An Operating System on a $4 Board? | Getting Started with FreeRTOS on the Raspberry Pi Pico

In this video, we talk about the basic concepts of a Real Time Operating System, or RTOS. Also, we go into how to setup a CMake project for the Raspberry Pi Pico to get FreeRTOS on the device. Finally, we discuss how to setup two tasks to blink LED's at different intervals.

Without an operating system on your Raspberry Pi Pico RP2040, making programs that execute multiple functions at the same time is extremely difficult. By using an RTOS, you're able to write code in terms of "tasks" that a scheduler runs based on their priority. FreeRTOS is an open source RTOS that allows you to make your Pi Pico projects more powerful.

🏫 COURSES 🏫

Chapters:
0:00 Intro
0:33 FreeRTOS
2:05 Coding
6:30 Demo
6:45 Multitasking
7:20 Outro

[LowLevelTV]

GUYS! I FIXED MY PICO AND THE EXAMPLE!

Inside the task code, I forgot to put the tasks in an infinite loop. Because of this, the blink only executes once, and the board appears as though its crashing. I made both of those tasks infinite loops and the board came back to life (was never dead xd) and behaved as expected.

Thanks to @max from Discord for finding this bug

[akashpatil]

Man, your vids are really great and helpful! Please just don't stop uploading!!! <3

[raresharktooth]

i've done a bit of RTOS on older PICs. Now returning to the concept for some robotics. I hope you will cover what might be possible with FreeRTOS on one core and more linear C code on the other core of the pico. Also, i am really liking the OpenOCD/swd/GDB setup with rpi pico, pretty much the best debug capabilities i've ever had. However, i remember having very difficult time debugging RTOS code in earlier days. Hope you can cover some practical RTOS debugging with GDB and dual core. Thanks for video!!

[cprogrck]

The rp2040 on the pi pico has PIO's that can do this. They're like independent cores that manage gpio pins for you. Using the PIO assembly code you can implement just about any protocol. In this case one PIO to blink the LEDs in sync with the clock, maybe add an interupt for the button. Then one PIO for the serial bus. Any pin can go with any PIO (kinda). You can then do what you need to inside of your main program loop and not worry about timing. The rp2040 is neat.

[junaidpv]

Frying a dev board is one of most hated experiences for me in the electronics field! Thanks for the tutorial.

[liquid]

Great stuff, I’m super interested in freeRTOS and love all the pico videos, thanks!

[LowLevelTV]

Any cool projects using FreeRTOS? Do tell ;)

[lighthunt]

@Low Level Learning, Awesome Thank you.
A suggestion: Allegedly, there is now Symmetric Multiprocessing Branch of FreeRTOS available for RP2040 (=RTOS on both cores), would be nice to show how to enable it ...

[Cptnbond]

Nice, a short and sweet tutorial -- will take some time to absorb ;-)

[d]

Great! Exactly what I was looking for!

[hobbes]

2:25 shouldn't this be the smp branch that we need to clone.. as per the docs it's the smp branch which is intended for pico

[fred.chapman]

Thanks for the FreeRTOS tutorial! Can you please post a follow-up video showing the results on the Pico? We need closure. 😁

[Cyrusradplus]

Hi there is a big question in me about Freertos!
Imaging if we have 3 functions and compiler needs to run every function in 1us so all functions needs 3us to run
Can Freertos do all of these 3 functions just in 1us and same time?

[DevvratYadav]

Can we make Gateway using RPi Pico, FreeRTOS, Node-Red ?

[paul]

Could you make a video about working with MicroPython in VS Code with the Raspberry Pi Pico?

[heel]

great video. Do you know if the two tasks run on separate cores and how to enforce this?

[markday]

I didn't see any configuration changes to indicate multiple cores (which may also need some RP2040-specific code for communicating between cores). I'm guessing this is all running on a single core.

[yubrajbhoi]

How are you rebooting the pico into programing mode? It doesn't look like you are pulling out the plug every time. Are you using a reset button?

[rahulkushwaha]

nice intro, please bring more tutorials on freeRTOS.

[AlexShynkarenko]

any way to have a raspberry pi to act as a storage device and run a program?