I added to my boat some externally mounted pins for measuring the conductivity of the water the boat is in by using one of the little rain sensor boards, it occurred to me that it could also be used as a motor safety system to lock out throttle control until the boat is in water. this could be a very useful feature if you have large propellers on the boat.
its essentially just using the digital output from this sensor
Enable the button using the BTN_ENABLE set to 1 and reload parameters to get the rest of the button settings to appear.
Then i set BTN_PIN1 = 55 or AUX6 on a pixhawk, setting the pin the water sensor will connect to.
we then have to set the BTN_FUNC1 = 31 Motor Emergency Stop, now the motors wont run unless the boat is in the water.
