Exploring Different Keyboard Sensing Technologies

https://www.lttlabs.com/articles/2026/01/27/exploring-different-keyboard-sensing-technologies

by viraptor • 6 months ago

74 49 6 months ago

eknkc• 6 months ago

Is the mechanical keyboard craze still going on?

At some point everyone was talking about / showing off their mech keyboard in developer scene. I don’t think I’ve seen much in recent years.

I myself went deep into that for a while. Got a couple of keyboards and now I have two Apple Magic Keyboards. Don’t even know where I stashed my mechanicals.

bayindirh2• 6 months ago

The foam has disappeared, but the enthusiasts are going on. While it's not a craze, I believe mechanical keyboard is still superior for longer writing sessions (Apple's and Logitech's scissor switch keyboards are pretty good, too).

Gamers are moving to hall effect switches because of the things they enable, but from what I have seen, some people are still building their keyboards, and people still use mechanical keyboards.

I'd love to continue use mine, too, but they are bit too noisy for my office, and I don't continue computers at home as much, anymore.

Another chilling effect is caused by the tariffs, because people can't get their keyboards or parts as easily anymore. I got mine from Kickstarter directly, but it's impossible for me now.

toyg2• 6 months ago

Another chilling effect is caused by the tariffs

Maybe that's why prices in Europe seem to have gone down significantly. It used to be very expensive to get anything over here (UK), but now we're almost spoilt for choice.

arcologies19853• 6 months ago

Various patents expired and now you can get excellent typing keyboards from China for $30-50. Basically everyone I know who types for a living has one.

Gamers have moved on to analog keyboards which are controversial because some of their features straddle the line into cheats. e.g. with an analog keyboards you can negate all inertia in Counter-Strike or do speed tricks in Trackmania not otherwise easily accessible to keyboard players.

FuturisticLover• 6 months ago

In India, many brands are now offering low-cost mechanical keyboards. They were costly earlier but one can find super amazing one with 50% less cost now.

reedlaw3• 6 months ago

Could you give examples of excellent typing keyboards from China for $30-50? Every mechanical keyboard I've owned eventually suffered from key chatter or inconsistent actuation.

exitb• 6 months ago

Mechanical keyboard is still a sensible choice. With the advent of cheap 3D printing and custom PCBs, there's now also a lively DIY community, especially for odd/split layouts. I don't think it's a craze. It's just a hobby.

petepete• 6 months ago

It's still a craze but the people who want a nice keyboard to use daily found theirs and drifted away from the novelty/modding, I think.

I've used a HHKB Pro 2 since 2010 and it's still going strong. I have a replacement ready if/when it dies, but other than a shiny space bar it looks and feels like new.

Findecanor2• 6 months ago

They have become mainstream, so they are not special any more.

Even keyboards with what used to be enthusiast features, such as aluminium case, double-shot PBT keycaps, switch foam, plate foam, flex cuts, hot-swap, damping, etc. are available off-the-shelf at very reasonable prices now.

locknitpicker2• 6 months ago

Is the mechanical keyboard craze still going on?

It depends on your definition of "craze".

Mechanical keyboards are more popular than ever, and became mainstream to the point where nowadays they are just considered keyboards. Even Logitech sells whole product lines of mechanical keyboards, and even has specialized lines of mechanical keyboards.

Also, multiple companies sell ergonomic keyboards that fall within the "craze" classification. Even if they don't ship with noisy switches, they are still in line with what mechanical keyboards were known for.

Nowadays even the pure mechanical keyboards have non-mechanical switches. Optical, magnetic, hall effect, etc. they ship in the standard cherry MX form factor. But aren't mechanical.

A few years ago you had blue switches, red switches, brown switches... You could count the types of switches with your fingers. Nowadays the offer is so vast that you can't keep track. Some companies even sell sample kits with an array of different types of switches for customers to try out. That's a relatively new development.

And do I need to mention the massive inflow of mechanical keyboards on offer from cheap Chinese manufacturers? We're not looking at 400€ mechanical keyboards, but 20€ mechanical keyboards.

The truth of the matter is that in the past you barely had any choice in keyboards. You could choose brand and color, but it was always the same keyboard. Anyone who wanted something beyond this pattern was drawn to mechanical keyboarss. Not today.

So, knowing this, do you think it is a "craze"?

orbital-decay• 6 months ago

Utilitarian device to type on became an object of obsessive consumption, collection, customization, showing off, fashion (RGB lighting, forced mechanical over scissor distinction even though many people prefer the latter, etc). Yeah of course it's a craze, without scare quotes.

The same gear obsession happened to the gaming mice world, but it was much tamer by comparison.

d4rkp4ttern2• 6 months ago

I absolutely love my UHK [1] split mech keyboard that I ordered from Hungary several years ago. It’s the only one I stuck with after trying some other popular ones. Other than being split, the keyboard layout is standard so it’s easy to adapt to.

It probably helps me avoid RSI. I keep an apple trackpad between the two splits, so I never use a mouse. And a microphone in the middle as well, you can guess why. I clamshell my MacBook and almost always work on a monitor. Besides ergonomics, the biggest benefit is the on-board programmability; it lets me define custom layers and macros so I can trigger complex window management, app switching, and IDE navigation with simple key combos.

[1] https://uhk.io/

toyg2• 6 months ago

That's exactly how I used to work about 15 years ago, but I found that the Apple trackpad killed my wrists. These days I just have a regular mouse, and simply try to do as much as I can from the keyboard.

dddw• 6 months ago

It's less as hyped as during covid, but it's definitely still going strong. Its a hobby/collector thing. Cheaper than cars/watches/audio collecting.

akdor1154• 6 months ago

I want a keyboard switch with a weight on the end of a lever, typewriter or piano style. Or some other mechanism whereby the resistance would be constant or even reverse-linear-ish (from gravity and momentum), not linear (from a spring). But as far as I know no such thing exists. :(

Findecanor2• 6 months ago

There do exist switches with an almost flat force-curve, but those I've seen have been very light. For example 30g Topre.

aa-jv• 6 months ago

In the piano-/synth-keyboard world, this is accomplished by 'interlocked blades', consisting of two curved blades interconnected with notches for each key, allowing the curve of the pressure mechanism to be tuned according to the depth and scale of the notches.

Its always curious to me that this technology hasn't been adopted in the QWERTY keyboard field, although that may be due to patents .. as I understand it the piano keyboard manufacturers are very aggressive about protecting these patents, and its one of the reasons that all synth manufacturers get their keybed mechanisms from the same supplier (Fatar TP9S) .. though recent technology has moved on to use piezo-electric switches.

https://www.fatar.com/products/tp9s/

(Some other interesting details here: https://www.fatar.com/products/)

dcminter2• 6 months ago

I don't know how their switches worked, but the Wang 2200 terminals¹ that my father worked with had an interesting angle on tactile feedback; on each keypress a single chunky solenoid attached to it physically moved to give a satisfying "chunk" noise and vibration.

The idea presumably was to give solid mechanical feedback to professional typists used to the same from electromechanical typewriters throwing the type arm onto the platten.

Note this was late 70s/early 80s so I may be confusing/conflating it with other machines.

¹ https://en.wikipedia.org/wiki/Wang_2200#/media/File%3AWang22...

eggoa• 6 months ago

This guy sells new beam-spring keyboards with optional solenoids. https://www.modelfkeyboards.com

I have never seen one in person.

kps• 6 months ago

Those are buckling spring. Beam springs are older and different.

tristor• 6 months ago

I have one, the reproduction of the model F104, and it's great. However I no longer use it daily as I've since built a custom ergonomic mechanical keyboard to do the same duty. I did not opt for the solenoid. The F keyboards use buckling springs, just like the M keyboards, the beam-spring keyboards are of a different design.

SOTGO• 6 months ago

I can't say for sure about the Wang terminal keyboards, but what you're describing sounds a lot like a mechanism from some IBM Model B keyboards (usually called Beamsprings). I have an IBM 5251 keyboard that has a solenoid that hammers the side of the metal case whenever you type, and I've heard that it was added as users would have been used to typewriters and wanted to know for sure when they had registered a keypress

dcminter2• 6 months ago

So honestly I don't quite remember if I encountered this with the Wangs, or if I'm recalling my Dad telling me about it from his experiences.

If the latter then odds are that it was either a machine from Wang and in that case most likely the 2200, or otherwise it will have most probably been equipment associated with the Gamma 10 from De La Rue Bull, or possibly the Ferranti Pegasus - both of which I know he worked with.

Of course, he might have been telling me a third-party anecdote in which case it's possible the IBM Display Station was the machine in question.

That all said, last time I was discussing this with someone they mentioned that the 2200's terminal had a "solenoid" trace on its PCB so it's quite possible that this really was the relevant device. Last time I personally had hands on a live 2200 was about 1993 though, so I really can't be sure.

There's a chap in the Netherlands with a Wang 2200 museum - perhaps I should just write to him and ask :D

ortichic• 6 months ago

Does anyone know why alanlog optical switches never gained traction, but analog magnetic ones did? Sounds like optical ones should be cheaper to manufacture, with all the same benefits?

adrian_b2• 6 months ago

I believe that keys with optical switches are less reliable, being sensitive to things like sensor misalignment or dust.

I have not used any keyboard with optical switches, but several decades ago I have used keyboards with hall sensors, which had a superb quality and reliability, much better than anything that I have used later.

Sadly, I had to abandon the first keyboard that I have used with computers owned by me, which had Hall sensors, because it was not IBM PC compatible (its origin was in some DEC-compatible video terminal and I had used it with a Motorola MC68000 based PC, which I have replaced with a PC/AT clone, for which I had to use a compatible keyboard, of much lower quality).

Otherwise, I am certain that it would have remained perfectly functional until today, unlike the many keyboards that I had to replace since then, when too worn out.

wongarsu• 6 months ago

I have a hall-effect keyboard from Wooting, and they are indeed excellent. Very reliable, and setting the trigger point in software/firmware allows a number of interesting features like triggering different key codes depending on how far you've pressed the key down, enabling more rapid keypresses or using keys as analog input.

Their first keyboards actually used optical switches, and from everything I've heard were less reliable, and tracking precision was much worse than with the magnetic switches

riskable4• 6 months ago

Optical switches are great but they suffer from one problem that will annoy anyone that spent a ton of money on one: They don't last forever.

The reason is that the optical components are all plastic and that plastic degrades (yellows) over time due to exposure to UV light (which is all around us). They should last about 10 years in a normal office environment but I've heard reports that they're really only lasting about ~5 years.

Admittedly, five to ten years is probably fine. Just the gunk buildup in a normal keyboard is enough that most people would rather just buy a new keyboard than deal with cleaning it out. Even if the switches are hot-swappable! It really is a tedious thing that requires a lot of time and special tools (to do it right). Some keyboards and switches can only be hot-swapped a few times before they start to become wobbly/loose anyway.

I designed my Void Switches (https://github.com/riskable/void_switch) because I was sick of replacing keyboards so often (my fingers are like salt-water-drenched hammers, apparently). I also wanted a keyboard that was super easy to clean! Check it out:

https://imgur.com/pqGf0se

Every few weeks I take the top of my keyboard off and clean it out in sink with soap and water (and a scrub brush made for dishes). Been typing on this AHEK-95 for just over three years now so I've probably washed it at least 50 times and it's still working great!

NOTE: This is NOT patented technology! Logitech, Wooting, and all other keyboard manufacturers: WTF are you even doing‽ Copy my design already! I'll even help you do it! Make a keyboard that lets end users 3D print replacement switches/parts and you'll OWN THE MARKET (until others hop on board). What are you waiting for‽

UltraSane• 6 months ago

The Svalboard uses magnetic keys similar to your void switches.

joebig• 6 months ago

Minor physics nitpick in the article "...and a gradually widening conductor lets the inductance increase proportionally with key travel instead of jumping abruptly as the metal traverses the field. As the key is pressed, more of the cone moves into the field produced by the coil, inducing eddy currents in the metal. Following Lenz’s law, those currents oppose the original field, which increases the coil’s effective inductance..."

L, the inductance, is reduced, not increased due to insertion of a conductor, unless the conductor is ferromagnetic. A non-ferromagnetic conductor will expel flux due to generated eddy currents, lowering flux-linkage, therefore L, assuming driving coil current is held at a steady rms magnitude.

donatj• 6 months ago

My general experience with Cherry style mechanical key switches is disappointment. In my almost 40 years of computing they are the only type of key switch that have consistently given me issue. I've owned at least five boards at this point with them, and they all eventually have issues.

They're like owning a sports car, you have to get used to opening them up and cleaning the contacts, desoldering switches, oiling stems. They're just too high maintenance.

I gave that life up when the P key stopped working on my WhiteFox mid outage and I had to frantically switch keyboards.

My daily driver for the last five years has been a rubber dome Sun Type 7. It has given me zero problems, no one complains about the noise, it's got that so ugly it's cool "retro chic" thing going even though I bought it new direct from Oracle.

I still have multiple IBM buckling spring boards from when I was a kid and none of them have ever given me an issue.

bayindirh2• 6 months ago

That's pretty interesting. My first mechanical keyboard (Logitech G710+ with genuine Cherry Brown switches) withstood daily bashing of 7+ years, and it still types like the first day. Considering I wrote a Ph.D. on that incl. code and manuscript, it has been used relatively heavily, mixed with some gaming.

I have two other 75% mechanical keyboards, but they are not used as much, and I can't give any feedback on their longevity, but high quality switches do endure from my experience.

On the other hand, I had quite a few top of the line Microsoft keyboards, which were built very well, but their stems wear down after some time, even though their membranes survive. They become a workout instead of being a work enabler, then they are given away.

AlbertDenny• 6 months ago

This was a fun read. Hall effect switches especially feel like they came out of nowhere in the last couple years, but seeing them broken down like this makes the hype make more sense.

adrian_b2• 6 months ago

Keyboards with Hall effect switches have been frequently used many decades ago, before personal computers became dominant.

They were typically used in the more expensive models of video terminals that were used together with minicomputers or mainframes.

Personal computers used cheaper keyboards, to minimize the cost, so after everybody switched to using PCs the more expensive but better keyboards with Hall effect sensors have disappeared.

The keys with Hall effect sensors contain a special analog integrated circuit instead of metallic contacts. The IC is packaged similarly with a transistor, having 4 or sometimes only 3 pins that are soldered on the keyboard PCB.

So to make this kind of keyboard, you need a vendor for such an integrated circuit. Semiconductor IC vendors do not make such ICs, unless there is a market big enough for them.

During the seventies and the eighties, most IC vendors had such ICs in their catalog, but when the market for expensive keyboards disappeared, the production of such ICs has also stopped.

This has made more difficult for anyone to start making such keyboards, instead of other kinds of keyboards, because they must bet on selling enough of them, to be able to convince an IC vendor to make a batch of such ICs.

I have not seen any modern keyboard with Hall effect sensors, so I do not know whether they really use the kind of sensors made for keyboards that have been used originally. Perhaps they repurpose Hall sensors made for brushless DC motors, which are easily available anywhere, but they might need some additional external components in comparison with the special keyboard sensors.

t23414321• 6 months ago

That's mostly copycats of Ben Heck approach from 2012 - some technical improvements, but like without understanding, further thinking about function - or imagination why someone needed it first, then what would be next. So all seems stuck for me, and not much than a bit a closer since then to what (and how) I want, starting from smoothly increasing the repeat rate with pressure for cursor keys or scrolling (but not to have few levels only to macro-simulate that, then OS's are used to not get such things right - High Resolution Scrolling https://www.youtube.com/watch?v=FSy9G6bNuKA 2024).

(* XBOX Controller Mods: Analog WASD Gaming Keyboard https://www.youtube.com/watch?v=gEwDImE0DU4 2012 *)

riskable4• 6 months ago

The only thing I don't like about this article is it didn't talk about the actuation tech. It basically only showed switches with springs. My Void Switch design doesn't have springs at all!

https://github.com/riskable/void_switch

I'm typing on my AHEK-95 right now which has 95 Void Switches and a custom hall effect PCB (and custom firmware). It also has two custom analog rotary encoders (which is just a ring of six magnets over two hall effect sensors; the firmware is what figures out what direction the ring moved).

I sent one of my AHEK-95 keyboards to Chyrosran22 (known for his brutal keyboard reviews) and he reviewed it:

https://youtu.be/iv6Rh8UNWlI?si=9xGNm4jIDLFzx80c

One other thing missing in the article: Hall Effect sensors are temperature sensitive! My AHEK-95 has a number of features in the firmware to work around this (constant re-calibration) but anyone with other Hall Effect keyboards might have experienced it: Some keys seem to stop responding reliably after a while (usually a week or two in winter). This is because the temperature changed (enough), causing sensor drift. The fix is to just reset the keyboard (<1 second) which forces a recalibration but it can be annoying (my father in law has a Wooting keyboard that suffers from this after a few weeks if there's big temperature fluctuations at his desk which is right next to an exterior door).

Anyone with a 3D printer should print my Void Switches! It's a teeny tiny amount of filament (use PETG for best results) and only requires some 4x2mm magnets. I uploaded a model to Printables that has all the parts in one 3mf file: https://www.printables.com/model/233699-void-switch-fidget

Aside: Last time I ordered 4x2mm magnets, I ordered six thousand from AliExpress. That was after my last order of five thousand that I blew through quite quickly :D. I highly recommend ordering them in bulk like this because they end up costing about a penny each and they're useful in so many 3D printed things.

TGower• 6 months ago

Just wanted to say thanks for sharing your work! Was a great reference when working on hall effect datahand style project.

BrittonR• 6 months ago

Thanks for sharing, I’ll print this out to try. What’s the license in the pcb and switches?

chess_buster• 6 months ago

We've printed your switches at my university, they feel really great. Now we need to build a full keyboard in order to try out the typing experience, when used inside a keyboard.

Do you think the PCB and typing assembly could be made curved, like the assembly of a Model F or M keyboard?

riskable4• 5 months ago

Yes, you can make PCBs that can flex a bit but for that you're much better off using Flex PCB and being clever about the frame.

skybrian• 6 months ago

I’m making my own switches for a musical instrument (the dimensions don’t work well for mechanical keyboard switches) and decided on capacitive sensing because it’s cheap on a per-switch basis. Making things with copper tape is annoying, though. Using the spring as the capacitive element sounds promising.

Has anyone else tried this?

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