Change Modes Channel

Using ExpressLRS receiver. ExpressLRS site says to use channel 5 for Arm/Disarm, yet Ardupilot channel 5 “default” for copters is modes.

I think (not sure) I can change channel 5 to Arm/Disarm through a switch on transmitter by using this parameter RC5_OPTION = 41 and setting up the switch in the transmitter on channel 5 (Mixes Page). Will this work?

If so, is it then possible to put “Modes” on a different channel (such as channel 6) and use a 3-position switch on that one channel to change between 3 different Modes? If so, what parameter do I need to change and to what value? Is it FLTMODE_CH = 6?
Thank you

Yes that would be it

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Thank you so much. New to Ardupilot and having fun learning!

Hi,
I’m also having a confusion regarding this channel 5 arming on ELRS:
ELRS devs say that I “would better have channel 5 at high when armed” and it’s something beyond my understanding. Along with this channel 5 on ELRS is a 1 bit and it’s sent on every frame? frequently. I feel much safer arming by throttle, and also I have on my Radiomaster TX16S a 6-pos button ideal for mode switch, but I can’t set it on channel 5, because it’s 1 bit. Also my quad arms fine while channel 5 at low.
Maybe it’s some old time superstition, but still a mysterious religious fear keeps me from setting rings and bells on this switch.
What should I do with it?

you could try asking on the ELRS discord ExpressLRS Community. I have also been curious about this as I have a mini that I just use rudder arming with and that seems to be ok.

You definitely want to set channel 5 high during flight, at least under present ELRS firmware. It sets some flags for transmission as well. You can probably just set a global function as Ch5 high and let ArduPilot ignore it as an arming command.

ELRS 3.0 brings some improvements to this mess and is the chief reason I’m considering switching over to ELRS in the near future.

I have already switched to ELRS 3.0 RC. Just wanted to get 16 channels badly)
Now does that meat that I can forget all this warnings and recommendations regarding channel 5 and use it whatever I want?

Yes! Forget ch5 in that mode! (Or at least that’s my understanding at present)

@Yuri_Rage

so even on 2.xx you would still put channel 5 high even when using rudder arming? I was actually surprised rudder arming worked as i thought arming had to be in ch5.

From everything I’ve read/seen, Ch5 should be high when in a ready-for-flight mode. I was trying to find some more specific documentation on the rationale yesterday and came up empty. Some of the videos by the likes of Painless360 and RC Reviews discuss it in some detail.

Actually, here is the one of the ELRS dev team tells that even in 3.0 RC channel 5 still has to be high for the “link optimization be active”. I suppose, that means that otherwise ELRS will think that the aircraft is on the ground with some magic circumstances.

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