Always given the IO pin define: LED_BUILTIN Will be automatically set as an output

Setup Pin Mode Set Outputs Read Inputs Using a variable: Using directly: Analog Pins As General IO The analog pins can be used identically to the digital pins, using the aliases A0, A1, etc. Device Pin Numbers You should always use Arduino pin numbers (e.g. 1, 2, 3, A0, A1, A2) and not device port […]