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Hackaday Links: August 18, 2024

18 Agosto 2024 at 23:00
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They’re back! The San Francisco autonomous vehicle hijinks, that is, as Waymo’s fleet of driverless cars recently took up the fun new hobby of honking their horns in the wee hours of the morning. Meat-based neighbors of a Waymo parking lot in the South Market neighborhood took offense at the fleet of autonomous vehicles sounding off at 4:00 AM as they shuffled themselves around in the parking lot in a slow-motion ballet of undetermined purpose. The horn-honking is apparently by design, as the cars are programmed to tootle their horn trumpets melodiously if they detect another vehicle backing up into them. That’s understandable; we’ve tootled ourselves under these conditions, with vigor, even. But when the parking lot is full of cars that (presumably) can’t hear the honking and (also presumably) know where the other driverless vehicles are as well as their intent, what’s the point? Luckily, Waymo is on the case, as they issued a fix to keep the peace. Unfortunately, it sounds like the fix is just to geofence the lot and inhibit honking there, which seems like just a band-aid to us.

From the “Tech Doesn’t Make Everything Better” department, we’ve got news of a vulnerability in high-end racing bicycles that opens up a new vector for cheating. While our bike has been sitting sadly idle for the last twenty-odd years, apparently shifting technology has changed a lot, to the point where high-end derailleurs are no longer connected to handlebar-mounted shift lever by Bowden cables but now have servos that are linked to the shifters via Bluetooth. Anyone with more than a few minutes of experience with Bluetooth accessories and their default “123456” passwords can see where this is going. While there are no specific instances of cheating detailed in the story, one can imagine the hilarity to be had with a Flipper Zero while sitting on the side of a road at a course upgrade. To be sure, there are other ways to cheat, but we’re not sure we see the advantages of wireless shifting that offset the risks in this case.

Only 94 percent? A recent study claims to have quantified business spreadsheet errors, finding that 94% have critical problems. They came to this conclusion by mining literature from journal articles dating back to 1987, but rather than looking for papers with associated spreadsheets and analyzing them for errors, they looked for papers that discussed spreadsheet quality assurance. So this is sort of a meta-study, which makes us doubt the 94% finding. Still, we’d say it’s a safe bet that there are a lot of spreadsheets out there with critical errors, and that spreadsheet abuse is pretty rampant overall.

They say that if you’re not looking for your next job, you’re just waiting to get fired. That’s pretty much a tautology since there are only two — OK, three — ways out of any job, but it’s still good to always be looking for your next opportunity. So you might want to check out eejobboard, which allows you to do a parametric job search in the electrical engineering space. Pretty cool stuff.

And finally, we don’t have any information on this other than what you see in the video, but we’d love to learn more about these hardware FFTs. The video shows two implementations, one using a Zync 7020 FPGA, and one that uses over a thousand 74HC-series chips to do the same thing. If anyone out there knows the OP on this one, we’d love to get in touch.

Autonomous Boat Plots Lake Beds

15 Agosto 2024 at 05:00

Although the types of drones currently dominating headlines tend to be airborne, whether it’s hobbyist quadcopters, autonomous delivery vehicles, or military craft, autonomous vehicles can take nearly any transportation method we can think of. [Clay Builds] has been hard at work on his drone which is actually an autonomous boat, which he uses to map the underwater topography of various lakes. In this video he takes us through the design and build process of this particular vehicle and then demonstrates it in action.

The boat itself takes inspiration from sailing catamarans, which have two hulls of equal size connected above the waterline, allowing for more stability and less drag than a standard single-hulled boat. This is [Clay]’s second autonomous boat, essentially a larger, more powerful version of one we featured before. Like the previous version, the hulls are connected with a solar panel and its support structure, which also provides the boat with electrical power and charges lithium-iron phosphate batteries in the hull. Steering is handled by two rudders with one on each hull, but it also employs differential steering for situations where more precise turning is required. The boat carries a sonar-type device for measuring the water depth, which is housed in a more hydrodynamic 3d-printed enclosure to reduce its drag in the water, and it can follow a waypoint mission using a combination of GPS and compass readings.

Like any project of this sort, there was a lot of testing and design iteration that had to go into this build before it was truly seaworthy. The original steering mechanism was the weak point, with the initial design based on a belt connecting the two rudders that would occasionally skip. But after a bit of testing and ironing out these kinks, the solar boat is on its way to measure the water’s depths. The project’s code as well as some of the data can be found on the project’s GitHub page, and if you’re looking for something more human-sized take a look at this solar-powered kayak instead.

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