Motor kill switch behavior

I recognized a slightly different behavior of the “motor stop” aux switch:
If i stop motors with this switch (already landed of course) and afterwards disarm properly, it’s impossible to arm again (message is “arm: motor emergency stop”)
One has power-cycle the pixhawk to arm again.
Is that a new feature or a bug ???

you have to put the E-stop switch back to the original position, you should then be able to arm

That was correct til now, but not in 4.0
Try it !

you sure this is a 4.0 issue? Might be worth re-calibrating your RC inputs.

Peter, thx for that advise, but i double checked everything before posting. The scenario is as follows (no props, on the bench):

  1. Pixhawk and TX is powered
  2. E-stop switch channel is at 1505 µs
  3. I can arm, motors spin
  4. E-stop switch is pushed, means 1900 µs
  5. Motors stop
  6. I disarm / copter disarms itself after a while
  7. E-stop switch is released, means 1505 µs
  8. I try to arm again, but that is not possible; instead i see the message “arm: motor emergency stop”

That is your issue, 1505 is not high enough to pass the dead zone, it needs to be at more than 1800 and less than 1200

ok, that’s the solution:
the E-stop channel has to go down to 1100 µs and THEN one can arm again !

That was different in 3.x


Yes, indeed, you’re right that we did (accidentally?) change this behaviour. In Copter-3.6 the middle and low position were considered the same (code) while in 4.0 the middle is ignored (code).

We could change it back to the old behaviour fairly easily… let’s think about this…

Thanks for the report.

I wouldn’t change it back. It’s safer to define the lower position that way. One just has to know it, so an addition to the docu is necessary

btw: 4.0 works flawless for me, no issues at all.

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