ESP32 Forum

Hello,

I would like to know if is possible to wake up ULP by using any RTC gpio with a HW interrupt while ULP is sleeping. Until now, I'm able to wake up the CPU using "esp_sleep_enable_ext1_wakeup" but I'm not sure if is possible to avoid waking up the CPU and go directly to ULP. If it's possible, please let me know how.

Regards,
Pascal.

I don't think it is possible but you may be able to check from ulp program whether the interrupt occurred while it was sleeping and prevent the interrupt from waking the main cpu, not sure.

Is it possible that you could confirm it with your team?

No, waking up the ULP using an IO isn't possible.

ULP can periodically poll the state of the IO, so depending on the expected pulse width you can find suitable polling frequency.

Thanks for the clarification, I believe you should add this information in the ESP32 documentation, is not there and is not that obvious to think it can't.