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

Using devices with the I2C bus


Raspberry Pi can support several higher-level protocols that a wide range of devices can easily be connected to. In this chapter, we shall focus on the most common bus, called I-squared-C (I2C). It provides a medium-speed bus for communicating with devices over two wires. In this section, we shall use I2C to interface with an 8-bit ADC. This device will measure an analog signal, convert it to a relative value between 0 and 255, and send the value as a digital signal (represented by 8-bits) over the I2C bus to the Raspberry Pi.

The advantages of I2C can be summarized as follows:

  • Maintains a low pin/signal count, even with numerous devices on the bus
  • Adapts to the needs of different slave devices
  • Readily supports multiple masters
  • Incorporates ACK/NACK functionality for improved error handling

Getting ready

The I2C bus is not enabled in all Raspberry Pi images; therefore, we need to enable the module and install some supporting tools. Newer versions of Raspbian use device...