I have wired and fitted the new Rotary encoder to the Arduino and am getting the same problem.
The encoder is built for the Arduino board (Mega 2560) and can be seen here:
The wiring was done like this:
• Encoder CLX pin to Arduino pin 21
• Encoder DT pin to Arduino pin 20
• Encoder SW pin to Arduino pin 19
• Encoder GND pin to Arduino ground pin
• Encoder + pin not connected.
The Mobiflight configuration was as follows:
Input - Type Encoder:
• Left – FSUIPC Control no 66278
• Left fast – FSUIPC Control no 66278
• Right – FSUIPC Control no 66279
• Right fast – FSUIPC Control no 66279
Input - Type Switch:
• Switch - FSUIPC Control no 66732 Param 0
• Windows 10 64 bit
• P3D v4.2
• FSUIPC v5
• Mobiflight v7.4.0
Cause of symptoms:
When the encoder is used the value of SEE_SELF in the Prepar3D.cfg file is set to 0 (Zero). This causes the external views to not see the aircraft. So if I run Mobiflight and connect to FSUIPC all appears good with the normal switches working as they should. The SEE_SELF parameter is set to 1.
However as soon as I move the rotary encoder’s knob the aircraft disappears. If this is done whilst viewing the outside of the aircraft it vanishes in front of your eyes!
A check on the SEE_SELF value finds that it is now set to 0 (zero). Manually changing this value back to 1 restores the aircraft outside view until you use the encoder again.
I hope this provides enough information for any investigation.
Edit: There is an FSUIPC Control no for the SEE_SELF value in the list of FSUIPC Control nos. It is 66118. This I did not use and it is sufficiently different to have been used in error.