally sending re ..read more

What’s the simplest audio frequency oscillator you can imagine? There’s the 555, of course, and we can think of a few designs using just two transistors or even a few with just one. But how about an oscillator with no active components? Now there’s a neat trick. Replicating [Stelian]’s “simplest audio oscillator on the Internet” might take some doing on your part, since it relies on finding an old telephone. Like, really old — you’ll need one with the carbon granule cartridge in the handset, along with the speaker. Other than that, all you’ll need is a couple of 1.5-volt batteries, wiring eve ..read more