User manual

Fig. 2.7: An LED at GPIO port 25

2.4.1 How does it work?

The example shows the essential basic functions of the RPi.GPIO library.

import RPi.GPIO as GPIO The library RPi.GPIO must be imported into every Python program, that you are

going to use. By using the prefix

GPIO this notation can call all functions of the library.

import time The often used Python library time has nothing to do with GPIO programming. It contains

functions in terms of time and date calculation, including the

time.sleep function, which helps to

implement waiting times in a program in a very simple way.

GPIO.setmode (GPIO.BCM) When you start with any program the designation of GPIO ports must be

defined. Typically the default numbering

BCM is used.