Review: Cherry G84-4100 Keyboard

December 12, 2025 by Jenny List 41 Comments

The choice of a good keyboard is something which consumes a lot of time for many Hackaday readers, judging by the number of custom input device projects which make it to these pages. I live by my keyboard as a writer, but I have to admit that I’ve never joined in on the special keyboard front; for me it’s been a peripheral rather than an obsession. But I’m hard on keyboards, I type enough that I wear them out. For the last five years my Hackaday articles have come via a USB Thinkpad keyboard complete with the little red stick pointing device, but its keys have started parting company with their switches so it’s time for a replacement.

I Don’t Want The Blackpool Illuminations

A picture of the Blackpool illuminations at night against a dark sky. — Is it a gamer’s keyboard, or the Blackpool seafront at night? I can’t tell any more. Mark S Jobling, Public domain.

For a non keyboard savant peering over the edge, this can be a confusing choice. There’s much obsessing about different types of mechanical switch, and for some reason I can’t quite fathom, an unreasonable number of LEDs.

I don’t want my keyboard to look like the Blackpool Illuminations (translation for Americans: Las Vegas strip), I just want to type on the damn thing. More to the point, many of these “special” keyboards carry prices out of proportion to their utility, and it’s hard to escape the feeling that like the thousand quid stereo the spotty kid puts in his Opel Corsa, you’re being asked to pay just for bragging rights.

Narrowing down my needs then, I don’t need any gimmicks, I just need a small footprint keyboard that’s mechanically robust enough to survive years of my bashing out Hackaday articles on it. I’m prepared to pay good money for that.

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Cheap 10x10cm Hotplate Punches Above Its Weight

December 10, 2025 by Arya Voronova 14 Comments

For less than $30 USD, you can get a 10×10 centimeter hotplate with 350 Watts of power. Sounds mighty fine to us, so surely there must be a catch? Maybe not, as [Stefan Nikolaj]’s review of this AliExpress hotplate details, it seems to be just fine enough.

At this price, you’d expect some shoddy electronics inside, or maybe outright fiery design decisions, in the vein of other reviews for similar cheap heat-producing tech that we’ve seen over the years. Nope – the control circuitry seems to be more than well-built for our standards, with isolation and separation where it matters, the input being fused away, and the chassis firmly earthed. [Stefan] highlights just two possible problem areas: a wire nut that could potentially be dodgy, and lack of a thermal fuse. Both can be remedied easily enough after you get one of these, and for the price, it’s a no-brainer. Apart from the review, there’s also general usage recommendations from [Stefan] in the end of the blog post.

While we’re happy to see folks designing their own PCB hotplates or modifying old waffle irons, the availability of cheap turn-key options like this means there’s less of a reason to go the DIY route. Now, if you’re in the market for even more build volume, you can get one of the classic reflow ovens, and maybe do a controller upgrade while you’re at it.

Target The Best AA, And Take No Flak

November 9, 2025 by Tyler August 68 Comments

In this era of cheap lithium pouch cells, it might seem mildly anachronistic to build AA batteries into a project. There are enough valid reasons to do so, however, and enough legacy hardware that still takes AAs, that it’s worth spending some time deciding which batteries to use. Luckily for us, [Lumencraft] over on YouTube has done the legwork in the video embedded below, and even produced a handy-dandy spreadsheet.

Each battery in the test underwent three separate tests. There was the “leave it in a flashlight ’til it dies” test for real-world usage, but also discharge curves logged at 250mA and 2A. The curves for each are embedded in the spreadsheet so you can see what to expect, along with the calculated capacity at each discharge rate. 2A seems like a fairly brutal load for AAs, but it’s great to see how these cells react to extremes. The spreadsheet also includes the cell’s cost to create a value ranking, which will be of great use to our readers in the USA, where it appears [Lumencraft] is buying batteries. The world market is likely to have the same batteries available, but prices may vary by region, so it’s worth double-checking.

In the video, [Lumencraft] also takes the time to explain the four battery types commonly found in AA format, and the strengths and weaknesses of each chemistry that might cause you to prefer one over another for specific use cases, rather than going by his value rankings. Unsurprisingly, there’s virtually no reason other than cost to go for alkaline batteries in 2025. However, lithium-ion batteries in AA form don’t really outperform NiMH enough to make the added cost worthwhile in all applications, which is why the overall “best battery” is a “PowerOwl” NiMH. Li-ion’s unspectacular performance is likely in part due to the inefficiencies introduced by a built-in buck converter and safety circuitry. On the other hand, some people might really appreciate that extra safety compared to bare 18650 cells.

The results here aren’t too dissimilar to what we saw earlier this year, but we really appreciate [Lumencraft] publishing his results as a spreadsheet for easy reference. The only caveat is that he’s taking manufacturers at their word as to how many cycles the batteries will last.

Oh, and just to be 100% clear — we are talking about double-A batteries, not Anti-Aircraft batteries. If anyone has an anti-aircraft battery hack (especially if that hack includes double-A batteries powering the AA batteries), please send in a tip.

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A Nuclear Physics Lab In Your Pocket

October 25, 2025 by Al Williams 17 Comments

If you want to work with radioactive material, a cheap Geiger counter isn’t really what you want. According to [Project 326], you need a gamma ray spectrometer. The video below reviews the Radiacode 110. The channel has reviewed other Radiacode products, and they haven’t always been pleased with them, apparently. Is the 110 better?

The little spectrometer uses a scintillation crystal and performs a spectrogram on the result. It has a large library of materials so, at least for radioactive materials, you can point it at something and tell what kind of material you are dealing with and how radioactive it is.

While the smartphone app seems well done, the Windows application left something to be desired. Even still, it was able to identify several isotopes. The device can even pick up some alpha emitters that don’t directly register. However, it can identify some materials by different decomposition products. Unlike some earlier models, this device is supposed to be highly sensitive and high-resolution.

To confirm this, [Project 326] built a lead shielding structure and read a reference sample. Crunching some numbers confirmed that the claimed performance was accurate. It could even read very low-energy sources, though there were some limitations. The ergonomics of the device could be better, apparently, but it does deliver on performance.

Do you need a gamma ray spectrometer? We don’t know, but we suspect if you do, you don’t need us to tell you.

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Fnirsi IPS3608: A Bench Power Supply With Serious Flaws

September 20, 2025 by Maya Posch 17 Comments

Fnirsi is one of those brands that seem to pop up more and more often, usually for portable oscilloscopes and kin. Their IPS3608 bench power supply is a bit of a departure from that, offering a mains-powered PSU that can deliver up to 36 VDC and 8 A in a fairly compact, metal enclosure. Recently [Joftec] purchased one of these units in order to review it and ended up finding a few worrying flaws in the process.

One of the claims made on the product page is that it is ‘much more intelligent than traditional power supplies’, which is quite something to start off with. The visual impression of this PSU is that it’s somewhat compromised already, with no earth point on the front next to the positive and negative banana plug points, along with a tilting screen that has trouble staying put. The USB-C and -A ports on the front support USB-PD 3.0 and a range of fast charge protocols

The ‘intelligence’ claim seems to come mostly from the rather extensive user interface, including a graphing function. Where things begin to fall apart is when the unit locks up during load testing presumably due to an overheating event. After hooking up an oscilloscope, the ripple at 1 VDC was determined to be about 200 mV peak-to-peak at 91 kHz. Ripple increased at higher voltages, belying the ’10 mV ultra-low ripple’ claim.

A quick teardown revealed the cause for the most egregious flaw of the unit struggling to maintain even 144 Watt output: a very undersized heatsink on the SMPS board. The retention issues with the tilting issue seemed to be due to a design choice that prevents the screen from rotating without breaking plastic. While this latter issue could be fixed, the buggy firmware and high ripple on the DC output make this €124 ‘285 Watt’ into a hard pass.

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Bambu Lab’s PLA Tough+ Filament: Mostly A Tough Sell

September 9, 2025 by Maya Posch 21 Comments

Beyond the simple world of basic PLA filaments there is a whole wild world of additives that can change this humble material for better or worse. The most common additives here are primarily to add color, but other additives seek to specifically improve certain properties of PLA. For example Bambu Lab’s new PLA Tough+ filament series that [Dr. Igor Gaspar] over at the My Tech Fun YouTube channel had over for reviewing purposes.

According to Bambu Lab’s claims for the filament, it’s supposed to have ‘up to’ double the layer adhesion strength as their basic PLA, while being much more robust when it comes to flexing and ‘taking a beating’. Yet as [Igor] goes through his battery of tests – comparing PLA Tough+ against the basic PLA – the supposedly tough filament is significantly worse in every count. That sad streak lasts until the impact tests, which is where we see a curious set of results – as shown above – as well as [Igor]’s new set of impact testing toys being put through their paces.

Of note is that although the Tough+ variants tested are consistently less brittle than their basic PLA counterparts, the Silver basic PLA variant makes an unexpectedly impressive showing. This is a good example of how color additives can have very positive impacts on a basic polymer like PLA, as well as a good indication that at least Bambu Lab’s Basic PLA in its Silver variant is basically better than Tough+ filaments. Not only does it not require higher printing temperatures, it also doesn’t produce more smelly VOCs, while being overall more robust.

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Why Cheap Digital Microscopes Are Pretty Terrible

August 3, 2025 by Maya Posch 41 Comments

The depth of field you get with a cheap Tomlov DM9 digital microscope. Pictured is the tip of a ballpoint. (Credit: Outdoors55, YouTube)

We have all seen those cheap digital microscopes, whether in USB format or with its own screen, all of them promising super-clear images of everything from butterfly wings to electronics at amazing magnification levels. In response to this, we have to paraphrase The Simpsons: in this Universe, we obey the laws of physics. This applies doubly so for image sensors and optics, which is where fundamental physics can only be dodged so far by heavy post-processing. In a recent video, the [Outdoors55] YouTube channel goes over these exact details, comparing a Tomlov DM9 digital microscope from Amazon to a quality macro lens on an APS-C format Sony Alpha a6400.

First of all, the magnification levels listed are effectively meaningless, as you are comparing a very tiny image sensor to something like an APS-C sensor, which itself is smaller than a full-frame sensor (i.e., 35 mm). As demonstrated in the video, the much larger sensor already gives you the ability to see many more details even before cranking the optical zoom levels up to something like 5 times, never mind the 1,500x claimed for the DM9.

On the optics side, the lack of significant depth of field is problematic. Although the workarounds suggested in the video work, such as focus stacking and diffusing the light projected onto the subject, it is essential to be aware of the limitations of these microscopes. That said, since we’re comparing a $150 digital microscope with a $1,500 Sony digital camera with macro lens, there’s some leeway here to say that the former will be ‘good enough’ for many tasks, but so might a simple jeweler’s loupe for even less.

There are some reasonable hobby-grade USB microscopes. There are also some hard-to-use toys.

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