Go Down

Topic: Atmega328 like sleep with ESP8266/ESP32 (Read 470 times) previous topic - next topic


Is there a sleep mode in ESP8266/ESP32 like the one in Atmega328?

1)sleep/halt the cpu
2)wakeup with watchdog timer or any hardware timer
3)Resume operation from where the CPU was before sleeping

All I understand is that wakeup on these MCUs resets the CPU which slows the wakeup, all the libraries and peripherals attached need to be re-initialised.

Really, there is no real sleep/resume?

Thanks and Regards,


Jun 25, 2019, 03:47 pm Last Edit: Jun 25, 2019, 03:48 pm by Idahowalker
You do realize that the ESP32 has 3 cores?

Core0, Core1, and ULP (Ultra Low Power). The ULP core has its own RAM and program storage space. Try doing a search on the internet on the words "ESP32 ULP code".

What I tend to do is to read about a device and look over its spec sheet before buying the device.


Jul 06, 2019, 08:59 am Last Edit: Jul 06, 2019, 09:00 am by wonderfuliot
As per this link

light sleep halts the CPU and saves the RAM contents too. Upon wake-up, the CPU resumes from where it left. Current consumption, while not very good, is still quite decent @ 0.79mA during sleep with timer as a wake up source. Can it be used in Arduino loop() ?

Go Up