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Does debounce delay the initial key press i.e.: [Button pressed]--[<5MS Debounce]--[Signal Proccessed]?

Ghilbi wrote:Does debounce delay the initial key press i.e.: [Button pressed]--[<5MS Debounce]--[Signal Proccessed]?

It shouldn't, but in many cases it does. It's also often over 5ms. It's kind of a crapshoot, mainly because it's not something the normal reviewers test for.

I see. I'm considering making a chart including all the possible factors outside of the users reaction time that will show input delay for various keyboard models and was curious. My plan right now is to contact manufacturers for the information, I'll include asking them to investigate if the debounce time is before or after. I 've inquired about two already and received some usable numbers from Steelseries about their Apex model.

I still need some pieces for the whole picture to come together, immediately two questions come to mind I'm not knowledgeable in: if all else is the same, would there be any difference between a key requiring 60g of actuation force and one of 30g? Would muscle memory slim the differences even further? Is there a formula that could approximate a plausible difference?

Lastly, what's the formula to compare different actuation distances?

Ghilbi wrote:I see. I'm considering making a chart including all the possible factors outside of the users reaction time that will show input delay for various keyboard models and was curious. My plan right now is to contact manufacturers for the information, I'll include asking them to investigate if the debounce time is before or after. I 've inquired about two already and received some usable numbers from Steelseries about their Apex model.

I still need some pieces for the whole picture to come together, immediately two questions come to mind I'm not knowledgeable in: if all else is the same, would there be any difference between a key requiring 60g of actuation force and one of 30g? Would muscle memory slim the differences even further? Is there a formula that could approximate a plausible difference?

Lastly, what's the formula to compare different actuation distances?

What did steelseries say about the apex model? I'd like to compare it to the WASD V1 and a cheapo rubber dome keyboard measured here: http://forums.blurbusters.com/viewtopic ... =10#p13473. As for actuation force and key travel, I assume lighter and shorter is going to be faster, but eventually you'll hit a tradeoff of hitting keys accidentally.

I remember I contacted Steelseries awhile ago asking for the debounce timings of their mice and they said something along the lines of "We don't test that", not surprising considering the 30ms debounce they put on the kinzu v2...

I'm really surprised if you got any information out of them.

Apex:
scan time 200 us
3mm throw
4ms debounce (not 100% sure that one is accurate)

As for measuring differing actuation force what do you think of this quote from an ocn user:

(60g vs 30g)
given constant acceleration and distance, time can be calculated as t = sqrt(2 * d / a).

In this case:

td = sqrt(2 * .002m / (30 * 9.81 ms-2)) - sqrt(2 * .002m / (60 * 9.81 ms-2)) = 1.08 ms

Ghilbi wrote:

Apex:
scan time 200 us
3mm throw
4ms debounce (not 100% sure that one is accurate)

As for measuring differing actuation force what do you think of this quote from an ocn user:

(60g vs 30g)
given constant acceleration and distance, time can be calculated as t = sqrt(2 * d / a).

In this case:

td = sqrt(2 * .002m / (30 * 9.81 ms-2)) - sqrt(2 * .002m / (60 * 9.81 ms-2)) = 1.08 ms

I think somebody pulled those acceleration figures out of thin air. Ideally you'd measure that with a high speed camera, and keyboards with various actuation forces and travel distance. I can press a single key about 10 times per second(Cherry MX brown). 2mm actuation point is about half the travel distance, so assuming the downstroke is half the cycle time, the first half of the downstroke would be about 25ms. A single press might be different, but it certainly isn't 23x faster.

Consistency might be another issue. A fast typist probably doesn't care too much about the absolute latency, but you want the delay to be very consistent. If one key takes 10ms longer to register than the next key, it would be pretty easy for the keyboard to register them in the wrong order. Particularly if that combination of keys is pressed by different fingers and it's typed frequently enough to build up muscle memory.

What do you say, a usable mean acceleration for my purposes?
source: http://journals.plos.org/plosone/articl ... ne.0020518

Based on that graph, about .5 g. Might be a bit higher for typing than playing piano, because with piano the goal isn't go faster no matter what.

Sparky wrote: I think somebody pulled those acceleration figures out of thin air. Ideally you'd measure that with a high speed camera, and keyboards with various actuation forces and travel distance. I can press a single key about 10 times per second(Cherry MX brown). 2mm actuation point is about half the travel distance, so assuming the downstroke is half the cycle time, the first half of the downstroke would be about 25ms. A single press might be different, but it certainly isn't 23x faster.

this estimate is good enough