Appendix - GPIO Pins

The GPIO pin charts below are for the Raspberry Pi 3 Model B V1.2

You have a choice of two numbering systems in Python. Import the RPi.GPIO module:

import RPi.GPIO as IO
IO.setmode(GPIO.BOARD)

Or:

import RPi.GPIO as IO
IO.setmode(GPIO.BCM)

The GPIO.BOARD mode uses the numbers in the gray rectangles from 1 to 40.

The GPIO.BCM refers to the pins by the "Broadcom SOC channel" number.These are the numbers after the "GPIO" in the coloured rectangles. These numbers changed between model B versions of the Raspberry Pi.

It is safer if you use GPIO.BOARD numbers in your Python programs, especially if you have an older Raspberry Pi model.

For general input output circuits we suggest you only use the pins with the orange outline around the grey boxes.

GPIO Diagram without Pi

GPIO Diagram

GPIO Diagram with Pi

GPIO Diagram with Pi