Getting Started with Python for the Internet of Things

Leverage the full potential of Python to prototype and build IoT projects using the Raspberry Pi

Tim Cox, Dr. Steven Lawrence Fernandes, Sai Yamanoor, Srihari Yamanoor, Prof. Diwakar Vaish

• Publisher: Packt Publishing
• Year: 2019
• ISBN:
  9781838553333
• Edition: 1
• Topic: Computer Science
• Subtopic: Programming in Python
• Index: Computer Science

Build clever, collaborative, and powerful automation systems with the Raspberry Pi and Python.Key Features• Create your own Pi-Rover or Pi-Hexipod robots• Develop practical applications in Python using Raspberry Pi• Build your own Jarvis, a highly advanced computerized AIBook DescriptionThis Learning Path takes you on a journey in the world of robotics and teaches you all that you can achieve with Raspberry Pi and Python.It teaches you to harness the power of Python with the Raspberry Pi 3 and the Raspberry Pi zero to build superlative automation systems that can transform your business. You will learn to create text classifiers, predict sentiment in words, and develop applications with the Tkinter library. Things will get more interesting when you build a human face detection and recognition system and a home automation system in Python, where different appliances are controlled using the Raspberry Pi. With such diverse robotics projects, you'll grasp the basics of robotics and its functions, and understand the integration of robotics with the IoT environment.By the end of this Learning Path, you will have covered everything from configuring a robotic controller, to creating a self-driven robotic vehicle using Python.• Raspberry Pi 3 Cookbook for Python Programmers - Third Edition by Tim Cox, Dr. Steven Lawrence Fernandes• Python Programming with Raspberry Pi by Sai Yamanoor, Srihari Yamanoor• Python Robotics Projects by Prof. Diwakar VaishWhat you will learn• Build text classifiers and predict sentiment in words with the Tkinter library• Develop human face detection and recognition systems• Create a neural network module for optical character recognition• Build a mobile robot using the Raspberry Pi as a controller• Understand how to interface sensors, actuators, and LED displays work• Apply machine learning techniques to your models• Interface your robots with BluetoothWho this book is forThis Learning Path is specially designed for Python developers who want to take their skills to the next level by creating robots that can enhance people's lives. Familiarity with Python and electronics will aid understanding the concepts in this Learning Path.

Getting Started with a Raspberry Pi 3 Computer

In this chapter, we will cover the following topics:

• Connecting peripherals to Raspberry Pi
• Using NOOBS to set up your Raspberry Pi SD card
• Networking and connecting your Raspberry Pi to the internet via the LAN connector
• Using built-in Wi-Fi and Bluetooth on Raspberry Pi
• Configuring your network manually
• Networking directly to a laptop or computer
• Networking and connecting your Raspberry Pi to the internet via a USB Wi-Fi dongle
• Connecting to the internet through a proxy server
• Connecting remotely to Raspberry Pi over the network using VNC
• Connecting remotely to Raspberry Pi over the network using SSH (and X11 forwarding)
• Sharing the home folder of Raspberry Pi with SMB
• Keeping Raspberry Pi up to date

Introduction

This chapter introduces Raspberry Pi 3 and the process of setting it up for the first time. We will connect Raspberry Pi to a suitable display, power, and peripherals. We will install an operating system on an SD card. This is required for the system to boot. Next, we will ensure that we can connect successfully to the internet through a local network.

Finally, we will make use of the network to provide ways to remotely connect to and/or control Raspberry Pi from other computers and devices, as well as to ensure that the system is kept up to date.

Once you have completed the steps within this chapter, your Raspberry Pi will be ready for you to use for programming. If you already have your Raspberry Pi set up and running, ensure that you take a look through the following sections, as there are many helpful tips.

Introducing Raspberry Pi

The Raspberry Pi is a single-board computer created by the Raspberry Pi Foundation, a charity formed with the primary purpose of re-introducing low-level computer skills to children in the UK. The aim was to rekindle the microcomputer revolution of the 1980s, which produced a whole generation of skilled programmers.

Even before the computer was released at the end of February 2012, it was clear that Raspberry Pi had gained a huge following worldwide and, at the time of writing this book, has sold over 10 million units. The following image shows several different Raspberry Pi models:

The Raspberry Pi Model 3B, Model A+, and Pi Zero

What's with the name?

The name, Raspberry Pi, was a combination of the desire to create an alternative computer with a fruit-based name (such as Apple, BlackBerry, and Apricot) and a nod to the original concept of a simple computer that could be programmed using Python (shortened to Pi).

In this book, we will take this little computer, find out how to set it up, and then explore its capabilities chapter by chapter, using the Python programming language.

Why Python?

It is often asked, "Why has Python been selected as the language to use on Raspberry Pi?" The fact is that Python is just one of the many programming languages that can be used on Raspberry Pi.

There are many programming languages that you can choose, from high-level graphical block programming, such as Scratch, to traditional C, right down to BASIC, and even the raw machine code assembler. A good programmer often has to be code multilingual to be able to play to the strengths and weaknesses of each language to best meet the needs of their desired application. It is useful to understand how different languages (and programming techniques) try to overcome the challenge of converting what you want into what you get, as this is what you are trying to do as well while you program.

Python has been selected as a good place to start when learning about programming, as it provides a rich set of coding tools while still allowing simple programs to be written without fuss. This allows beginners to gradually be introduced to the concepts and methods on which modern programming languages are based without requiring them to know it all from the start. It is very modular with lots of additional libraries that can be imported to quickly extend the functionality. You will find that, over time, this encourages you to do the same, and you will want to create your own modules that you can plug into your own programs, thus taking your first steps into structured programming.

Python addresses formatting and presentation concerns. As indentation will add better readability, indents matter a lot in Python. They define how blocks of code are grouped together. Generally, Python is slow; since it is interpreted, it takes time to create a module while it is running the program. This can be a problem if you need to respond to time-critical events. However, you can precompile Python or use modules written in other languages to overcome this.

It hides the details; this is both an advantage and a disadvantage. It is excellent for beginners but can be difficult when you have to second-guess aspects such as datatypes. However, this in turn forces you to consider all the possibilities, which can be a good thing.

Python 2 and Python 3

A massive source of confusion for beginners is that there are two versions of Python on Raspberry Pi (Version 2.7 and Version 3.6), which are not compatible with each other, so code written for Python 2.7 may not run with Python 3.6 (and vice versa).

The Python Software Foundation is continuously working to improve and move forward with the language, which sometimes means they have to sacrifice backward compatibility to embrace new improvements (and, importantly, remove redundant and legacy ways of doing things).

Supporting Python 2 and Python 3

There are many tools that will ease the transition from Python 2 to Python 3, including converters such as 2to3, which will parse and update your code to use Python 3 methods. This process is not perfect, and in some cases you'll need to manually rewrite sections and fully retest everything. You can write the code and libraries that will support both. The import __future__ statement allows you to import the friendly methods of Python 3 and run them using Python 2.7.

Which version of Python should you use?

Essentially, the selection of which version to use will depend on what you intend to do. For instance, you may require Python 2.7 libraries, which are not yet available for Python 3.6. Python 3 has been available since 2008, so these tend to be older or larger libraries that have not been translated. In many cases, there are new alternatives to legacy libraries; however, their support can vary.

In this book, we have used Python 3.6, which is also compatible with Python 3.5 and 3.3.

The Raspberry Pi family – a brief history of Pi

Since its release, Raspberry Pi has come in various iterations, featuring both small and large updates and improvements to the original Raspberry Pi Model B u...