Book Image

Raspberry Pi 3 Cookbook for Python Programmers - Third Edition

By : Steven Lawrence Fernandes, Tim Cox
Book Image

Raspberry Pi 3 Cookbook for Python Programmers - Third Edition

By: Steven Lawrence Fernandes, Tim Cox

Overview of this book

Raspberry Pi 3 Cookbook for Python Programmers – Third Edition begins by guiding you through setting up Raspberry Pi 3, performing tasks using Python 3.6, and introducing the first steps to interface with electronics. As you work through each chapter, you will build your skills and apply them as you progress. You will learn how to build text classifiers, predict sentiments in words, develop applications using the popular Tkinter library, and create games by controlling graphics on your screen. You will harness the power of a built in graphics processor using Pi3D to generate your own high-quality 3D graphics and environments. You will understand how to connect Raspberry Pi’s hardware pins directly to control electronics, from switching on LEDs and responding to push buttons to driving motors and servos. Get to grips with monitoring sensors to gather real-life data, using it to control other devices, and viewing the results over the internet. You will apply what you have learned by creating your own Pi-Rover or Pi-Hexipod robots. You will also learn about sentiment analysis, face recognition techniques, and building neural network modules for optical character recognition. Finally, you will learn to build movie recommendations system on Raspberry Pi 3.
Table of Contents (23 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Index

Networking and connecting your Raspberry Pi to the internet via an Ethernet port, using a CAT6 Ethernet cable


The simplest way to connect Raspberry Pi to the internet is by using the built-in LAN connection on the Model B. If you are using a Model A Raspberry Pi, a USB-to-LAN adapter can be used (refer to the There's more... section of the Networking and connecting your Raspberry Pi to the internet via a USB Wi-Fi dongle recipe for details of how to configure this).

Getting ready

You will need access to a suitable wired network, which will be connected to the internet, and a standard network cable (with an RJ45 type connector for connecting to Raspberry Pi).

How to do it...

Many networks connect and configure themselves automatically using the Dynamic Host Configuration Protocol (DHCP), which is controlled by the router or switch. If this is the case, simply plug the network cable into a spare network port on your router or network switch (or wall network socket if applicable).

Alternatively, if a DHCP server is not available, you shall have to configure the settings manually (refer to the There's more... section for details).

You can confirm this is functioning successfully with the following steps:

  1. Ensure that the two LEDs on either side of Raspberry Pi light up (the left orange LED indicates a connection and the green LED on the right shows activity by flashing). This will indicate that there is a physical connection to the router and that the equipment is powered and functioning.
  2. Test the link to your local network using the ping command. First, find out the IP address of another computer on the network (or the address of your router, perhaps, often 192.168.0.1 or 192.168.1.254). Now, on the Raspberry Pi Terminal, use the ping command (the -c 4 parameter is used to send just four messages; otherwise, press Ctrl + C to stop) to ping the IP address, as follows:
sudo ping 192.168.1.254 -c 4
  1. Test the link to the internet (this will fail if you usually connect to the internet through a proxy server) as follows:
sudo ping www.raspberrypi.org -c 4
  1. Finally, you can test the link back to Raspberry Pi by discovering the IP address using hostname -I on Raspberry Pi. You can then use the ping command on another computer on the network to ensure it is accessible (using Raspberry Pi's IP address in place of www.raspberrypi.org). The Windows version of the ping command will perform five pings and stop automatically, and will not need the -c 4 option.

If the aforementioned tests fail, you will need to check your connections and then confirm the correct configuration for your network.

There's more...

If you find yourself using your Raspberry Pi regularly on the network, you won't want to have to look up the IP address each time you want to connect to it.

On some networks, you may be able to use Raspberry Pi's hostname instead of its IP address (the default is raspberrypi). To assist with this, you may need some additional software, such as Bonjour, to ensure hostnames on the network are correctly registered. If you have macOS X, you will have Bonjour running already.

On Windows, you can either install iTunes (if you haven't got it), which also includes the service, or you can install it separately (via the Apple Bonjour Installer available from https://support.apple.com/kb/DL999). Then you can use the hostname, raspberrypi or raspberrypi.local, to connect to Raspberry Pi over the network. If you need to change the hostname, then you can do so with the Raspberry Pi configuration tool, shown previously.

Alternatively, you may find it helpful to fix the IP address to a known value by manually setting the IP address. However, remember to switch it back to use DHCP when connecting to another network.

Some routers will also have an option to set a Static IP DHCP address, so the same address is always given to Raspberry Pi (how this is set will vary depending on the router itself).

Knowing your Raspberry Pi's IP address or using the hostname is particularly useful if you intend to use one of the remote access solutions described later on, which avoids the need for a display.