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

Writing messages using Persistence of Vision


Persistence of Vision (POV) displays can produce an almost magical effect, displaying images in the air by moving a line of LEDs back and forth very quickly or around in circles. The effect works because your eyes are unable to adjust fast enough to separate out the individual flashes of light, and so you observe a merged image (the message or picture being displayed).

Persistence of vision using RGB LEDs

Getting ready

This recipe also uses the RGB LED kit used in the previous recipe; you will also need the following additional items:

  • Breadboard (half-sized or larger)

  • 2 x Dupont female to male patch wires

  • Tilt switch (ball-bearing type is suitable)

  • 1 x 470 ohm resistor (R_Protect)

  • Breadboarding wire (solid core)

The tilt switch should be added to the RGB LED (as described in the Getting ready section of the Multiplexed color LEDs recipe). The tilt switch is wired as follows:

Tilt switch is connected to GPIO Input (GPIO pin 24) and Gnd (GPIO pin 6)

To reproduce...