Not exactly schematics, but [Duckman] has some Arduino pinout diagrams he made using ASCII-art. These could be useful when pasted into source code as comments, documenting the pinouts for your ...

PWM pins work the same way across all Arduino boards, so you don't need to go out of your way to buy a Mega if you already have a board supporting PWM. On the Uno, Nano, and Mini, the PWM pins are ...