Introduction to RTOS Part 1 - What is a Real-Time Operating System (RTOS)? | Digi-Key Electronics

An RTOS is often a lightweight operating system (OS) designed to run 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 need to run several threads at the same time 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 not needed. 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 they 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.

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[OdotRIHKRC]

Without the help of Shawn many in the community would be lost. Thanks tons Shawn for all you do.

[MattKremer]

This is exactly the informational/tutorial series I've been looking for. Even better I found it after it's all done, so I can go straight through it! Thanks!

[超伝導ゼロス]

Thank you, Dr. Digi-Key.
In real time, the narration is displayed in text in the right window of the video. This feature is very useful for me, who has never spoken English.

[saganasimov]

This video series is a goldmine for me, as I want to pursue embedded systems. Thank you very much for this and more videos to come such as this.

[bryanst.martin]

I remember 2 decades back when I got a little catalog from them. Only the size of a Readers Digest condensed book, for those that remember those. Now they sit prominently and honorably on the World stage, with a catalog too big to ship, and CS reputation unmatched in my history. Keep it up!

[tingoyeh]

Great video. Other tutorial online are either too hard or too basic, this series of video just match the hole in this field.

[akulanvn]

You explained it so perfectly. I was having such hard time understanding RTOS in my embedded systems class this helps incredibly. Thank you for being so informative.

[finnyphilipbiju]

Thanks for coming up with this tutorial. Was really waiting to explore more on RTOS

[kenwallace]

This intro is as good as any I've seen, especially relevant for deciding if the complexity of RTOS is warranted. In my case, it's not but I feel better sticking with the super loop.

[gaminggoneviral]

Yes!!! Edge Ai and now RTOS!! Love your stuff! please dont stop Sir! These things are actually the next biggest trends. Thanks Sir.

[mattnielsen]

This series is a godsend. Excited for the upcoming tutorialsm

[EarlWallaceNYC]

I've been looking for Shawn. since he left "that other maker site". I like Shawn's style, and his teaching style works for me. He and Digi-key get my vote and more of my business.

[veralagarwal]

Yeahhh!!.. After learning RTOS in books and Online resources, I got the best from Shawn.

[TheMateusrex]

Just starting a career in embedded systems, and I'm looking forward to your tutorials. I like your style.

[rickpontificates]

As a game programmer for 30 years, when I learned iOS Swift, I had to change my way of thinking about code because Swift doesn’t function like other languages I’ve used. In Swift, there is NO “main loop”. In fact, the Apple device’s OS is the main loop of your app. Everything in your app is accessed by interrupt handling, either a timer interrupt or a human interrupt, like a button push.

[jerrywatson]

It's the bowtie that keeps me glued. LOL. Thanks for adding a bit of levity to this talk.

[dani_dupae]

Excellent video! I've been watching these trynna learn more for my microprocessors class.

[abuk]

Amazing video, now it is clear to me why is RTOS beneficial!

[tonyfremont]

Glad to see you back at it. I watched all your Arduino videos today, and I've seen all your STM32 videos as well. This is awesome content, and I can't wait for the next video in this series.

[jzero]

7:40 To be fair, an ESP32 is much cheaper than an Arduino, and has BT/WiFi so I tend to use them even for projects they are wildly overpowered for. Super loops are great for simple projects just due to the law of fewer moving parts. Faster to develop, lower surface area for bugs. Project complexity is the primary deciding factor.

Most industrial automation, for example, runs on PLCs, and they are almost universally super loop architectures. Huge scale, loads of I/O, long programs, but still low complexity.

Excellent summary, in any case.