SERVOX_ parameters and MANUAL mode

I have a question stemming for the new SERVOX_ parameters of the new 3.8 update.

Traditionally, we would configure our transmitter with the desired servo range (or at least approximately) and then did a radio calibration.
In this way, both in MANUAL and other modes the servo throws were the same.

However, in the new 3.8 update, the radio calibration philosophy only applies to the RC inputs, while the outputs are manually configured with the SERVOX_ parameters.

The question: I have set my transmitter range for (e.g.) channel 3 to be 1000-2000 for maximum resolution and the SERVO3 range at 1290-1750 so as to be within the mechanical range of my IC engine throttle body.
What will happen when I switch to MANUAL? My guess is that the new, raw, extended servo range will rip my throttle body out of the engine.

Is this intentional? Am I understanding the new parameters wrong?


no, it won’t do that. It will map the 1000-2000 range on the input to the 1290-1750 range of the output.
All modes do this now, whereas MANUAL used to be an exception. It means MANUAL is not direct pass-thru any more.
Cheers, Tridge

This is reassuring to hear, I was hoping to get that answer.

It raises another question though: At least in the PX4 IO board, rumour was that in case of processor hang, the IO board would passthrough the RC input channels to the output.

Was that carried through to Pixhawk 1 and 2 so far? How about with Plane 3.8?

The IO board does take over in case the FMU fails, but its not pass-thru. It builds a mixer file which emulates the functionality of MANUAL. So if FMU fails you should see the same functionality as MANUAL, and it won’t kill your servos.

Purrfect! Thanks for the information!

buen dia , hasta el momento yo configure un rango de salida con el SERVO3 según la apertura del carburador de mi motor, y pues la entrada RC3 se le configura de acuerdo al radio que tienes, normalmente se pone los valores al calibrar el radio, su máximo y su mínimo