[sdiy] A different kind of polyphonic aftertouch

Mike HEQX mike at heqx.com
Sun Dec 17 17:02:46 CET 2017

Yes it's the midi paradigm that I was thinking under.

That's the thing about midi. Some of it is based on the Piano, and 
that's a limited scope in terms of key action, and also very specific to 
hammer action. Ultimately a limiting factor in creating new instruments. 
maybe i have not seen the full spectrum of controllers though.

Roli did a good job with the Seaboard as a workaround solution. Even 
with HD midi are we really leaving the piano model and being more open? 
Not sure on that one.


On 12/17/2017 1:43 AM, rsdio at audiobanshee.com wrote:
> You don't even need two thresholds.
> Velocity is the difference between any two positions, provided that you know the time between the measurement of each position. Since most keyboard scanners run at a fixed polling rate, every scan could produce a velocity by comparing the old and new positions. Negative velocities would simply be release velocity.
> You still might want thresholds of a sort, depending upon whether you want the MIDI Velocity to reflect the first velocity measurement after the key leaves the top position, or the last velocity measure before the key hits the bottom position. It would be interesting to see how much they differ, and which corresponds more closely to the feel of the musician.
> If you break out of the MIDI paradigm, though, you could have a messaging protocol with continuous position and velocity updates.
> Brian
> On Dec 16, 2017, at 8:45 PM, Mike HEQX <mike at heqx.com> wrote:
>> This type of linear sensing can also sense velocity just like two switches do now in most keybeds, just by setting two thresholds. So you get the linear and switching at the same time and it's adjustable. Very useful.

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