/*
Input Pullup Serial
This example demonstrates the use of pinMode(INPUT_PULLUP). It reads a
digital input on pin 2 and prints the results to the serial monitor.
The circuit:
* Momentary switch attached from pin 2 to ground
* Built-in LED on pin 13
Unlike pinMode(INPUT), there is no pull-down resistor necessary. An internal
20K-ohm resistor is pulled to 5V. This configuration causes the input to
read HIGH when the switch is open, and LOW when it is closed.
created 14 March 2012
by Scott Fitzgerald
http://www.arduino.cc/en/Tutorial/InputPullupSerial
This example code is in the public domain
*/