Conventions for handling channel inversions?

Hey Forum

Question about existing conventions for handling sign inversions on RC channels. There are lots of places this can be handled and I'd like to match what is most commonly done across all protocols. Lets say the sign of the roll channel needs to be inverted.

Which of these is most correct or most common?
- In the protocol code itself in deviation
- In the receiver firmware
- Hard coded in the flight controller implementation
- Done by the user in the flight controller configuration
- Done by the user in the Deviation options menu (by setting a channel to be inverted)

Edit: Same question applies to channel ordering -- should a protocol implementation re-order devo channels to what the target expects or should it be left up to the user to manually remap channels in the deviation menus?

Thoughts?
Thanks
Sean

Inversion is normally handled by the user in the deviation configuration. Channel ordering is in the protocol code in deviation.

This is all historical artifact, though. Older models - predating flight controllers and transmitters that had configurable channels (I vaguely recall seeing a bug report for OpenTx that it had the wrong channel order when you put a DSM RF module in a TH9X : -) assumed that the channel order and inversion were handled by the transmitter, so deviation had to do that. The proprietary transmitters from that era don't have a configurable protocol (except by swapping rf modules if they have that option) or configurable channel order. So for most of them, the channel order and protocol are both fixed, so any receivers that work with that protocol have to use that channel order, so the channel order is effectively part of the protocol. So much so that the PWM outputs on standalone Rx's are labelled with channel names (which is why deviation fixes those names in the mixer page) and the aircraft transmitter configuration instructions normally use the names of inputs, not channel numbers. Of course, if you have an rf module bay, then the channel order configuration is done in the transmitter module firmware, a possibility you didn't mention.