I’m running Arducopter V3.6.0-rc6 on a PixHawk(1), set up as a quad. I have two extra motors (larger) that are both connected to SERVO output 5. When I set SERVO5_FUNCTION to option to “81” and MOT_BOOST_SCALE to “2” and reboot, these values are read back to MP every time I connect via telemetry, but SERVO5 does not produce an output. If I change SERVO5_FUNCTION to some other value (like “53” and do NOt reboot, then SERVO5 mirrors the throttle (CHAN 3) input as expected. If I then change SERVO5_FUNCTION to “81” (again without rebooting), it does what is stated in the documentation (outputs a scaled “internal” throttle value). But when I remove power and restart, SERVO5 has no output - even though telemetry tells me those functions are set to “81” and “2” respectively. In order to get the function to work, I have to manually set SERVO5_FUNCTION to “81” every time I power up. It seems these values aren’t automatically read on every power up or reboot.
This also brings up what I consider to be another problem : As soon as I WRITE the change and set the servo function to 81, the servo output immediately goes to the minimum value - BEFORE the safety switch is pushed and before arming. I think the output should remain inactive before the safety switch is pushed (at least).