Book Image

GNU/Linux Rapid Embedded Programming

By : Rodolfo Giometti
Book Image

GNU/Linux Rapid Embedded Programming

By: Rodolfo Giometti

Overview of this book

Embedded computers have become very complex in the last few years and developers need to easily manage them by focusing on how to solve a problem without wasting time in finding supported peripherals or learning how to manage them. The main challenge with experienced embedded programmers and engineers is really how long it takes to turn an idea into reality, and we show you exactly how to do it. This book shows how to interact with external environments through specific peripherals used in the industry. We will use the latest Linux kernel release 4.4.x and Debian/Ubuntu distributions (with embedded distributions like OpenWrt and Yocto). The book will present popular boards in the industry that are user-friendly to base the rest of the projects on - BeagleBone Black, SAMA5D3 Xplained, Wandboard and system-on-chip manufacturers. Readers will be able to take their first steps in programming the embedded platforms, using C, Bash, and Python/PHP languages in order to get access to the external peripherals. More about using and programming device driver and accessing the peripherals will be covered to lay a strong foundation. The readers will learn how to read/write data from/to the external environment by using both C programs or a scripting language (Bash/PHP/Python) and how to configure a device driver for a specific hardware. After finishing this book, the readers will be able to gain a good knowledge level and understanding of writing, configuring, and managing drivers, controlling and monitoring applications with the help of efficient/quick programming and will be able to apply these skills into real-world projects.
Table of Contents (26 chapters)
GNU/Linux Rapid Embedded Programming
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

The USB video class device 


A special video class device is represented by the USB video class (UVC) device , which is a USB device class that describes devices capable of streaming videos, such as webcams, digital camcorders, and so on. They are so important and widely used that they deserve a special section in this chapter to present them.

As said earlier, the CPUs used in most embedded systems usually have an internal video interface, but in some circumstances, these interfaces cannot be used. Examples would be when we need not overload the CPU to video related duties or when the CCD sensor is too distance from where the CPU is located and the data communication is difficult because of the parallel bus used. Well, in these cases, we can use a webcam that supports this standard.

The Linux kernel supports this device class in both kernel side (the uvcvideo device driver) and in user space with the uvcdynctrl utility. The driver, if not enabled into the running kernel, can be enabled into...