How to change Scale and Offset with trim? Throttle

Hello everyone,

I would like to program the throttle channel on an aircraft with an internal combustion engine.

Task / goal:

- Normal linear 3 point curve (P1: -100 / P2: 0 / P3: +100)

- The trim should only be able to change the points P1 and P2.

- Point P3 should always remain constant (P3 = +100). Point P3 should not be influenced by the trim and should remain constant (P3 = +100).

See also the sketch/picture in the appendix.


Why all this:
The reason for this is that the trim can be used to adjust the idle throttle (or idle speed). The full throttle position should not be influenced by the trim. When the idle speed is reduced by the trim, the throttle valve should be fully open in the full throttle position.

How can I realize this task? How do I have to program this? I have the Devo10. Thank you very much for your help and support. Please send me suggestions, solutions and ideas. Many thanks in advance!

Best regards
Martin