Introduction to RTOS – 101

A real-time operating system (RTOS) is an operating system that runs multi-threaded applications and can meet real-time deadlines.

An RTOS is often a lightweight operating system (OS) that runs on microcontrollers. Much like general-purpose operating systems, they offer a scheduler to run multiple threads or tasks, resource management (such as file I/O), and device drivers. An RTOS is necessary when embedded engineers must run several threads simultaneously on a processor.  

The “real-time” part of an RTOS means that such software can meet real-time deadlines. Note that this does not mean “fast,” but rather, it can guarantee that task execution time can be calculated prior to runtime.

Embedded programmers often use a “bare-metal” or “super loop” structure instead of an RTOS when concurrency is unnecessary. This is the familiar “setup” and “loop forever” style of embedded code where no OS is employed. Many embedded applications can be written in this format and are often easier to debug. 

In the rest of the series, we will cover various RTOS concepts and provide demonstrations on the ESP32 using Arduino. After each video, excluding this one, we will issue a challenge, and the solution can be found in a Maker.IO link provided in the video’s description. We encourage you to try the challenge without looking at the solution.