Potentially dangerous situation of HWSS (hardware safety switch) not working

ArduCopter
1

Setup:

  1. Set DISARM_DELAY parameter to 0 so that once the drone is armed, the motors keep spinning until explicitly disarmed.
  2. Configure motor emergency stop to be one of the spare channels on the transmitter.

The issue:

  1. Arm drone by pressing HWSS on the drone.
  2. Arm with joystick on transmitter. Motors will start spinning.
  3. Set motor emergency stop using the transmitter. Motors will stop spinning.
  4. Try to disarm by pressing the HWSS. It fails.

Now, I had some feedback which is that the drone must be manually disarmed with the transmitter joystick before using the HWSS to disarm it (step 4), but, surely for a safety issue like this, it would be best if the HWSS overrode everything else and disarmed the drone?

2

With bad weather, water can activate the HWSS. If HWSS has priority over everything, your vehicle would fall from the sky.
So that is why it does not have priority.

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3

If the weather is that bad, anything is possible!

If the drone is on the ground it should have priority.

If someone walks up to the drone on the floor and props aren’t spinning, the HWSS should have priority.

4

There is an option specially for you in the parameter BRD_SAFETYOPTION if you absolutely trust your safety switch.

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5

Thanks, I’ll try that.