Am I allowed to use the controller in pre-auton in order to pick which autonomous mode I’m doing, and to interact with the robot’s initialisation?(for example, the program will prompt the user to press x when he has put the arm in its starting position)
The V5 Brain cannot read the from the controller unless the competition state is driver control or disconnected (which defaults to driver control). You are better off using the Brain’s lcd for pre-auton configuration.
note that if you use the brain’s lcd for pre-auton selection of the auton to run, there is no way as of yet to use the skills programming selection of the controller to test your auton. you need to use a comp switch so the brain can be in “disabled” state to select the auton via lcd before entering auton, which via comp switch provides.
If you have a bunch of open 3 wire slots, you can use a jumper.
Jumpers for autonomous selection is soooo 2007. One of the other advantages to using the LCD is it looks cooler for the judges.