Book Image

Raspberry Pi Robotic Blueprints

Book Image

Raspberry Pi Robotic Blueprints

Overview of this book

The Raspberry Pi is a series of credit card-sized single-board computers developed in the UK by the Raspberry Pi Foundation with the intention of promoting the teaching of basic computer science in schools. The Raspberry Pi is known as a tiny computer built on a single circuit board. It runs a Linux operating system, and has connection ports for various peripherals so that it can be hooked up to sensors, motors, cameras, and more. Raspberry Pi has been hugely popular among hardware hobbyists for various projects, including robotics. This book gives you an insight into implementing several creative projects using the peripherals provided by Raspberry Pi. To start, we’ll walk through the basic robotics concepts that the world of Raspberry Pi offers us, implementing wireless communication to control your robot from a distance. Next, we demonstrate how to build a sensible and a visionary robot, maximizing the use of sensors and step controllers. After that, we focus on building a wheeled robot that can draw and play hockey. To finish with a bang, we’ll build an autonomous hexcopter, that is, a flying robot controlled by Raspberry Pi. By the end of this book, you will be a maestro in applying an array of different technologies to create almost any imaginable robot.
Table of Contents (14 chapters)
Raspberry Pi Robotic Blueprints
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Color finding with OpenCV


Now you'll want to use OpenCV and your webcam to track your puck. OpenCV makes this amazingly simple by providing some high level libraries that can help you. To start with, you'll want to create a basic file that allows you to establish a threshold and then display the pixels as white that exceeds this threshold. To accomplish this, you'll edit a file to look something similar to what is shown in the following screenshot:

Let's look specifically at the code that makes it possible to isolate the colored puck:

  • hue_img = cv.cvtColor(frame, cv.COLOR_BGR2HSV): This line creates a new image and stores it as per the values of Hue (color), Saturation, and Value (HSV) instead of the Red, Green, and Blue (RGB) pixel values of the original image. Converting to this format (HSV) focuses our processing more on the color as opposed to the amount of light hitting it.

  • threshold_img = cv.inRange(hue_img, low_range, high_range): The low_range and high_range parameters determine the...