I have a question about how the "Button" example is wired. (Link here: http://arduino.cc/en/Tutorial/Button)
In the example, a 10k ohm resister is added as a pull down (or pull up if wired slightly differently) resistor. I note in other documentation that a 20k pull up resistor is built into the Atmega chip that can be turned on by issuing a digitalWrite(pin, HIGH) command after setting a pin to input.
Does this mean the circuit in the example (if reversed so the 10k resister is used as a pull up resistor) could be simplified by simply turning on the internal 20k pull up resistor and wiring GND to the button and then directly to pin 2 without an external resistor?
Just seeking clarification that I'm understanding things correctly. Thanks.