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There are elegant ways for handling actuator/software mismatch for actuators with finite travel, like pots and faders.

Most schemes involve scaling the available fader travel to the "available" software travel.

Ex: Fader at 40%, software at 60%. Fader motion "up" between 40-100 moves software "up" between 60-100. Fader motion "down" between 40-0 moves software "down" between 60-0.

There are various other schemes, including multiple regimes and nonlinearity. Programmable synthesizers have dealt with this for many years. See pp13-14 of this manual for an example: https://www.davesmithinstruments.com/wp-content/uploads/2015...




What happens when software is at 0%, your slider is at 100% and you want to raise the volume?


You must move your slider down, and then up. It becomes reasonably intuitive with a small amount of practice :)


Could have feedback with a LED ramp next to slider, showing the discrepancy...


Down then up wouldn't be too bad, but up then down could very much be, in certain situations.


I would put a safety routine to let the software update only when the hardware is within a certain amount from the actual value, also giving visual feedback of the difference, so that the user could align hardware position to software position without any sudden changes.


You put the slider all the way down to 0, which is then mapped the the range from 0-0 and then you move it back up?!


Once the fader matches software, software follows the fader.




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