Hi!
I had no trouble getting data from "original" the powermate usb knob using
HID, but I can't seem to figure out how to use the newer versions (there
has been a firmware change). I can get the press data fine, but the
rotate data, which comes as relative offsets just like from a mouse, seems
to behave strangely. (I tested the knob with the provided driver and it
works fine there, so the knob itself is ok). I'm also told that it
behaves correctly through HID on windows machines.
When I look at the data in the HID Explorer, it never returns a 0 for
the displacement. When I stop moving the knob it drops down to 1 or -1
depending which way you were rotating, but never 0.
I verified this myself in my own code - the function "getElementValue" in
"IOHIDDeviceInterface" never seems to return 0 for the rotate element,
although it seems to return other displacement values appropriately.
I also tried using the event based queue methods for getting rotation
data, and got similarly odd results. I got an event for each change in
velocity (instead of continuous events, one for each displacement as I got
for the original knob), except the change to velocity 0 which was never
reported.
I am running 10.3.2 currently, but I saw the same behavior under jaguar.
Has anyone tried getting HID from the knobs? Or, has anyone seen a
similar problem? It seems like it might be that the rotate element is
getting misclasified as some other kind of element, one where only a
change in value is important, rather than each update being important
(like a joystick, maybe). Does this hypothesis make sense?
Any help will be greatly appreciated!
Thanks,
-jesse
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