Book Image

Hands-On RTOS with Microcontrollers

By : Brian Amos
Book Image

Hands-On RTOS with Microcontrollers

By: Brian Amos

Overview of this book

A real-time operating system (RTOS) is used to develop systems that respond to events within strict timelines. Real-time embedded systems have applications in various industries, from automotive and aerospace through to laboratory test equipment and consumer electronics. These systems provide consistent and reliable timing and are designed to run without intervention for years. This microcontrollers book starts by introducing you to the concept of RTOS and compares some other alternative methods for achieving real-time performance. Once you've understood the fundamentals, such as tasks, queues, mutexes, and semaphores, you'll learn what to look for when selecting a microcontroller and development environment. By working through examples that use an STM32F7 Nucleo board, the STM32CubeIDE, and SEGGER debug tools, including SEGGER J-Link, Ozone, and SystemView, you'll gain an understanding of preemptive scheduling policies and task communication. The book will then help you develop highly efficient low-level drivers and analyze their real-time performance and CPU utilization. Finally, you'll cover tips for troubleshooting and be able to take your new-found skills to the next level. By the end of this book, you'll have built on your embedded system skills and will be able to create real-time systems using microcontrollers and FreeRTOS.
Table of Contents (24 chapters)
Section 1: Introduction and RTOS Concepts
Section 2: Toolchain Setup
Section 3: RTOS Application Examples
Section 4: Advanced RTOS Techniques

Understanding RTOS Tasks

The super loop programming paradigm is typically one of the first programming methods that an embedded systems engineer will encounter. A program implemented with a super loop has a single top-level loop that cycles through the various functions the system needs to perform. These simple while loops are easy to create and understand (when they are small). In FreeRTOS, tasks are very similar to super loops – the main difference is that the system can have more than one task, but only one super loop.

In this chapter, we will take a closer look at super loops and different ways of achieving a degree of parallelism with them. After that, a comparison between super loops and tasks will be made and a theoretical way of thinking about task execution will be introduced. Finally, we'll take a look at how tasks are actually executed with an RTOS kernel...