Add crsf-bind button

[benjinne]

Adds crsf-bind button.
Based on:

• crsf_rc: add bind command PX4/PX4-Autopilot#23294
  and
• add rc_type_crsf mavlink#2162

Test Steps

The button successfully sets a CRSF (crossfire, ELRS, etc) receiver into bind mode

[HTRamsey]

Looks fine to me, do you know if there is an enum available for the rxType?

Edit: Nevermind, I saw your discussion on the other PR

[DonLakeFlyer]

@benjinne What happens on the firmware side if you try a CSRF bind on an older firmware that doesn't support this?

[DonLakeFlyer]

Also now that the RC_TYPE_foo enums have been added to mavlink can the code be updated to use both of those?

[benjinne]

@benjinne What happens on the firmware side if you try a CSRF bind on an older firmware that doesn't support this?

I believe nothing happens. The version of ELRS supported is 3.4.0+
https://www.expresslrs.org/quick-start/binding/?h=bind#updated-binding-procedure-since-expresslrs-340

[DonLakeFlyer]

I looked at the ArduPilot code and it's going to get confused by this. It will cause Spektrum bind to start. Are there plans to support this in ArduPilot as well? If not, then I would say this show for PX4 only.

[benjinne]

Also now that the RC_TYPE_foo enums have been added to mavlink can the code be updated to use both of those?

I looked at the ArduPilot code and it's going to get confused by this. It will cause Spektrum bind to start. Are there plans to support this in ArduPilot as well? If not, then I would say this show for PX4 only.

I'll take a look. I think I can use the enum and we can update ArduPilot

[DonLakeFlyer]

Ok, so assuming ArduPilot gets updated as well. Then I'll merge once the magic numbers are fixed.

[DonLakeFlyer]

Fantastic, thanks