A very basic question:
Must each IO pin of a microcontroller that is serving as an input from a switch or jumper have its own pull-up/down resistor?
In this example, each pin is pulled down by a resistor, then pulled up by a 1P3T switch to VCC.
It seems straightforward, but as more IO pins are used, are more resistors absolutely required? Is there some clever way to keep the resistor count down?
Related question: Sharing a pull-up resistor