FreeRTOS hard real time OR soft real time??

nobody wrote on Tuesday, January 09, 2007:

Is FreeRTOS a hard real time or a soft real time OS?

nobody wrote on Tuesday, January 09, 2007:

That depends totally on your definition of hard real time and soft real time.

By my definition it is hard real time but the terminology is ambiguous so this statement is meaningless :slight_smile:

westmorelandeng wrote on Wednesday, January 10, 2007:


As the previous poster stated - this can be ambiguous in some cases - but let’s use some gross definitions as an example:

Robotic Control On Automotive Assembly Line:
Hard real-time means that if a weld is missed then the system fails. 

Children’s Remote Control Car:
Soft real-time means if the car doesn’t turn in 200ms vs. 300ms - system doesn’t fail.  Not a big deal so to speak.  The action takes place in a reasonable amount of time and isn’t critical.

Can FreeRTOS handle both - my answer to this is yes.  As long as the hardware is capable of hard real-time, I don’t see a reason as to why FreeRTOS couldn’t work.  It may take some adaptation - but a FreeRTOS kernel should work in hard real-time.  Things such as timer tick(s), interrupt latency, real hardware performance, etc. (it’s a long list) have to be examined to see if the system is capable of hard real-time.

John W.