Sound Generation Board Makes The Tunes

[Mcjack123] has been getting into chiptunes lately and realized that his original interest started in 2018 when he used an Arduino to turn a TI-84 calculator into a sound machine. His latest iteration is a custom-designed soundboard and he takes us through the design and construction of it in a recent post.

The work models classic sound generators like the 2A03 or the Commodore 64 SID. You have a bunch of simple waveform generators along with filters and modulators to make various effects. These boards eventually gave way to FM synthesis devices like the Yamaha OPL2 and OPL3 chips. All of these cards accepted commands and generated audio on their own. More modern boards are more likely to simply convert digital data from the computer into audio.

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Hamvention 2022: The Reunion Begins Today

Calling all hams! Hamvention 2022 is underway and runs through the weekend at the Greene County Fair and Expo Center in Xenia, Ohio. It’s been three long years since Hamvention took place in person, and this year marks the 70th reunion of what has got to be the largest hamfest in the Midwest. If you’re in the area, you don’t want to miss it. You will need a ticket, though, and here are a few places you pick one up.

Indoors, you’ll find six buildings full of commercial vendors. But outside is where the real fun takes place — the flea market. What treasures will you uncover? There’s only one way to find out.

If you want to get into ham radio, there’s no place like a ham fest to kick off your journey. And if you’ve been poring over the ARRL handbook, you’re in luck, because they’re proctoring ham exams for free at the church across the street on Friday and Saturday.

Can’t make it out for whatever reason, but live close to the fairgrounds? Want to get in the mood on your way there? Tune to 1620AM within a five-ish mile radius to hear weather, traffic, and parking info, plus interviews and other assorted radio fun. If you live nowhere near Ohio, don’t despair — they are livestreaming it on YouTube.

[Note: the Hara Arena, pictured in our awesome Joe Kim artwork, is the old home of Hamvention, and was demolished in 2016. Better head off to the Greene County Fairgrounds instead.]

Square Cuts On Aluminum Extrusion, No Mill Required

If you’re looking for the perfect excuse to buy that big, beautiful Bridgeport mill, we’ve got some bad news: it’s not going to be making perfectly square end cuts on aluminum extrusion. Sadly, it’s much more cost-effective to build this DIY squaring jig, and search for your tool justification elsewhere.

There’s no doubting the utility of aluminum extrusion in both prototyping and production builds, nor that the versatile structural members often add a bit of class to projects. But without square cuts, any frames built from them can be seriously out of whack, leading to misery and frustration down the road. [Midwest Cyberpunk]’s mill-less solution uses a cheap Harbor Freight router as a spindle for a carbide endmill, riding on a laser-cut acrylic baseplate fitted with wheels that ride in the V-groove of — you guessed it — aluminum extrusions. A fence and clamping system holds the extrusion firmly, and once trammed in, the jig quickly and easily squares extrusions that have been rough cut with a miter saw, angle grinder, or even a hacksaw. Check out the video below for a peek at the build details.

We love the simplicity and utility of this jig, but can see a couple of areas for improvement. Adding some quick-throw toggle clamps would be a nice touch, as would extending the MDF bed and fence a bit for longer cuts. But even as it is, this tool gets the job done, and doesn’t break the bank like a mill purchase might. Still, if your heart is set on a mill, who are we to stand in the way?

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Hackaday Podcast 169: 3D Printing In Vase Mode, Measuring Nanovolts Through Mega DIY, And The Softest Pants Are Software Pants

Join Hackaday Editor-in-Chief Elliot Williams and Assignments Editor Kristina Panos as we take a tour of our top hacks from the past week. Elliot brought some fairly nerdy fare to the table this time, and Kristina pines for physical media as we discuss the demise of the iPod Touch, the last fruit-flavored mp3-playing soldier to fall.

But first, we talk about a why-didn’t-I-think-of-that 3D printing hack that leverages vase mode into something structural. We’ll take a look inside a see-through cyberdeck made from laptop parts, marvel over the minuscule voltages that can be picked up with a bit of meticulous meter design, and chew the fat about old rotary phones.

We also put in some overtime discussing a cheap fix for an expensive time card clock part, and rock out to a guitar that can use various things for its resonant cavity. Finally, Elliot questions the difference between software and firmware when it comes to hiding your dirty secrets, and Kristina bloviates about see-through electronics and music appreciation using whatever format you can afford.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments below!

Direct Download link

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Slow Races On A Pinewood Derby Track Built From Scratch

Pinewood derby racing is a popular pastime for scouting groups and many others besides. [Mr Coster] whipped up his own track with the assistance of some 3D printed parts, and used it to run a competition with a fun twist on the usual theme.

The track starts with a pair of MDF panels, on to which some strips are placed to act as guides for the racers. There’s also a release mechanism built with hinges and a pair of dowels that ensures both racers start the competition at exactly the same time. To give the track a nice transition from the downward slope to the horizontal, a series of curved transition pieces were designed in Fusion 360, 3D printed, and added to the course.

As for the competition, [Mr Coster] decided to eschew the usual focus on outright speed. Instead, students were charged with building the slowest possible car that could still complete the course. Just for the fun of it, though, the kids were then given one day to modify their slowest cars to compete in a more typical fastest-wins event. It gives the students a great lesson in optimizing for different performance parameters.

You might be old-school, though, and want to ruin the fun by taking it all way too seriously. Those competitors may wish to consider some of the advanced equipment we’ve featured before. Alternatively, you could run a no-holds-barred cheater’s version of the contest. Video after the break.

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This Week In Security: IPhone Unpowered, Python Unsandboxed, And Wizard Spider Unmasked

As conspiracy theories go, one of the more plausible is that a cell phone could be running malicious firmware on its baseband processor, and be listening and transmitting data even when powered off. Nowadays, this sort of behavior is called a feature, at least if your phone is made by Apple, with their Find My functionality. Even with the phone off, the Bluetooth chip runs happily in a low-power state, making these features work. The problem is that this chip doesn’t do signed firmware. All it takes is root-level access to the phone’s primary OS to load a potentially malicious firmware image to the Bluetooth chip.

Researchers at TU Darmstadt in Germany demonstrated the approach, writing up a great paper on their work (PDF). There are a few really interesting possibilities this research suggests. The simplest is hijacking Apple’s Find My system to track someone with a powered down phone. The greater danger is that this could be used to keep surveillance malware on a device even through power cycles. Devices tend to be secured reasonably well against attacks from the outside network, and hardly at all from attacks originating on the chips themselves. Unfortunately, since unsigned firmware is a hardware limitation, a security update can’t do much to mitigate this, other than the normal efforts to prevent attackers compromising the OS.
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Portable 3D Printer Gets Even Smaller, Faster, Better

How do you improve on a fast, capable 3D printer that sports an innovative design and is portable enough to fit in a printer spool box? Judging by what went into the Positron V3 portable printer, (video, embedded below) it takes a lot of hard work and an unwillingness to settle for compromise designs. Plus a few lucky breaks and some design wizardry.

When we first reported on [Kralyn]’s innovative “Positron” printer, its chief selling points were its portability and unique layout. With a fold-down Z-axis and a CoreXY-style drive in the base, plus an interesting 90° hot end and transparent heated build plate, the Positron managed to hit most of its design goals. But there’s always room for improvement, and Positron V3, shown in the video below, has made some pretty substantial leaps over that original concept.

The V3 design keeps the basic layout of the original, but greatly improves the usability and portability, while increasing performance and build volume. The heated borosilicate build plate is now held to the Z-axis drive with a much sturdier strut, and gets its juice through a high-temperature MagSafe connector. The X- and Y-axes are now driven by pancake steppers, which along with adding idler pulleys that are coaxial to the drive pulleys, make the CoreXY drive, and hence the printer’s base, much more compact. The printer is still much, much faster than most traditional gantry design, and print quality is on par with anything available commercially. And yes, it still fits into a standard 1-kg filament spool box when folded up.

We love this design, and the story of how the V3 came about and the intermediate V2 that didn’t make the cut is a fascinating case study in design. And as a bonus, [Kralyn] will open-source the V3 design, so you can build your own as soon as he releases the files.

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