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

Multiplexed color LEDs


The next example in this chapter demonstrates that some seemingly simple hardware can produce some impressive results if controlled with software. For this, we will go back to using RGB LEDs. We will use five RGB LEDs that are wired so that we only need to use eight GPIO pins to control their red, green, and blue elements using a method called hardware multiplexing (see the Hardware multiplexing subsection in the There's more... section of this recipe).

Getting ready

You will need the RGB LED module shown in the following picture:

The RGB LED module from PiHardware.com

As you can see in the preceding photo, the RGB LED module from http://pihardware.com/ comes with GPIO pins and a DuPont female-to-female cable for connecting it. Although there are two sets of pins labelled from 1 to 5, only one side needs to be connected.

Alternatively, you can recreate your own with the following circuit using five common cathode RGB LEDs, 3 x 470 ohm resistors, and a Vero prototype board...