Control Surfaces and Actuators

To setup control surfaces and actuators follow: PX4 Actuator Configuration.

Control surface trims & prearm behavior

There are two ways to control the neutral position of a control surface:

• PWM_MAIN_CENTx / PWM_AUX_CENTx : always use these for PWM servos

• CA_SV_CSx_TRIM : use these for non-PWM servos

Whether or not the trim and center values are applied while the vehicle is disarmed is determined by the COM_PREARM_MODE parameter.

• 0 Disabled: surfaces sit at their PWM_*_DIS position

• 1 Safety Button: Trims are applied when a safety switch is flipped

• 2 Always: Trims are applied as soon as servos are powered

In general, we do recommend to set COM_PREARM_MODE=Always for easier on-ground preflight checks.