Thanks for your explanation Sara. I hadn’t properly understood the distinction between timer and hardware interrupts. I confess I didn’t really understand what you meant by a “regular” function at first, but having dug a little deeper since reading your reply I now realise that timers run under a timer daemon which is a standard task (albeit with priority (config_MAX_PRIORITIES – 1) i.e. the highest possible) and are therefore managed by the RTOS scheduler. In contrast, hardware ISRs can’t be pre-empted under any circumstances.
Thanks again and also for for the many other RandomNerd tutorials which (unlike some of other stuff out there) are clear and accurate.
Robin

Hi.
I’m not sure if I can explain this clearly.
But, basically, FreeRTOS timers are time-based and not executed in a “real” interrupt context. They are basically “regular” functions that run after a timer runs out.
The hardware interrupts are like “real” CPU interrupts. The ISRs must be placed in the internal IRAM, so that the board doesn’t crash in case the flash memory is not accessible at the moment the interrupt occurs.

Regards,
Sara

Hi.
I haven’t played with the settings of the config file, so I can’t tell.
I think you can modify those parameters without issues, as long as you adjust with realistic values. But, you’ll have to try to find out.

Regards,
Sara

Is that possible that we can modify the FreeRTOSConfig.h file in order to adapte it to our needs, without braking anything? And if so, where do we put it? In our sketch directory?

For example, out of the box the framework only allows to have 10 timers, maybe this number is good enough for many applications:

// original:
#define CONFIG_FREERTOS_TIMER_QUEUE_LENGTH 10

But suppose that I need to use 20:

// mine:
#define CONFIG_FREERTOS_TIMER_QUEUE_LENGTH 20

Another example is the length for the task’s name:

#define CONFIG_FREERTOS_MAX_TASK_NAME_LEN 16

What if I need (or want) the length’s name to be 80?

How dangerous is to modify such file in this kind of scenarios?

It’s worth to mention that you don’t need to reserve 10 KBytes of RAM to blink a LED (even for the examples):

#define CONFIG_FREERTOS_IDLE_TASK_STACKSIZE 1024

Greetings!

Hopefully you may have some examples soon.

Thank you!

Hi.
No.
We don’t have any examples for Watchdog timers at the moment.
Regards,
Sara

Hi.
Yes. You can create more than two timers.
Regards,
Sara