The GPIO pins can be divided into a number of categories. These are:
Standard GPIO
I2C
Serial Rx and Tx
SPI
PWN and PPM
Let's begin by looking at the standard GPIO pins and understanding what they do. A diagram with a breakdown of the pins can be downloaded from https://www.raspberrypi.org/documentation/usage/gpio-plus-and-raspi2/images/physical-pin-numbers.png.
A general overview of the GPIO pins can also be found at the Raspberry Pi website at https://www.raspberrypi.org/documentation/hardware/raspberrypi/gpio/README.md.
The standard GPIO pins on your Raspberry Pi 2 provide an interface for other electronic devices you may wish to either control or read data from.
These pins can be configured as output or inputs. As you will in see in the Python and C programs we will write, it is possible to programmatically switch between the two.
One important thing to note is the numbering format. There are two different ways in which we can refer to the pins, via the GPIO...