Page 1 of 1
Waking processor with external RTC
Posted: Sat Jul 07, 2018 5:30 am
by liudr
I am trying to use a DS3231 to wake ESP32. Is any ESP32 GPIO pin able to wake the processor or are there specific pins that can do that? I read the ESP32 doc and it didn't really cover it. Could anyone point to a good source to read about power modes and how to use micropython to run these modes? Thanks.
Re: Waking processor with external RTC
Posted: Sat Jul 07, 2018 9:03 am
by loboris
GPIOs
0, 2, 4, 12-15, 25-27, 32-39 supports RTC_GPIO function and can be used for wake-up from deep-sleep.
See
ESP32 Pin List
Re: Waking processor with external RTC
Posted: Tue Jul 10, 2018 6:00 pm
by liudr
Thank you Loboris! I happened to have picked GPIO4. After reading the doc you provided, and the list of pins you provided, I now understand that all of these pins belong to VRTC group that can wake the CPU. I would probably have come to the same conclusion with a lot more time and frustration without your pointers.
What about general-purpose interrupts? Are they available on all GPIO pins or just select pin groups?