> Thought idea: predict what key you are about to press next, and make the ones around it stiffer so you are less likely to press them by mistake.
If the bottom magnet were an electromagnet, then in fact one could make the keypress stiffer. As it stands, this project only changes the actuation point, but not the stiffness curve.
That said, I would love the feature that you mention. It could possibly introduce a new feedback concept to programming, similar to e.g. the shaker sticks that airline pilots are familiar with. Or, one could reduce the stiffness after a long day at work. Or increase the stiffness when the IDE detects e.g. that you're accessing a string position beyond bounds, or your SQL query is not parameterized but contains a concatenated user input.
The force for a cherry red switch is only around 50g. A brake, rather than direct electromagnetic force, could be used most of the time (see Playstation 5 controller [1]).
Recently, a few brands (Wooting, Razer, Steelseries, etc) have introduced keyboards with analogue-capable input (using either hall-effect, like the switch in the article, or optical sensors). This already allows the actuation to be set per-key in software, so your idea probably wouldn't even be that hard to implement with today's hardware! (although you may need a beefier microcontroller on the board)
On the "adjusting them as you type" front, the Wooting keyboards already support detecting a key retrigger even without a full release. They are monitoring key position and if you start to release and then push again they can make it trigger a new keypress.
I agree that having a software defined key-press resistance would be amazing. If you could manage that and then add in haptic feedback to simulate standard mechanical keyboard actuation clicks...
It actually makes sense to measure a linear scale of pressure instead of a single click, with a smart driver that knows if its a key you typically hit hard or gently eg d (index finger) vs z(little finger).
I believe it measures distance, so possibly speed as well, and force could be computed with knowledge of spring resistance. However, I don't think I saw anything in their material relating to these two terms.
I believe it's custom, because the mechanical part is actually just part of a sensor (it's just a magnet in a slider). The other part is the hall effect sensor which is soldered on the board. So, you can't drop these mechanical parts on to another board, they aren't self contained switches.
>Fans of Hall-effect mechanical switches note that they should last longer than traditional mechanical switches since they don't rely on metallic contact, which can result in degradation.
Has anyone ever typed so much on a keyboard that the switches wore out? Aren't they good for literally millions of actuations?
I had a keyboard fail on me because the spacebar ceased to trigger reliably. It was a cheap Chinese "let's shove a cheap laptop keyboard in an even cheaper plastic chassis to make it a small form factor USB keyboard". It took a couple of years of daily use but eventually the switch was kaput.
Also, arguably the most famous case of keyboards failing is Apple's infamous MacBook pro keyboard and it's propensity for phantom key presses.
> Has anyone ever typed so much on a keyboard that the switches wore out? Aren't they good for literally millions of actuations?
Yeah. Several. The keyboard might claim it's good for millions of actuations, but I write as well as program. At the end of the editing process, I have roughly 80,000 words entering the public sphere, a month. Excluding all rewriting. Imagine the abuse the spacebar has seen by the end of that.
It doesn't take much to scale that out to be murderous on cheaper keyboards, and serious wear and tear on the tougher ones.
A keyboard doesn't claim to be good for millions of actuations. You're referring to (a single) switch, which cost less than a dollar even for the most premium switches. They are easily replaced.
I don't know if 'worn out' is the correct term, but I've definitely typed my way through a few x220 keyboards. It just takes one dead key for the whole keyboard to be useless.
>Has anyone ever typed so much on a keyboard that the switches wore out?
Sure, somewhere in my collection of "stuff" there still rest two Cherry keyboards (mechanical, gold contacts) where certain keys stopped working reliably, the vowels a or e, IIRC.
They rest (instead of being disposed off) because I plan(ned) to open them sometime in the future to check if they malfunction due to corrosion, dirt or just mechanical wear.
Although the answer is literally yes, it is meaningfully no.
I have a keyboard that uses plate mounted Cherry MX reds, not lubed, pre re-tool (so the stems are a smidgen wobbly), and otherwise unremarkable. It is now 10 years old.
None of the switches have failed, and the most I had to do was replace the stock PBT keycaps with new ones because I had worn them down until they were smooth (very undesirable to type on). These keycaps seem to be better than the stock ones (a really cheap set of doubleshot-thick but dye sub colored I got for $30-some), and probably is at least another decade before I have to do it again.
I am probably past the million mark on important keys like WASD or space.
In the opposite direction: I had a keyboard once that I set aside for a couple of years and when I tried to use it again some of the keys didn't register reliably. It took a couple of days of use before everything worked smoothly.
I have a 5yo Cherry MX keyboard, and the rarely used keys (Scroll Lock, Pause, numpad) have a somewhat more defined feeling when they actuate than the most commonly used ones. The difference is subtle, but it's there.
Unfortunately a magnetic approach alone won't easily give a suitable force Vs displacement curve for a keyboard. The affirmative 'clunk' feeling as a key goes down isn't easy to replicate with fixed magnets
The key stems in a hall-effect key switch still use a spring. The magnet is not providing any (effective) movement resistance or levitation. It's there simply to provide the magnetic field for the sensor to measure.
Logitech of all manufacturers failed in this big time with their G1 gaming mouse. Press and hold can intermittently show as a released button, very much fun when dragging lines in Fusion 360 and then asking myself why the line is not continuous.
Millions of actuation might sound a lot, but you can reach those within a couple of months while gaming. Dirt ingress also can easily kill a switch. On my mice and trackballs I have to replace the micro-switches every 3-5 years, as they'll develop unintentional double-clicks, and that's without any fast paced gaming.
I've worn out at least two MS Ergonomic keyboards, I'm I'll diligently working on my third. I've worn out two Matias Pro Ergo keyboards, and another one will probably replace this MS board. I've worn out quite a few Cherry and Cherry-compatible switches, but I've been able to replace just the switches in those cases.
My current brown switch keyboard has lost all tactile bumps after 3+ years.
In the past, with starcraft apm spams, i definitely have experienced switches defects(dust collect over years, hard to repair) and keycaps defects on some of the more frequently used keys.
I had to replace a full set of Gateron switches because a growing number of my keys wouldn't input anything when pressed. They had come to feel mushy and didn't have the distinctive 'click' sound anymore.
I think it has more to do with how hard some people type, rather than how much; I've never worn out keyswitches but heard of plenty of others who did. Yet I've definitely typed more than several megabytes of text.
Ooh I want a set of these which replace the bottom neodymium with an electromagnet coil. Keeb circuit boards for swappable switches almost all have extra traces for RGB which can be repurposed.
Complete control over the full range of force? Yes please!
But let's be real: I actually want my keyboard to start typing out of nowhere like a freaky sorcerer's apprentice thing.
I can imagine this feels quite odd to type on. The force-distance curve between two magnets is very different from that of a spring --- the former is quadratic, the latter is linear.
Back around 2000 we had numerous force feedback joysticks, mice and steering wheels on the market, but only the steering wheels survived due to having a niche with sim racing. Joystick disappeared largely due to games switching to gamepads. Not quite sure why nobody ever tried to replicate the Logitech iFeel mice, that seems like a simple and cheap enough feature add into any mouse, especially these days with phone rumble motors being available for pennies. I quite liked the way the Nintendo Wii would give little haptics clicks when you moved the cursor over clickable UI elements, I'd imagine iFeel was similar, never tried it myself back then.
It needn't be a motor , it could be a solenoid - magnet combo configured to repel , with a microcontroller that varies the current position dependantly to immitate any profile one wants
The time-honoured quick and dirty approximation to that is to add a single solenoid to the keyboard and have it actuate every time a key actuates: https://youtu.be/1qw6ebySet0?t=305
It's not a mechanical keyboard switch, anyway. There's nothing to click. No moment when the force required decreases.
These keyboard enthusiasts should look into making replacement car dashboards. Something tactile to replace those awful touchscreens that keep people's eyes off the road.
The "mechanical keyboard" label is mostly arbitrary. Only somewhat reliable definition that matches with how it's widely used in context of keyboards that I can think of is "everything except, rubber dome, touchscreen and capacitive button keyboards (the ones without any moving parts, not the ones where keycap+spring moves one of capacitive surfaces)". Any attempts at defining it based on meaningful physical construction element or property will likely result in rubber dome keyboards classified as mechanical or some of the switches in "mechanical keyboards" as not mechanical.
According to your definition about point where force decreases -> half the mx keyboard switches are not mechanical because they are not clicky and have linear force curve without buckling point, but the rubber dome keyboards are "mechanical" because they have a point where dome buckles and force decreases.
If you look at the nature how the electrical contact or signal is made. Again rubber dome keyboard actually mechanically connect and disconnect the electrical contacts. But the few commercial "mechanical keyboards" using optical or magnetic switches which from the mechanical construction is almost identical to "real mechanical keyboards" would fall on the other side of split.
That said there is some use in classification of switches outside the context of keyboards based on whether they have any moving mechanical parts, or whether they contacts which get connected/disconnected during use and could increase resistance over time or spark in case of higher voltages and currents have their use in certain situations.
I use Cherry MX blacks, they also have no click (just like Silver, Red).
The advantage of auch a thing is that you can type them silent if you like. More silent than a typical laptop keyboard in fact. Being someone who does audio recording a lot this was the selling factor for me.
The lack of click is actually quite fine, I have no problems with it. You still have the spring you push down, so gaining a feeling for "when you hit it" is not that hard.
I assume you are referring to the part where article says that (hall effect sensor) "output being used to trigger MOSFETs". I have no idea where that came from, but in the schemeatics and code I looked at hall effect output was read using ADC like you would expect. Otherwise how else would you change the actuation point? You could digitise it by comparing it against adjustment pot with a discrete comparator IC, but that seems like 80% of hassle with 20% of functionality. Sample keypad in the linked repository doesn't do that. Either I am looking at different repository or Arstechnica writer blindly copied from the hackaday article, and hackaday writer was half asleep while reading schematic so wrote complete nonsense.
For a macro pad, maybe. For a full-sized keyboard, that would be a lot of ADC channels. Looking at Digikey, ADC chips seem to be about $0.50 per input in bulk, and that would add a lot of BOM cost to the keyboard.
You might be able to do better if you instead feed the Hall output into a sample-and-hold filter constructed out of a much cheaper op-amp. I suspect that would be an interesting engineering challenge.
Very interesting! A few months ago I was toying with the idea of using a permanent magnet in the stem and permanent/electromagnet at the bottom for adjustable weight / position sensing.
While it works in theory, in practice the feeling of magnet-on-magnet force curve feels really unnatural for typing (since it's not linear like most springs). Maybe some combination of both approaches would work better in my case.
Thought idea: predict what key you are about to press next, and make the ones around it stiffer so you are less likely to press them by mistake.