Handheld Oscilloscope Meter Reviewed

We live in a time where there’s virtually no excuse not to have some kind of oscilloscope. As [IMSAI Guy] shows in a recent video, for what you might expect to pay for a decent meter, you can now get one that includes a scope. There are several options out there but it is hard to know how much to spend to get the best possible product. The Zoyi ZT-702S that he looks at costs under $80. But is it worth it?

Scopes that connect to your PC are often very inexpensive. You can also find little toy scopes that use a microcontroller and a little LCD screen. Even though the specs on these are usually appalling, they will still let you visualize what’s happening in a circuit. Sure, you want an expensive bench scope with lots of channels sometimes, but often, you just need to see a signal in broad strokes. Having a scope and a meter together is very handy.

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FLOSS Weekly Episode 796: Homebrew, I’m More Of A Whopper Guy

This week Jonathan Bennett and David Ruggles chat with John Britton and Mike McQuaid about Homebrew! That’s the missing package manager for macOS; and Workbrew, the commercial offering built on top of it. We cover lots of territory, like why the naming scheme sounds like it was conceived during a pub visit, how Workbrew helps businesses actually use Homebrew, and why you might even want to run Homebrew on a Linux machine!

Continue reading “FLOSS Weekly Episode 796: Homebrew, I’m More Of A Whopper Guy”

Hacker Tactic: Pimp Your Probes

Is your multimeter one of your trusty friends when building up boards, repairing broken gadgets, and reverse-engineering proprietary ones? Is it accompanied by a logic analyzer or an oscilloscope at times?

Having a proper probing setup is crucial for many a task, and the standard multimeter probes just won’t do. As a PCB is slipping under your grip as you’re trying to hold the standard multimeter probes on two points at once, inevitably you will ponder whether you could be doing things differently. Here’s an assortment of probing advice I have accumulated.

Beyond The Norm

There’s the standard advice – keep your board attached firmly to a desk, we’ve seen gadgets like the Stickvise help us in this regard, and a regular lightweight benchtop vise does wonders. Same goes for using fancy needle probes that use gravity to press against testpoints – they might be expensive, but they are seriously cool, within limits, and you can even 3D-print them!

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A Really Low Level Guide To Doing Ethernet On An FPGA

With so much of our day-to-day networking done wirelessly these days, it can be easy to forget about Ethernet. But it’s a useful standard and can be a great way to add a reliable high-throughput network link to your projects. To that end, [Robert Feranec] and [Stacy Rieck] whipped up a tutorial on how to work with Ethernet on FPGAs. 

As [Robert] explains, “many people would like to transfer data from FPGA boards to somewhere else.” That basically sums up why you might be interested in doing this. The duo spend over an hour stepping through doing Ethernet at a very low level, without using pre-existing IP blocks to make it easier. The video explains the basic architecture right down to the physical pins on the device and what they do, all the way up to the logic blocks inside the device that do all the protocol work.

If you just want to get data off an embedded project, you can always pull in some existing libraries to do the job. But if you want to really understand Ethernet, this is a great place to start. There’s no better way to learn than doing it yourself. Files are on GitHub for the curious. Continue reading “A Really Low Level Guide To Doing Ethernet On An FPGA”

Laser Cutters: Where’s The Point?

It is funny how when you first start doing something, you have so many misconceptions that you have to discard. When you look back on it, it always seems like you should have known better. That was the case when I first got a low-end laser cutter. When you want to cut or engrave something, it has to be in just the right spot. It is like hanging a picture. You can get really close, but if it is off just a little bit, people will notice.

The big commercial units I’ve been around all had cameras that were in a fixed position and were calibrated. So the software didn’t show you a representation of the bed. It showed you the bed. The real bed plus whatever was on it. Getting things lined up was simply a matter of dragging everything around until it looked right on the screen.

Today, some cheap laser cutters have cameras, and you can probably add one to those that don’t. But you still don’t need it. My Ourtur Laser Master 3 has nothing fancy, and while I didn’t always tackle it the best way, my current method works well enough. In addition, I recently got a chance to try an XTool S1. It isn’t that cheap, but it doesn’t have a camera. Interestingly, though, there are two different ways of laying things out that also work. However, you can still do it the old-fashioned way, too. Continue reading “Laser Cutters: Where’s The Point?”

Wacky Science: Using Mayonnaise To Study Rayleigh-Taylor Instability

Sometimes a paper in a scientific journal pops up that makes you do a triple-take, case in point being a recent paper by [Aren Boyaci] and [Arindam Banerjee] in Physical Review E titled “Transition to plastic regime for Rayleigh-Taylor instability in soft solids”. The title doesn’t quite do their methodology justice — as the paper describes zipping a container filled with mayonnaise along a figure-eight track to look at the surface transitions. With the paper paywalled and no preprint available, we have to mostly rely the Lehigh University press releases pertaining to the original 2019 paper and this follow-up 2024 one.

Rayleigh-Taylor instability (RTI) is an instability of an interface between two fluids of different densities when the less dense fluid acts up on the more dense fluid. An example of this is water suspended above oil, as well as the expanding mushroom cloud during a explosion or eruption. It also plays a major role in plasma physics, especially as it pertains to nuclear fusion. In the case of inertial confinement fusion (ICF) the rapidly laser-heated pellet of deuterium-tritium fuel will expand, with the boundary interface with the expanding D-T fuel subject to RTI, negatively affecting the ignition efficiency and fusion rate. A simulation of this can be found in a January 2024 research paper by [Y. Y. Lei] et al.

As a fairly chaotic process, RTI is hard to simulate, making a physical model a more ideal research subject. Mayonnaise is definitely among the whackiest ideas here, with other researchers like [Samar Alqatari] et al. as published in Science Advances opting to use a Hele-Shaw cell with dyed glycerol-water mixtures for a less messy and mechanically convoluted experimental contraption.

What’s notable here is that the Lehigh University studies were funded by the Lawrence Livermore National Laboratory (LLNL), which explains the focus on ICF, as the National Ignition Facility (NIF) is based there.

This also makes the breathless hype about ‘mayo enabling fusion power’ somewhat silly, as ICF is even less likely to lead to net power production, far behind even Z-pinch fusion. That said, a better understanding of RTI is always welcome, even if one has to question the practical benefit of studying it in a container of mayonnaise.

Ryobi Battery Pack Gives Up Its Secrets Before Giving Up The Ghost

Remember when dead batteries were something you’d just toss in the trash? Those days are long gone, thankfully, and rechargeable battery packs have put powerful cordless tools in the palms of our hands. But when those battery packs go bad, replacing them becomes an expensive proposition. And that’s a great excuse to pop a pack open and see what’s happening inside.

The battery pack in question found its way to [Don]’s bench by blinking some error codes and refusing to charge. Popping it open, he found a surprisingly packed PCB on top of the lithium cells, presumably the battery management system judging by the part numbers on some of the chips. There are a lot of test points along with some tempting headers, including one that gave up some serial data when the battery’s test button was pressed. The data isn’t encrypted, but it is somewhat cryptic, and didn’t give [Don] much help. Moving on to the test points, [Don] was able to measure the voltage of each battery in the series string. He also identified test pads that disable individual cells, at least judging by the serial output, which could be diagnostically interesting.  [Don]’s reverse engineering work is now focused on the charge controller chip, which he’s looking at through its I2C port. He seems to have done quite a bit of work capturing output and trying to square it with the chip’s datasheet, but he’s having trouble decoding it.

This would be a great place for the Hackaday community to pitch in so he can perhaps get this battery unbricked. We have to admit feeling a wee bit responsible for this, since [Don] reports that it was our article on reverse engineering a cheap security camera that inspired him to dig into this, so we’d love to get him some help.