Switches and LEDs

The switches or toggles are connected to the PA/CA port of the PIO and are input devices. When their state changes, this will be reflected in PA (if the PIO is configured correctly). If PA is altered, the changes will not be reflected in the switches (they do not move on their own, so to speak).

The lights or LEDs are connected to the PB/CB port of the PIO and are output devices. The only way to change their state is by modifying PB. These changes will be reflected in the lights if the PIO is configured correctly; otherwise, the lights will appear to be off.