Behringer USB mode synch noise of motor

[rsjaffe]

From @Henk72 on September 24, 2015 22:2

Hi,

When using the BCF2000 it seems every time after a slider change has been made, some kind of update happens. You feel the slider move (but not really) as if it is synching and the MIDI A+B channel lights briefly light up. This also happens in mode U1 (only USB, no MIDI).
This does not happen with the Paddy program. I was wondering if this can be prevented.

Gr. Henk

Copied from original issue: thegouger/MIDI2LR#53

[rsjaffe]

From @Henk72 on September 25, 2015 8:0

It could be that there is some kind of synch loop. First the BCF2000 makes a change to a parameter, then it is send to Lightroom who in turn sends the value again to the BCF2000. If this is the case, the last step should be omitted if there is no parameter delta.

[rsjaffe]

From @thegouger on September 25, 2015 14:37

I think what's happening is that when LR creates a history entry, it changes the value of the affected parameters. As a result, there's a slight difference between the linearly interpolated value and this new value, so it sends another update.

[rsjaffe]

From @Henk72 on September 25, 2015 15:22

Might there be a solution to filter for these small rounding issues, preventing the unnecessary update? If you now move the slider but still keep your hand on it and decide to move it again which can coincide with the update, you are moving against the motor power (not good). It already happened a few times.

[rsjaffe]

I'd change the way the lua code speaks to the C++ code and vice versa. This would pave the way for setting the midi controls to wider ranges than 0-127, which would solve a whole bunch of other issues.

So I'd normalize the LR setting range from 0-100 instead of the current 0-127 in the lua code, change the formatting for sending the value to the C++ app from %d to %g, and have the C++ app handle the mapping to the MIDI control ranging. That alone might take care of the rounding issue above.

This does mean that the C++ app would have to handle the value as float instead of int, and then map to/from and int value for the MIDI control range when communicating with the control surface.

Then we could work on allowing expanded-range MIDI controls, which the Behringer control surfaces support. I have some ideas on that, but we'd have to change the above first.

[rsjaffe]

See #31