Author: Dan Maloney

3283 Articles

Fail Of The Week: The Little Remote-Controlled Snowblower That Couldn’t

March 3, 2024 by 18 Comments

[Punxatawny Phil]’s prognostications aside, winter isn’t over up here in the Northern Hemisphere, and the snow keeps falling. If you’re sick of shoveling the driveway and the walk and you don’t have a kid handy to rope into the job, relax —  this rapidly assembled junkyard RC snowblower will do just as crappy a job while you stay nice and warm inside.

This build seemed to have a lot of potential at the start, based as it was on a second-hand track-drive snowblower, something that was presumably purpose-built for the job at hand. [Lucas] quickly got to work on it; he left the original gasoline engine to power the auger but took most of the transmission off so that each track could be driven separately with a wheelchair motor.  That seemed like a solid idea as far as steering goes, but the fact that he chose to drive the 24 volt motors with a single 12 volt deep-cycle battery worked against him out in the snow.

With a battery upgrade for better traction, the snowblower actually got around in the snow pretty well. [Lucas] also added some nice features, like a linear actuator to remotely engage the auger — a nice safety touch when kids and pets are around — and a motor to control the direction of the chute. Even these improvements weren’t enough, though; it worked insofar as it moved snow from where it was to where it wasn’t, but didn’t really move it very far. To the casual observer, it seems like there’s just not enough weight to the machine, allowing it to ride up over the snow rather than scraping the driveway clean. Check out the video below and see what you think.

Now, we’re not picking on [Lucas] here. Far from it — we enjoyed this build as much as some of his other stuff, like his scratch-built CO2 laser tube and his potty-mouthed approach to Kaizen tool organization. We still think this one has a lot of potential, and we’re glad he vowed to continue working on it for next winter.

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Hackaday Links: March 3, 2024

March 3, 2024 by 26 Comments

Who’d have thought that $30 doorbell cameras would end up being security liabilities? That’s the somewhat obvious conclusion reached by Consumer Reports after looking at some entry-level doorbell cameras available through the usual outfits and finding glaring security gaps which are totally not intentional in any way.

All these cameras appear to be the same basic hardware inside different enclosures, most supporting the same mobile app. Our favorite “exploit” for these cameras is the ability to put them into a pairing mode with the app, sometimes by pressing a public-facing button. Slightly more technically challenging would be accessing images from the app using the camera’s serial number, or finding file names being passed in plain text while sniffing network traffic. And that’s just the problems CR identified; who knows what else lurks under the covers? Some retailers have stopped offering these things, others have yet to, so buyer beware.

Speaking of our techno-dystopian surveillance state, if you’ve had it with the frustrations and expense of printers, has Hewlett-Packard got a deal for you. They want you to never own a printer again, preferring that you rent it from them instead. Their “All-In Plan” launched this week, which for $6.99 a month will set up up with an HP Envy inkjet printer, ink deliveries, and 24/7 tech support. It doesn’t appear that paper is included in the deal, so you’re on your own for that, but fear not — you won’t go through much since the entry-level plan only allows 20 prints per month. Plans scale up to 700 prints per month from an OfficeJet Pro for the low, low price of $36. The kicker, of course, is that your their printer has to be connected to the Internet, and HP can pretty much brick the thing anytime they want to. The terms of service also explicitly state that they’ll be sending your information to advertising partners, so that’ll be fun. This scheme hearkens back to the old pre-breakup days of AT&T, where you rented your phone from the phone company. That model made a lot more sense when the phone (probably) wasn’t listening in on everything you do. This just seems like asking for trouble.

“Enhance, enhance…” Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/Simeon Schmauß

It’s been a while since Ingenuity‘s final rough landing on Mars permanently grounded the overachieving helicopter, long enough that it’s time for the post-mortem analyses to begin. The first photographic evidence we had was a shadowgram from one of the helicopter’s navigational cameras, showing damage to at least one of the rotor tips, presumably from contact with the ground. Then we were treated to a long-distance shot from Ingenuity‘s rover buddy Perseverance, which trained its MASTCAM instruments on the crash zone and gave us a wide view of its lonely resting place.

Now, geovisual design student [Simeon Schmauβ] has taken long shots made with the rover’s SuperCam instrument and processed them into amazingly detailed closeups, which show just how extensive the damage really is. One rotor blade sheared clean off on contact, flying 15 meters before gouging a hole in the regolith. Another blade looks to be about half gone, while the remaining two blades show the damaged tips we’ve already seen. That the helicopter is still on its feet given the obvious violence of the crash is amazing, as well as an incredible piece of luck, since it means the craft’s solar panel is pointing in roughly the right direction to keep it powered up.

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Hackaday Podcast Episode 260: KiCad 8, Two Weather Stations, And Multiple I2Cs

March 1, 2024 by 1 Comment

It’s a leap year, so Elliot and Dan put the extra day to good use tracking down all the hottest hacks from the past week and dorking out about them. There’s big news in the KiCad community, and we talked about all the new features along with some old woes. Great minds think alike, apparently, since two different e-ink weather stations made the cut this week, as did a floating oscilloscope, an automated film-developing tank, and some DIY solar panels.

We talked about a hacker who figured out that water makes a pretty good solar storage medium, and it’s cheaper than lithium, another who knows that a crappy lathe is better than no lathe, and what every hacker should know about Ethernet. Is there a future for room-temperature superconductors? Maybe it just depends on how cold the room is.

 

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Big Chemistry: Hydrofluoric Acid

February 27, 2024 by 32 Comments

For all of the semiconductor industry’s legendary reputation for cleanliness, the actual processes that go into making chips use some of the nastiest stuff imaginable. Silicon oxide is comes from nothing but boring old sand, and once it’s turned into ultrapure crystals and sliced into wafers, it still doesn’t do much. Making it into working circuits requires dopants like phosphorous and boron to give the silicon the proper semiconductor properties. But even then, a doped wafer doesn’t do much until an insulating layer of silicon dioxide is added and the unwanted bits are etched away. That’s a tall order, though; silicon dioxide is notoriously tough stuff, largely unreactive and therefore resistant to most chemicals. Only one substance will do the job: hydrofluoric acid, or HFA.

HFA has a bad reputation, and deservedly so, notwithstanding its somewhat overwrought treatment by Hollywood. It’s corrosive to just about everything, it’s extremely toxic, and if enough of it gets on your skin it’ll kill you slowly and leave you in agony the entire time. But it’s also absolutely necessary to make everything from pharmaceuticals to cookware, and it takes some big chemistry to do it safely and cheaply.

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A Deep Dive Into A 1980s Radio Shack Computer Trainer

February 26, 2024 by 17 Comments

For those of us who remember Radio Shack as more than just an overpriced cell phone store, a lot of the nostalgia for the retailer boils down to the brands on offer. Remember the Realistic line of hi-fi and stereo gear? How about Archer brand tools and parts? Patrolman scanners, Micronta test instruments, and don’t forget those amazing Optimus speakers — all had a place in our development as electronics nerds.

But perhaps the most formative brand under the Radio Shack umbrella was Science Fair, with a line of kits and projects that were STEM before STEM was a thing. One product that came along a little too late for our development was the Science Fair Microcomputer Trainer, and judging by [Michael Wessel]’s deep dive into the kit, we really missed the boat. The trainer was similar to the earlier “100-in-1”-style breadboarding kits, with components laid out on a colorful cardboard surface and spring terminals connected to their leads, making it easy to build circuits using jumper wires. The star of the show in the microcomputer trainer was a Texas Instruments TMS1100, which was a pretty advanced chip with a 4-bit CPU with its own ROM and RAM as well as a bunch of IO lines. The trainer also sported a peppy little 400-kHz crystal oscillator clock, a bunch of LEDs, a seven-segment display, a speaker, and a rudimentary keyboard.

The first video below is a general introduction to the trainer and a look at some basic (not BASIC) programs. [Michael] also pulls out the oscilloscope to make some rough measurements of the speed of the TMS1100, which turns out to be doing only about 400 instructions per second. That’s not much, but in the second video we see that it was enough for him to nerd-snipe his collaborator [Jason] into coding up an 80-nibble Tower of Hanoi solver. It’s a little awkward to use, as the program runs in spurts between which the user needs to check memory locations to see which disc to move to which peg, but it works.

It looks like people are rediscovering the Microcomputer Trainer all of a sudden. It might be a good time to pick one up.

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Op-Amp Drag Race Turns Out Poorly For 741

February 23, 2024 by 32 Comments

When it was first introduced in 1968, Fairchild’s 741 op-amp made quite a splash. And with good reason; it packed a bunch of components into a compact package, and the applications for it were nearly limitless. The chip became hugely popular, to the point where “741” is almost synonymous with “op-amp” in the minds of many.

But should it be? Perhaps not, as [More Than Electronics] reveals with this head-to-head speed test that compares the 741 with its FET-input cousin, the TL081. The test setup is pretty simple, just a quick breadboard oscillator with component values selected to create a square wave at approximately 1-kHz, with oscilloscope probes on the output and across the 47-nF timing capacitor. The 741 was first up, and it was quickly apparent that the op-amp’s slew rate, or the rate of change of the output, wasn’t too great. Additionally, the peaks on the trace across the capacitor were noticeably blunted, indicating slow switching on the 741’s output stage. The TL081 fared quite a bit better in the same circuit, with slew rates of about 13 V/μS, or about 17 times better than the 741, and nice sharp transitions on the discharge trace.

As [How To Electronics] points out, comparing the 741 to the TL081 is almost apples to oranges. The 741 is a bipolar device, and comparing it to a device with JFET inputs is a little unfair. Still, it’s a good reminder that not all op-amps are created equal, and that just becuase two jelly bean parts are pin compatible doesn’t make them interchangeable. And extra caution is in order in a world where fake op-amps are thing, too.

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