Hackaday Links Column Banner

Hackaday Links: October 29, 2023

“As California goes, so goes the nation.” That adage has been true on and off for the last 100 years or so, and it’s true again now that GM’s Cruise self-driving car unit has halted operations across the United States, just a couple of days after California’s DMV suspended its license to conduct driverless tests on state roadways. The nationwide shutdown of testing was undertaken voluntarily by the company and takes their sore beset self-driving taxi fleet off the road in Phoenix, Houston, Austin, Dallas, and Miami, in addition to the California ban, which seemed to be mainly happening in San Francisco. Cruise’s fleet has suffered all manner of indignities over the last few months, from vandalism to “coning” pranks to even being used as rolling hookup spots, and that’s not to mention all the trouble they caused by brigading to the same address or losing games of chicken with a semi and a firetruck. We’re not sure what to make of all this; despite our somewhat snarky commentary on the company’s woes, we take little pleasure in this development other than to the degree it probably increases roadway safety in the former test cities. We really do want to see self-driving cars succeed, at least for certain use cases, but it seems like this is a case of too much, too soon for the technology we currently have at our disposal.

Continue reading “Hackaday Links: October 29, 2023”

EcoEDA Integrates Your Junk Bin Into Your Designs

If you’re like us, there’s a creeping feeling that comes over you when you’re placing an order for parts for your latest project: Don’t I already have most of this stuff? With the well-stocked junk bins most of us sport and the stacks of defunct electronics that are almost always within arm’s length, chances are pretty good you do. And yet, we always seem to just click the button and place a new order anyway; it’s just easier.

But what if mining the treasure in your junk bin was easier? If you knew right at design time that you had something in your stash you could slot into your build, that would be something, right? That’s the idea behind ecoEDA, a Python-based KiCAD plugin by [Jasmine Lu], [Beza Desta], and [Joyce Passananti]. The tool integrates right into the schematic editor of KiCAD and makes suggestions for substitutions as you work. The substitutions are based on a custom library of components you have on hand, either from salvaged gear or from previous projects. The plug-in can make pin-for-pin substitutions, suggest replacements with similar specs but different pinouts, or even build up the equivalent of an integrated circuit from available discrete components. The video below gives an overview of the tool and how it integrates into the design workflow; there’s also a paper (PDF) with much more detail.

This seems like an absolutely fantastic idea. Granted, developing the library of parts inside all the stuff in a typical junk bin is likely the biggest barrier to entry for something like this, and may be too daunting for some of us. But there’s gold in all that junk, both literally and figuratively, and putting it to use instead of dumping it in a landfill just makes good financial and environmental sense. We’re already awash in e-waste, and anything we can do to make that even just a little bit better is probably worth a little extra effort. Continue reading “EcoEDA Integrates Your Junk Bin Into Your Designs”

“Cheap Yellow Display” Builds Community Through Hardware

For the most part, Hackaday is all about hardware hacking projects. Sometimes, though, the real hack in a project isn’t building hardware, but rather building a community around the hardware.

Case in point: [Brian Lough]’s latest project, which he dubs “CYD,” for the “cheap yellow display” that it’s based on; which is a lot easier to remember than its official designation, ESP32-2432S028R. Whatever you call it, this board is better than it sounds, with an ESP32 with WiFi, Bluetooth, a 320×480 resistive touch screen, and niceties like USB and an SD card socket — all on aforementioned yellow PCB. The good news is that you can get this thing for about $15 on Ali Express. The bad news is that, as is often the case with hardware from the Big Rock Candy Mountain, the only documentation available comes from a website we wouldn’t touch with a ten-foot pole.

To fix this problem, [Brian] started what he hopes will be a collaborative effort to build a knowledge base for the CYD, to encourage people to put these little gems to work. He has already kick-started that with a ton of quality documentation, including setup and configuration instructions, tips and gotchas, and some sample projects that put the CYD’s capabilities to the test. It’s all on GitHub and there’s already at least one pull request; hopefully that’ll grow once the word gets out.

Honestly, these look like fantastic little boards that are a heck of a bargain. We’re thinking about picking up a few of these while they last, and maybe even getting in on the action in this nascent community. And hats off to [Brian] for getting this effort going.

Continue reading ““Cheap Yellow Display” Builds Community Through Hardware”

Plasma Cutting And 3D Printing Team Up To Make Bending Thick Sheet Steel Easier

Metalworking has always been very much a “mixed method” art. Forging, welding, milling, grinding; anything to remove metal or push it around from one place to another is fair game when you’ve got to make something fast. Adding in fancy new tools like CNC plasma cutting and computer-aided drafting doesn’t change that much, although new methods often do call for a little improvisation.

Getting several methodologies to work and play well together is what [tonygoacher] learned all about while trying to fabricate some brackets for an electric trike for next year’s EMF Camp. The parts would have been perfect for fabrication in a press brake except for the 4 mm thickness of the plate steel, which was a little much for his smallish brake. To make the bending a little easier, [tony] made a partial-thickness groove across the plasma-cut blank, by using a reduced power setting on the cutter. This worked perfectly to guide the brake’s tooling, but [tony] ran into trouble with more complicated bends that would require grooves on both sides of the steel plate.

His solution was to 3D print a couple of sacrificial guide blocks to fit the bed of the press brake. Each guide had a ridge to match up with a guide groove, this allowed him to cut his partial grooves for both bends on the same side of the plate but still align it in the press brake. Yes, the blocks were destroyed in the process, but they only took a few minutes to print, so no big deal. And it’s true that the steel tore a little bit when the groove ended up on the outside radius of the bend, but that’s nothing a bead of weld can’t fix. Good enough for EMF is good enough, after all.

The brief video below shows the whole process, including [tony]’s interesting SCARA-like CNC plasma cutter, which we’re a little in love with now. This isn’t the first time we’ve seen 3D prints used as tools in metalworking, of course, but we picked up some great tips from this one. Continue reading “Plasma Cutting And 3D Printing Team Up To Make Bending Thick Sheet Steel Easier”

Retrotechtacular: Crash Testing Truck Attenuators, For Science

There are those among us who might bristle at something from the early 1980s qualifying for “Retrotechtacular” coverage, but it’s been more than 40 years since the California Department of Transportation’s truck-mounted attenuators crash testing efforts, so we guess it is what it is.

If you’re worried that you have no idea what a “truck-mounted attenuator” might be, relax — you’ve probably seen these devices attached to the backs of trucks in highway work zones. They generally look like large boxes attached to frames at the rear of the truck which are intended to soften the blow should a car somehow not see the giant orange truck covered with flashing lights and drive into the rear of it at highway speeds. Truck-mounted attenuators are common today, but back in 1982 when this film was produced, the idea was still novel enough to justify crash-testing potential designs.

Continue reading “Retrotechtacular: Crash Testing Truck Attenuators, For Science”

Simple Hack Lets Smartphone Take Resin Printer Time-Lapses

With how cheap they’re getting, everyone seems to be jumping on the resin printer bandwagon. They may not be able to fully replace your trusty old FDM printer, but for certain jobs, they just can’t be beaten. Sadly though, creating those smooth time-lapse videos of your prints isn’t quite as easy to do as it is on their filament-based counterparts.

Not as easy, perhaps, but not impossible. [Fraens] found a way to make time-lapses on any resin printer, and in a wonderfully hacky way. First, you need to find a smartphone, which shouldn’t be too hard, given how often we all tend to upgrade. [Fraens] recommends replacing the standard camera app on the phone with Open Camera, to prevent it from closing during the long intervals with nothing happening. The camera is triggered by any readily available Bluetooth dongle, which is connected via a simple transistor circuit to an Arduino output. To trigger the shutter, a light-dependent resistor (LDR) is connected to one of the microcontroller’s inputs. The LDR is placed inside the bed of the resin printer — an Anycubic Photon in this case — where light from the UV panel used to cross-link the resin can fall on it. A simple bit of Arduino code triggers the Bluetooth dongle at the right moment, capturing a series of stills which are later stitched together using DaVinci Resolve.

The short video below shows the results, which look pretty good to us. There are other ways to do this, of course, but we find the simplicity of this method pleasing.

Continue reading “Simple Hack Lets Smartphone Take Resin Printer Time-Lapses”

A Quick And Stealthy Mobile Slot Antenna From Copper Tape

[Ben Eadie (VE6SFX)] is at it again with the foil tape, and this time he’s whipped up a stealthy mobile sunroof antenna for the amateur radio operator with the on-the-go lifestyle.

You may recall [Ben]’s recent duck tape antenna for the 70-cm ham band, an ultra-lightweight design that lends itself to easy packing for portable operation. The conductors in that antenna were made from copper foil tape, a material that’s perfect for all sorts of specialized applications, like the slot antenna that he builds in the video below. In the ham world, slot antennas are most frequently seen cut into the main reflector of a direct satellite dish, often in hopes of avoiding the homeowner association’s antenna police. Even in the weird world of RF, it’s a strange beast because it relies on the absence of material in a large planar (or planar-ish) conductive surface.

Rather than grabbing an angle grinder to make a slot in the roof of his car, [Ben] created a “virtual” slot with copper tape on the inside of his car’s sunroof. His design called for a 39″ (0.99-m) slot, so he laid out a U-shaped slot to fit the window and outlined it with copper foil tape. His method was a little complex; he applied the copper tape to a transparent transfer film first, then stuck the whole thing to the underside of the glass in one go. It didn’t quite go as planned, but as he learned in the duck tape antenna, the copper tape makes it easy to repair mistakes. A BNC connector with pigtails is attached across the slot about 4″ (10 cm) up from the end of one of the short legs of the slot; yes, this looks like a dead short, but such are the oddities of radio.

Is it a great antenna? By the numbers on [Ben]’s NanoVNA, not really. But any antenna that gets you heard is a good antenna, and this one was more than capable in that regard. We’ll have to keep this in mind for impromptu antennas and for those times when secrecy is a good idea.

Continue reading “A Quick And Stealthy Mobile Slot Antenna From Copper Tape”