RTC module DS3231 timer based wake-up of ESP8266, nodeMCU, arduino

Описание

This video shows how to wake up #ESP8266 from deep sleep using an square wave interrupt from #RTCtimer module #DS3231.
We can go for a sleep forever and use low pulse from SQW pin to reset ESP8266, nodeMCU, ESP12 etc at a particular time.

code here:
https://github.com/iambappa/Embedded-C/blob/master/RTC-time_based-wake_up

circuit:
DS3231 ---- ESP8266
VCC ----- 3v3
GND ---- GND
SDA ----- 4
SCL ----- 5
SQW ---- LED ---- 100R ---- GND
|____104C ---- GND (optional)
|____ RST