After almost loosing a boat to a glitch in the minipix (or a programming error), I decided to incorporate a safety switch to turn control back to my receiver.
I’m using a 12ch receiver and sbus communication to the minipix. So to switch control from the minipix to my receiver, I did the following. I wired the motor and rudder outputs of the minipix and receiver through a dpst NC micro relay triggered by a pwm switch on my receiver’s channel 7. With the switch off, my signal wires are passed from the minipix to the motor and rudder. If the minipix has a brain fart, I turn on channel 7 activating the relay, which now passes the signal wires from my receiver to the motor and rudder giving me full manual control. Now I can navigate my boat back to the dock rather than watching it disappear into the horizon.
Hopes this helps others.