Waking processor with external RTC

All ESP32 boards running MicroPython.
Target audience: MicroPython users with an ESP32 board.
Post Reply
User avatar
liudr
Posts: 140
Joined: Tue Oct 17, 2017 5:18 am

Waking processor with external RTC

Post by liudr » Sat Jul 07, 2018 5:30 am

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.

loboris
Posts: 266
Joined: Fri Oct 02, 2015 6:19 pm

Re: Waking processor with external RTC

Post by loboris » Sat Jul 07, 2018 9:03 am

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

User avatar
liudr
Posts: 140
Joined: Tue Oct 17, 2017 5:18 am

Re: Waking processor with external RTC

Post by liudr » Tue Jul 10, 2018 6:00 pm

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?

Post Reply