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How to wake ESP32 from hibernation by RTC?

Posted: Wed Feb 17, 2021 2:23 pm
by janbenes
Hello, I have not found any documentation on this. Can someone please share example how to properly configure hibernation and rtc in order to wake ESP32 by the rtc?

Thank you, Jan

Re: How to wake ESP32 from hibernation by RTC?

Posted: Thu Feb 18, 2021 1:34 am
by ESP_Sprite
Did you already look at the esp-idf deep sleep example included in esp-idf?

Re: How to wake ESP32 from hibernation by RTC?

Posted: Fri Feb 26, 2021 12:32 pm
by janbenes
Hello, thank you. I am aware of deep sleep and I use it. The question is how to wake by RTC from hibernation. Hibernation is not deep sleep. Jan

Re: How to wake ESP32 from hibernation by RTC?

Posted: Mon Mar 01, 2021 2:59 am
by ESP_Sprite
You mean 'hibernate mode' as discussed here?. From what I remember, the ESP automatically goes into hibernate mode if you do not configure the ULP to run and do not define RTC memory contents. (I got confused because 'hibernate mode' is not a term Espressif uses in ESP-IDF; there's just 'deep sleep' with various power domains enabled or disabled.)

Re: How to wake ESP32 from hibernation by RTC?

Posted: Mon Mar 01, 2021 8:34 am
by janbenes
Thank you. So if no ULP and RTC memory is defined, the chip should take about 2.5µA and still be able to wake-up by timer or GPIO interrupt. Interesting, I will try that. Thank you!