Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "We have to multiply 2 and 3 we simply write Multiply(2,3)."

A block of code is set as follows:

import RPi.GPIO as GPIO
from time import sleep 
GPIO.setmode(GPIO.BOARD) 
GPIO.setup(23,GPIO.OUT) 

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

import RPi.GPIO as GPIO
from time import sleep 
GPIO.setmode(GPIO.BOARD) 
GPIO.setup(23,GPIO.OUT) 

Any command-line input or output is written as follows:

sudo apt-get update
sudo apt-get upgrade

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Then select I2C to enable it. Then select Yes."

Warnings or important notes appear like this.

Tips and tricks appear like this.