Board Pinout

Pins labeled A0-A7 are analog inputs.

Pins labeled D0-D13 are for digital I/O. However, some of these pins have specialized uses. Notably, D0,D1 are interrupt inputs and D2,D3 are Serial I/O.

Not interested (for now) in other specialized pin usage, we can count with 10 digital pins: D4-D13.