SBC and Alternatives
This document explains common use during the operation of SBC (Single-board Computers), such is Raspberry Pi, Banana Pi and others.
Detail instruction for SBC(s) below:
Check How to mount SD Cards notes for instruction on how to mount /boot and ext4 partitions directly from the Host OS. Some ext4 partition mounting explained in MacOS Notes.
Detailed instructions for Enabling SSH on Raspbian OS are also available.
Raspberry Pi GPIO
A powerful feature of the Raspberry Pi is the row of GPIO (general-purpose input/output) pins along the top edge of the board. A 40-pin GPIO header is found on all current Raspberry Pi boards (unpopulated on Raspberry Pi Zero, Raspberry Pi Zero W and Raspberry Pi Zero 2 W). Prior to the Raspberry Pi 1 Model B+ (2014), boards comprised a shorter 26-pin header.
Any of the GPIO pins can be designated (in software) as an input or output pin and used for a wide range of purposes.
A handy reference can be accessed on the Raspberry Pi by opening a terminal window and running the command
pinout.