Hackaday Links: March 31, 2024

Battlelines are being drawn in Canada over the lowly Flipper Zero, a device seen by some as an existential threat to motor vehicle owners across the Great White North. The story started a month or so ago, when someone in the government floated the idea of banning devices that could be “used to steal vehicles by copying the wireless signals for remote keyless entry.” The Flipper Zero was singled out as an example of such a nefarious device, even though relatively few vehicles on the road today can be boosted using the simple replay attack that a Flipper is capable of, and the ones that are vulnerable to this attack aren’t all that desirable — apologies to the 1993 Camry, of course. With that threat hanging in the air, the folks over at Flipper Devices started a Change.org petition to educate people about the misperceptions surrounding the Flipper Zero’s capabilities, and to urge the Canadian government to reconsider their position on devices intended to explore the RF spectrum. That last bit is important, since transmit-capable SDR devices like the HackRF could fall afoul of a broad interpretation of the proposed ban; heck, even a receive-only SDR dongle might be construed as a restricted device. We’re generally not much for petitions, but this case might represent an exception. “First they came for the Flipper Zero, but I did nothing because I don’t have a Flipper Zero…”

Don’t you just hate it when the only way to get data from a device on your network is via the vendor’s cloud? We sure do, and so does Scott, a chap from Australia who went to amazing lengths to intercept data from his solar power system. It’s a long, drawn-out saga that appears to have lasted many months before he finally figured out how to set up what’s essentially a man-in-the-middle attack that lets him see data from his system before it gets shipped off to the vendor’s site. The great thing about his write-up is that he documents all the dead ends he encountered before hitting on the final answer. What impressed us most was the way that many of these side-quests yielded some kind of actionable information, even if it was just to give him a sense of what the developers were thinking of when they built the encryption for the IoT part of this. Spoiler alert: they weren’t very good at it. We just love stories about such reverse-engineering heroics; tip of the hat to Hash over at RECESSIM for featuring this story on his latest “Reverse Engineering News” segment.

Given their eye-watering budgets, you’d be forgiven the thought that every effect seen in Hollywood movies is accomplished with some kind of bespoke device that costs a ton of money. But sometimes it’s the simple hacks that get a production brought in on time and budget. A great example is this cordless drill camera shaker, which was spotted in a recent production about Formula E racing. The drill, which appears to be wearing Bosch livery, has an eccentric wooden disc chucked up in it. The drill rests up against the side of an Arri Super 35 cine camera and when the trigger is pressed, the wobbling disc recreates the vibration a race car driver endures. Ironically enough, the camera appears to be mounted on a Steadicam, a camera stabilizer intended to make smooth shots.

SMD assembly is easy, right? Just take your PCB, arrange all the extra boards into a jig, tape down your stencil, and smear the solder paste out with whatever squeegee-like tool you can find. But what (sometimes) works at home doesn’t always scale well, as evidenced by this “Everything you ever wanted to know about stencil printing but were afraid to ask” guide. It’s a PDF of a slide deck by Chrys Shea, who really gets down into the weeds on stencil printing. There are a ton of fascinating technical details that we had no idea about, like the degree to which the area ratio (the ratio of the stencil thickness to the area of a given aperture) affects the transfer efficiency, or how much solder paste gets stuck to the pad versus how much sticks to the stencil walls. There’s also stuff in there about nanocoating stencil walls, the properties of solder paste — turns out it’s a non-Newtonian fluid — the effects of board support on gasketing, and that “squircles” are better than squares. We’d love to have seen the presentation live, but the slide deck is still really useful. As is “The Analog,” which is where we found this gem — if you aren’t subscribed to it, you really should.

And finally, can you cook a hot dog using an AM radio tower? For certain values of cooking, yes. If this sounds to you like shenanigans the Geerling boys would be up to, you’re right, with the senior Geerling, a radio engineer, doing the actual cooking, and his son Jeff serving as sous chef. The hot dog was impaled on some grounded wire tines on the end of an insulated stick and held near an operating AM radio tower. That didn’t do much, but the show started once the hapless frank was pushed into contact with the tower. The raw power quickly vaporized the meat, while simultaneously acting as a receiver for the signal. If you ever thought touching a live radio tower would be a good idea, it’s not. Just ask the hot dog.

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