the PTC fuse to blame for the fault described, on the ROG Ally board, with a wire soldered across the fuse

ROG Ally SD Card Slot Fix Shines Light On PTC Fuse Failure Modes

May 4, 2024 by 3 Comments

The Asus ROG Ally is a handheld that, to our pleasant surprise, has attracted a decently sized modding community. Recently, we’ve stumbled upon a Reddit post investigating a somewhat common failure mode of this handheld — the microSD card slot going out of order, where an inserted card fails to be recognized, pretty irritating to encounter. Now, it turns out, this is down to a certain model of PTC fuses being failure-prone.

It makes sense to fuse the SD card slot. The cards are dense pieces of technology that are subject to some wear and tear in daily use. As such, it’s not unheard of that a microSD card can short-circuit internally — heating up to the point of melting plastic and giving people severe burns. Given that such a card is typically connected to a beefy 3.3 V rail, any mass-manufactured device designer could want to put a fuse between the 3.3 V rail and the card. However, on some ROG Ally batches, a certain make of the fuse is used, that appears to be likely to develop faults: the fuse’s resistance increasing dramatically during the card’s normal operation, with the SD card being supplied subpar power as a result.

There’s a fair bit of investigating happening in the comment section, with people posting oscilloscope captures, using breakouts to tap the SD card, and figuring out the fuse part numbers for the affected models. As for Reddit’s solution, it’s short-circuiting the fuse with a piece of thin wire — we would probably source a suitable fuse and solder it on top of the faulty one.

This isn’t the first ROG Ally modification we’ve covered so far, and given the activity we’re seeing, it’s unlikely to be our last.

Here’s How That Disney 360° Treadmill Works

May 3, 2024 by 14 Comments

One thing going slightly viral lately is footage of Disney’s “HoloTile” infinite floor, an experimental sort of 360° treadmill developed by [Lanny Smoot]. But how exactly does it work? Details about that are less common, but [Marques Brownlee] got first-hand experience with HoloTile and has a video all about the details.

HoloTile is a walking surface that looks like it’s made up of blueish bumps or knobs of some kind. When one walks upon the surface, it constantly works to move its occupant back to the center.

Whenever one moves, the surface works to move the user back to the center.

Each of these bumps is in fact a disk that has the ability spin one way or another, and pivot in different directions. Each disk therefore becomes a sort of tilted wheel whose edge is in contact with whatever is on its surface. By exerting fine control over each of these actuators, the control system is able to create a conveyor-belt like effect in any arbitrary direction. This can be leveraged in several different ways, including acting as a sort of infinite virtual floor.

[Marques] found the system highly responsive and capable of faster movement that many would find comfortable. When walking on it, there is a feeling of one’s body moving in an unexpected direction, but that was something he found himself getting used to. He also found that it wasn’t exactly quiet, but we suppose one can’t have everything.

How this device works has a rugged sort of elegant brute force vibe to it that we find appealing. It is also quite different in principle from other motorized approaches to simulate the feeling of walking while keeping the user in one place.

The whole video is embedded just below the page break, but if you’d like to jump directly to [Marques] explaining and showing exactly how the device works, you can skip to the 2:22 mark.

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Google Removes RISC-V Support From Android

May 3, 2024 by 16 Comments

Last year the introduction of  RISC-V support to the Android-specific, Linux-derived Android Common Kernel (ACK) made it seem that before long Android devices might be using SoCs based around the RISC-V ISA, but it would seem that these hopes are now dashed. As reported by Android Authority, with a series of recently accepted patches this RISC-V support was stripped again from the ACK. While this doesn’t mean that Android cannot be made to work on RISC-V, any company interested would have to do all of the heavy lifting themselves, which might include Qualcomm with their recently announced RISC-V-based smartwatch Snapdragon SoC.

No reason was provided by Google for this change, and the official statement from Google to Android Authority says that Google is not ready to provide a single supported Android Generic Kernel Image (GKI), but that ‘Android will continue to support RISC-V’. This change however, removes RISC-V kernel support from the ACK, and since Google only certifies Android builds which ship with a GKI featuring an ACK, this effectively means that RISC-V is not supported at this point, and likely won’t be for the foreseeable future.

As discussed on Hacker News, a potential reason might be the very fragmentary nature of the RISC-V ISA, which makes a standard RISC-V kernel very complicated if you want to support more than a (barebones) profile. This is also supported by a RISC-V mailing list thread, where ‘expensive maintenance’ is mentioned for why Google doesn’t want to support RISC-V.

A Vernier Take On A 3D Printer Extruder Indicator

May 3, 2024 by 5 Comments

A common way to visualize that a 3D printer’s extruder motor — which feeds the filament into the hot end — is moving is to attach a small indicator to the exposed end of the motor’s shaft. As the shaft turns, so does the attached indicator.

Small movements of the motor are therefore turned into larger movements of something else. So far, so simple. But what about visualizing very small extrusions, such as those tiny ones made during ironing?

[Jack]’s solution is a Vernier indicator for the extruder. Even the smallest movements of the extruder motor’s shaft are made clearly visible by such a device, as shown in the header image above. Vernier scales are more commonly found on measurement tools, and the concept is somewhat loosely borrowed here.

The usual way these lightweight indicators are attached is with a small magnet, and you can read all about them and see examples here.

This new design is basically the same, it simply has a background in a contrasting color added into the mix. [Jack]’s design is intended for the Bambu A1 printer, but the idea can be easily adapted. Give it a look if you find yourself yearning for a bit more visibility in your extruder movements.

A DIY coffee roaster with part callouts.

Follow The Red Ball Wobble Disk Roaster To Coffee Excellence

May 3, 2024 by 6 Comments

If you’ve never considered roasting your own coffee at home, you may be surprised to learn that it can be done in a few minutes with a regular popcorn popper and not much else. After all, you only really need two things to roast coffee: heat, and constant agitation to distribute that heat evenly. While the popcorn popper provides both, it’s easy to end up with semi-uneven roasts, probably because the beans are mostly just spinning around and not being tossed as well as they could be. Eventually, one might want a more advanced machine, and that’s where something like [Larry Cotton]’s latest wobble disk roaster can step in.

For starters, this machine roasts more beans than the average popcorn popper in a single throw — the maximum is 350g, or just over three-quarters of a full pound, which is way more than the average popcorn machine will hold. It essentially consists of a heat gun pointed upwards at a sieve full of green coffee beans that are being constantly pushed around by a motorized wobbling disk. As the heat blows, the large metal disk does figure eights through the beans, keeping the heat nice and even. So where does the red ball come in? It’s at the bottom, keeping the flying bean skins (chaff) from entering the heat gun’s fan motor.

Toward the end of the short video after the break, you’ll see a diagram showing all the parts of this roaster. If that’s not enough for you, here’s a build guide for a previous wobble disk roaster (PDF) that should be quite helpful in building either version.

If you want to see some of Larry’s previous machines, we’ve got ’em. And then you can let Hackaday Editor-in-Chief [Elliot Williams] tell you all about roasting at home.

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Plasma Cutter Gets CNC Treatment At Low Cost

May 3, 2024 by 8 Comments

[Daniel] has been metalworking on a budget for a while now. Originally doing things like plasma cutting on old bricks, he used his original plasma cutter to make an appropriate plasma cutting table complete with a water bath which we presume was not only safer but better for his back. Since then he’s stepped up a little more with what might be the lowest-cost CNC plasma cutter that can reliably be put together.

The CNC machine uses a handheld plasma cutting torch as its base, which uses a blowback start mechanism making it usable in an automated CNC setup without interfering with the control electronics. This is a common issue with other types of plasma cutters not originally meant for CNC. The torch head only needs slight modifications to fit in a 3D printed housing designed for the CNC machine which involves little more than slightly changing the angle of the incoming copper tubing and wire and changing the location of the trigger.

With those modifications done, the tool head is ready to be mounted to the CNC machine. [Daniel] has put together a bill of materials for building the entire project for less than $400, which includes the sub-$200 plasma cutter. It’s an impressive bit of sleuthing to get the price down this low, but if you’re still using your plasma cutter by hand on bricks in the yard like [Daniel] used to do make sure to check out that DIY plasma cutting table he built a few years ago too.

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My Space

May 3, 2024 by 23 Comments

If I could name one thing which has been the most transformative for our community over the last couple of decades, it would have to be the proliferation of hackerspaces. Ostensibly a place which provides access to tools and machinery, these organisations have become so much more. They bring together like-minded people, and from such a meeting of minds have come a plethora of high quality projects, events, and other good things.

Just What Is A Hackerspace?

A workshop with benches that have small vehickes in various stages of construction on them.
A Hacky Racer takes shape in the MK Makerspace workshop

Hackerspaces loosely come in many forms, from co-working spaces or libraries who have invested in a 3D printer and imagine themselves to be a hackerspace, through to anarchist collectives in abandoned warehouses who support their city’s alternative communities with technology. For me, hackerspaces must be community organisations rather than for-profit ones, so for the purposes of this article I’m not referring to closely-allied commercial spaces such as FabLabs.

So a good hackerspace for me is a group of tech enthusiasts who’ve come together, probably formed a non-profit association, and rented a dilapidated basement or industrial unit somewhere. The tools and machines inside aren’t shiny and new but they mostly work, and round that fridge stocked with Club-Mate you’ll find a community of friends, people who don’t think it’s odd to always want to know how things work. In a good hackerspace you’ll have found your place, and you can be much more than you would have been alone.

I visit plenty of hackerspaces across Europe as I wander the continent on an Interrail pass. I’m a member of three of them at the moment, though my main home in the UK is at Milton Keynes Makerspace. I’ve sat on recycled sofas drinking caffeinated beverages in more cities than I can count, and along the way I’ve seen close-up the many different ways a hackerspace can be run. I’ve seen spaces falling apart at the seams, I’ve seen ones a little too regimented for my taste, and others with too much of an emphasis on radical ideology, but mostly I’ve seen spaces that get it about right and I feel at home in. So perhaps it’s time to sit down and talk about what I think makes a good hackerspace. What is my space?

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