How to wake ESP32 from hibernation by RTC?

[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

[ESP_Sprite]

Did you already look at the esp-idf deep sleep example included in esp-idf?

[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

[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.)

[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!