The pinout diagrams are simple, but they're easy to read, and especially helpful for beginners. You can print them out full size so you can set your Arduino Uno, ATMega, or ATTiny right on top for ...

Input and Output Each of the 14 digital pins on the Arduino Uno can be used as an input or output, using pinMode(), digitalWrite(), ... Arduino Uno Pinout. January 13, 2013 by P. Marian Comment 1.