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

Exchanging data via the CAN bus


In this section, we will see how we can use the CAN bus on our embedded kits using the transceiver-less connection only (in fact, using a transceiver is trivial; we just have to add one without any other software modifications). We'll see how to use both on-chip controllers on an external one connected via SPI to the main CPU.

Using the on-board controller

To do a transceiver-less communication with the on-board controller, we have to use the BeagleBone Black and the SAMA5D3 Xplained boards connected as shown in the following diagram. The circuitry has been realized considering what we said regarding the transceiver-less issues:

Note

The resistor is set as R=100KΩ.

At this point, we have to enable our CAN interfaces as described earlier for both the BeagleBone Black and the SAMA5D3 Xplained. For the first board ,we can set up the interface as shown here:

root@bbb:~# ip link set can0 up type can bitrate 50000
                        loopback off triple-sampling...