RTOS support for Arduino UNO.

Other Hardware 3rd Party Boards
1

Hello,

I was thinking about doing an RTOS project in Arduino UNO. But, I have read that is not wise to try RTOS in UNO due to low RAM and ROM. If so, what about mega? Can I try RTOS on Arduino Mega? Can anybody suggest RTOS port for Arduino UNO/Mega?

Thank You

2

I used uMT, a very well behaved RTOS, with a Due. Works great and is a good introduction to using freeRTOS on the ESP32.

I thought about using uMT on a Mega but the author lists a few reasons why not, even though uMT does work on a Mega. The overhead of a freeRTOS on a Mega is not worth it. Instead, for the Mega, use a task scheduler.

freeRTOS is native to the ESP32.

3

I'm sorry for the noob question but what is the difference with RTOS over the "standard"
setup() loop() function that we all know?

4

The AVRs in general have a unfortunate ratio of "context" (37 bytes - 32 registers, SP, PC, and SR) to RAM (8k in a MEGA, 2k in an Uno.) Add to that the need for some stack space for each process, and you notice that while you might be able to write a "demonstration" RTOS, it's not likely to be very useful for doing anything. :frowning: