airskin disable some pads

[mzillich]

add configuration to disable pads if they are not needed

[bajo]

@mzillich could we integrate a service to enable/disable specific pads on the fly?
This might be useful while moving the arm out of the parking position and having the chance to hit the pan/tilt mounting rod as it is now or to disable all of them while the arm is in parking position to make sure we do not get stuck if a cable or something else accidentally touches the airskin.

[mzillich]

Nice idea! That would not go through TÜV ... but it is very handy ;)
I will add that to the airskin node.