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 video tools


Even if using the sysfs interface to manage video devices in a more efficient manner, we can use a dedicated tool set named v4l-utils in the package by the same name, which can be installed as usual into the system if it is missing.

The main program in the package is v4l2-ctl that can be used to get a lot of information regarding a video device. Just to show the power of this command, let's try to explore all capabilities of a video device assuming we know about nothing of it. First of all, we can detect connected video devices using the --list-devices option argument as shown here:

root@bbb:~# v4l2-ctl --list-devices 
USB 2.0 Camera (usb-musb-hdrc.1.auto-1): 
   /dev/video0 
   /dev/video1

Then, we have discovered that our device has been composed of two video devices mapped into the system with the /dev/video0 and /dev/video1 files. Then, we can get some information regarding the device driver we're currently using to manage this device. This can be done using...