I have setup my Taranis to use safe arming with two switches just like JB explained it in his video:
Safer Switch Arming on FrSky Taranis
For convenience I wanted to get this working on my Jumper T8 too. I also wanted to explore the possibilities of the virtual channels and the complex mixers. After an afternoon fiddling around I came up with this solution:
[virtchan1]
template=complex
[mixer]
src=!THR
dest=Virt1
switch=SW H1
usetrim=0
curvetype=min/max
points=98
[mixer]
src=AIL
dest=Virt1
switch=SW H0
scalar=-100
usetrim=0
curvetype=fixed
[virtchan2]
template=complex
[mixer]
src=SW D1
dest=Virt2
switch=Virt1
scalar=-100
usetrim=0
curvetype=less-than-0
points=0
[mixer]
src=AIL
dest=Virt2
switch=SW D1
scalar=-100
usetrim=0
curvetype=fixed
What it does: It is arming the model if both the shoulder switch H and switch G are triggered simultaneously and the throttle is below -98 at lowest position. The motor disarms immediately when switch G is put back in the middle position. You can change the disarm behaviour to a two switch disarming if you don't put in the second mixer on virtchan2. In this case the model will disarm when switch G is the middle position and shoulder switch H is flipped. The output of virtchan2 is 100 if the model should be armed and -100 to disarm. If you want to use it as a safety switch in a channel then you must invert the output of virtchan2:
[channel3]
safetysw=!Virt2
safetyval=-150
There are two caveats: Firstly, I have changed the shoulder switch H on my Jumper T8 to a momentary switch, just as it is on my Taranis. My solution is only practical if you use shoulder switch H as a momentary switch: Flip it for arming then set it directly back to the default position. Secondly this won't work for inverted flight modes.
Feel free to comment if you have ideas to implement this feature in a more simplistic way. But bare in my mind that this was my first dealing with complex mixers and virtual channels.
