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.

When you need more inputs/outputs for your Arduino project, the response in some forums is "Use a MEGA" instead. While the Arduino MEGA does have more built-in GPIO pins (70 digital input/output pins, ...

There is a boring part of every computer introduction class that shows how a computer is made up of input, output, and processing. Maybe it wouldn’t be so boring if the input device was a nun… ...