Know Audio: A Loudspeaker Primer

June 25, 2021 by Jenny List 27 Comments

As we’ve started out on our journey through the world of Hi-Fi audio from a strictly practical and engineering viewpoint without being misled by any audiophile woo, we’ve already taken a look at the most important component in any audio system: the listener’s ear. It’s time to move down the chain to the next link; the loudspeaker.

Sound is pressure waves in the air, and the purpose of a loudspeaker is to move the air to create those waves. There are a variety of “exotic” loudspeaker technologies including piezoelectric and electrostatic designs, here we’ll be considering the garden variety moving-coil speaker. It’s most usually used for the large bass or smaller mid-range drivers in a typical speaker system. Continue reading “Know Audio: A Loudspeaker Primer” →

Hackaday Podcast 124: Hard Drivin’ With Graphene, Fooled By Lasers, Etching With Poison Acid, And All The Linux Commands

June 25, 2021 by Dan Maloney 4 Comments

Hackaday editors Elliot Williams and Mike Szczys marvel at the dangerous projects on display this week, including glass etching with hydrofluoric acid and pumping 200,000 A into a 5,000 A fuse. A new board that turns the Raspberry Pi into an SDR shows off the power of the secondary memory interface (SMI) present in those Broadcom chips. We also discuss the potential for graphene in hard drives, and finish up with a teardown of a very early electronic metronome.

You know you want to read the show notes!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (55 MB or so.)

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Continue reading “Hackaday Podcast 124: Hard Drivin’ With Graphene, Fooled By Lasers, Etching With Poison Acid, And All The Linux Commands” →

This Week In Security: Schemeflood, Modern Wardialing, And More!

June 25, 2021 by Jonathan Bennett 17 Comments

There’s been yet another technique discovered to fingerprint users, and this one can even work in the Tor browser. Scheme flooding works by making calls to application URLs, something like steam://browsemedia. If your machine supports the requested custom URL, a pop-up is displayed, asking permission to launch the external application. That pop-up can be detected by JavaScript in the browser. Detect enough apps, and you can build a reasonable fingerprint of the system the test is run on. Unlike some previous fingerprinting techniques, this one isn’t browser dependent — it will theoretically give the same results for any browser. This means even the Tor browser, or any browser being used over the Tor network, can give your potentially unique set of installed programs away.

Now for the good news. The Chrome devs are already working on this issue, and in fact, Chrome on my Linux desktop didn’t respond to the probes in a useful way. Feel free to check out the demo, and see if the results are accurate. And as for Tor, you really should be running that on a dedicated system or in a VM if you really need to stay anonymous. And disable JavaScript if you don’t want the Internet to run code on your computer.
Continue reading “This Week In Security: Schemeflood, Modern Wardialing, And More!” →

ISS Gets Roll-Out Solar Panels In Post-Shuttle Fix

June 24, 2021 by Tom Nardi 18 Comments

Astronauts are currently installing the first of six new solar arrays on the International Space Station (ISS), in a bid to bolster the reduced power generation capability of the original panels which have now been in space for over twenty years. But without the Space Shuttle to haul them into orbit, developing direct replacements for the Stations iconic 34 meter (112 foot) solar “wings” simply wasn’t an option. So NASA has turned to next-generation solar arrays that roll out like a tape measure and are light and compact enough for the SpaceX Dragon to carry them into orbit.

Space Shuttle *Atlantis* carrying part of the ISS truss.

Considering how integral the Space Shuttle was to its assembly, it’s hardly a surprise that no major modules have been added to the ISS since the fleet of winged spacecraft was retired in 2011. The few small elements that have been installed, such as the new International Docking Adapters and the Nanoracks “Bishop” airlock, have had to fit into the rear unpressurized compartment of the Dragon capsule. While a considerable limitation, NASA had planned for this eventuality, with principle construction of the ISS always intended to conclude upon the retirement of the Shuttle.

But the International Space Station was never supposed to last as long as it has, and some components are starting to show their age. The original solar panels are now more than five years beyond their fifteen year service life, and while they’re still producing sufficient power to keep the Station running in its current configuration, their operational efficiency has dropped considerably with age. So in January NASA announced an ambitious timeline for performing upgrades the space agency believes are necessary to keep up with the ever-increasing energy demands of the orbiting laboratory.

Continue reading “ISS Gets Roll-Out Solar Panels In Post-Shuttle Fix” →

Teardown: Franz Crystal Metronome

June 22, 2021 by Tom Nardi 16 Comments

I wish I could tell you that there’s some complex decision tree at play when I select a piece of hardware to take apart for this series, but ultimately it boils down two just two factors: either the gadget was something I was personally interested in, or it was cheap. An ideal candidate would check both boxes, but that’s not always the case. This time around however, I can confidently say our subject doesn’t fall into either category.

Now don’t get me wrong, at first glance I found the Franz Crystal Metronome to be intriguing in its own way. With that vintage look, how could you not? But I’m about as far from a musician as one can get, so you’d hardly find a metronome on my wish list. As for the cost, a check on eBay seems to show there’s something of a following for these old school Franz models, with ones in good condition going for $50 to $80. Admittedly not breaking the bank, but still more than I’d like to pay for something that usually ends up as a pile of parts.

That being the case, why are you currently reading about it on Hackaday? Because it exploits something of a loophole in the selection process: it doesn’t work, and somebody gave it to me to try and figure out why. So without further ado let’s find out what literally makes a Franz Crystal Metronome tick, and see if we can’t get it doing so gain.

Continue reading “Teardown: Franz Crystal Metronome” →

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Chinese Typewriter

June 21, 2021 by Kristina Panos 12 Comments

As much as I’d like to devote an article to each and every bit of keyboard-related what-have-you that I come across in my travels through the intertubes, there just aren’t enough hours. And after all, this isn’t Clack-a-Day. To that end, I gained editorial approval to bring you a periodic round-up of news and other tidbits on the keyboard and keyboard accessories front, and here we are. So let’s get to it!

Continue reading “Keebin’ With Kristina: The One With The Chinese Typewriter” →

Microscopy Hack Chat With Zachary Tong

June 21, 2021 by Dan Maloney No comments

Join us on Wednesday, June 23 at noon Pacific for the Microscopy Hack Chat with Zachary Tong!

There was a time when electronics was very much a hobby that existed in the macroscopic world. Vacuum tubes, wire-wound resistors, and big capacitors were all mounted on terminal strips and mounted in a heavy chassis or enclosure, and interfacing with everything from components to tools was more an exercise in gross motor skills than fine. Even as we started to shrink components down to silicon chips, the packages we put them in were still large enough to handle and see easily. It’s only comparatively recently that everything has started to push the ludicrous end of the scale, with components and processes suitable only for microscopic manipulation, but that’s pretty much where we are now, and things are only likely to get smaller as time goes on.

The microscopic world is a fascinating one, and the tools and techniques to explore it are often complex. That doesn’t mean microscopy is out of the wheelhouse of the average hacker, though. Zachary Tong, proprietor of the delightfully eclectic Breaking Taps channel on YouTube, has been working in the microscopic realm a lot lately. We’ve featured his laser scanning confocal microscope recently, as well as his latest foray into atomic force microscopy. In the past he has also made DIY acrylic lenses, and he has even tried his hand at micromachining glass with lasers.

Zach is pretty comfortable working in and around the microscopic realm, and he’ll stop by the Hack Chat to share what he’s been up to down there. We’ll talk about all the cool stuff going on in Zach’s lab, and see what else he has in store for us.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, June 23 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.