I'm using an Arduino Uno to control a small robot and I'm starting to add micro-switches as bump-sensors. I know that when I'm creating a circuit with LEDs I need to use resistors to limit the current so I don't mess up the Arduino, but do I need to do the same with the micro-switches? If so, how do I calculate the necessary resistance?
If it makes a difference, my micro-switch is Pololu #1405, Snap-Action Switch with 15.6mm Bump Lever 3-pin, SPDT, 5A. The Arduino outputs 5V and has a maximum of 40mA.
EDIT: I've done some more research and I found a page that seems to describe exactly what I want to do (http://arduino.cc/en/tutorial/button), don't know how I missed it before. So if I'm understanding the situation correctly, the only resistor I need is the pull-up/down one between the switch and ground, but none between the switch and the pin that's reading the switch.