make mavlink rc channels override working as 2nd serial reciver

[krzysztofkuczek]

Hi,
It makes possible to control rc channels via mavlink even if standard serial rx (sbus or other) is in use. The rc channels values recived from mavlink are valid for a time defined by new mavlink_chn_override_timeout_ms parameters. So if you want to keep mavlink override rc channels you need to send a RC_CHANNELS_OVERRIDE more freqently that the mavlink_chn_override_timeout_ms. The timeout is calculated for every single channel.

[krzysztofkuczek]

@DzikuVx, I updated the Settings.md .
Miłego dnia :)
Krzysiek

[sensei-hacker]

This could be good if someone wants to resolve the conflicts.

[sensei-hacker]

There's a fresh, actively-developed PR for dual/switchable receivers: #11748 (New Feature: Dual switchable receivers) — may be a better path forward for this use case than resolving the conflicts here.

[b14ckyy]

Closing as superseded. The MAVLink stack has been restructured since this was written, and the use case is covered in two safer ways now: a GCS on the MAVLink port can use the MSP-over-MAVLink tunnel (#11718) with the existing MSP RC Override, which adds the switch gate, channel mask and failsafe handling this change did not have; and a second physical receiver with failover is being worked on in #11748. An ungated per-channel override of flight channels from any MAVLink sender is not something we would merge on its own.