Book Image

Raspberry Pi for Python Programmers Cookbook - Second Edition

Book Image

Raspberry Pi for Python Programmers Cookbook - Second Edition

Overview of this book

Raspberry Pi cookbook for Python Programmers is a practical guide for getting the most out of this little computer. This book begins by guiding you through setting up the Raspberry Pi, performing tasks using Python 3 and introduces the first steps to interface with electronics. As you work through each chapter you will build up your skills and knowledge and apply them as you progress throughout the book, delving further and further into the unique abilities and features of the Raspberry Pi. Later, you will learn how to automate tasks by accessing files, build applications using the popular Tkinter library and create games by controlling graphics on screen. You will harness the power of the built-in graphics processor by using Pi3D to generate your own high quality 3D graphics and environments. Connect directly to the Raspberry Pi’s hardware pins to control electronics from switching on LEDs and responding to push buttons right through to driving motors and servos. Learn how to monitor sensors to gather real life data and to use it to control other devices, and view the results over the Internet. Apply what you have learnt by creating your own Pi-Rover or Pi-Hexipod robots. Finally, we will explore using many of the purpose built add-ons available for the Raspberry Pi, as well as interfacing with common household devices in new ways.
Table of Contents (18 chapters)
Raspberry Pi for Python Programmers Cookbook - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Hardware and Software List
Index

Controlling servos directly with Servoblaster


The previous recipe demonstrated using a dedicated servo controller to handle the control of the servos used by the PiBug. This has the advantage that any disturbances in the processing taking place on the Raspberry Pi does not cause interference with the delicate servo control (since the controller will continue to send the correct signals).

However, the Raspberry Pi is also capable of direct servo control. To achieve this we will make use of Richard Hurst's Servoblaster, which is a multiple servo driver.

In this recipe, we will control four servos attached to the MeArm, a simple laser-cut robot arm; however, you can choose to fit servos to whatever device you like.

The MeArm is a simple robot arm powered by four miniature servos

Getting ready

Most common servos will have three wires and a three pin connector as follows:

Black/Brown

Red

Orange/White/Yellow/Blue

Ground

Positive Supply (Typically 5V for small servos)

Signal

While it is usually...