ESP32 Forum

and for poweroff conditions i'm willing to put an extra button cell or any supply to keep my rtc ticking on.

That part is not going to be supported for a while, sorry. If you need RTC to work from backup battery you will need to use a separate RTC chip. ESP32's RTC can work in power-on and deep sleep modes, but power still needs to be supplied.

thanks a lot ESP_igrr,

your one line reply has saved loads of efforts of mine which could be redirected, now, to your suggested alternative of using external RTC.

and for poweroff conditions i'm willing to put an extra button cell or any supply to keep my rtc ticking on.

That part is not going to be supported for a while, sorry. If you need RTC to work from backup battery you will need to use a separate RTC chip. ESP32's RTC can work in power-on and deep sleep modes, but power still needs to be supplied.

Hi,

Actually I and Rajkumar are working together into ESP32 projects and we are validating some of interfaces in which we are in process to validate RTC Interface on ESP32 Chip and also we have one requirement in which device should have updated time after starting device even though device is not connected with any router.

So, I have looked some of portion of RTC memory and timer configurations and found that RTC is powered up in all configurations mode like Active, Modem-Sleep, Light-Sleep and Deep-Sleep mode except Hibernate Mode.

I have worked into some other embedded board based projects in which both Internal and External RTC have been supported into Hardware Itself. So, As per current functionalities and configurations of RTC into ESP32, We can say that it supports only internal RTC but not external RTC.

So, Do you have any plan to support external RTC or is there any way to get support of external RTC into ESP32? or compulsory need to external RTC based circuitry to keep time active in powered off mode as well.

Let me know your feedback or suggestions for this.

RTC is powered up in all configurations mode like Active, Modem-Sleep, Light-Sleep and Deep-Sleep mode except Hibernate Mode.

RTC timer is powered up in "hibernate mode" as well.

or is there any way to get support of external RTC into ESP32?

If by an "external RTC" you mean an RTC chip/module with an I2C/SPI interface, you can use ESP-IDF I2C/SPI drivers to communicate with an external RTC. The specific protocol would likely depend on the RTC chip, and that is something you would need to implement.

RTC is powered up in all configurations mode like Active, Modem-Sleep, Light-Sleep and Deep-Sleep mode except Hibernate Mode.

RTC timer is powered up in "hibernate mode" as well.

or is there any way to get support of external RTC into ESP32?

If by an "external RTC" you mean an RTC chip/module with an I2C/SPI interface, you can use ESP-IDF I2C/SPI drivers to communicate with an external RTC. The specific protocol would likely depend on the RTC chip, and that is something you would need to implement.

Hi,

I have checked power mode table into ESP32 data sheet and found RTC Power Mode off into Hibernation Mode.

Is there any plan to give support of External RTC into existing ESP32 chip itself?

The datasheet says that RTC peripherals are powered down in hibernation mode. RTC controller is always powered up, and it includes RTC timer and one of the two GPIO wakeup sources (ext1).

Regarding external RTC chip support, no we don't have plans for adding such drivers to ESP-IDF.

The datasheet says that RTC peripherals are powered down in hibernation mode. RTC controller is always powered up, and it includes RTC timer and one of the two GPIO wakeup sources (ext1).

Regarding external RTC chip support, no we don't have plans for adding such drivers to ESP-IDF.

Thanks for update.

Hi guys,
how is it going now in 2018?
Is any arduino sketch example available for internal RTC use?
I'd like to reduce consumption of my ESP32-based device, making it alive just a few seconds a day, just to log the temperature.

Hi guys,
how is it going now in 2018?
Is any arduino sketch example available for internal RTC use?
I'd like to reduce consumption of my ESP32-based device, making it alive just a few seconds a day, just to log the temperature.

I share the same concern.
AFAIK the ESP32 SimpleTime example is using ESP32 libraries and should make usage of the buit in RTC.
Am I right?

I would be deeply thankful if I could get a code example of waking up from deep sleep and detecting that the internal RTC is running, so avoiding a power-hungry new NTP sync.

Thank you, experts here, for your kind help.