Page 1 of 1

Deep sleep vs Light sleep

Posted: Tue Apr 17, 2018 2:37 pm
by avdalimov14
Hello Folks!

Me and my team are about do some serious power management optimization and we are wondering...:

What is ligth sleep mode differ from deep sleep mode?
We read esp-idf docs and found that they share same wake-up sources, even on both the ULP Co-Processor may run when entering sleep mode.

We found two differences:
1. Current consumption (derivative from powered on peripherals)
2. when going back from Light Sleep Mode, peripherals and CPUs resume operation, their internal state is preserved ( I didn't confirmed it but it is written on esp-idf docs)

Thanks for help!!

Albert

Re: Deep sleep vs Light sleep

Posted: Tue Apr 17, 2018 5:45 pm
by hassan789
Hi.

Deep sleep
--almost all clocks are off
--RTC domain can be kept powered (can save 8kB into ram)
--waking from deep sleep causes a reset
--chip should consume in the uA range

Light Sleep
--Processor core is stopped, but can resume from same location in code (full ram retention)
--if modem is off, the chip should consume <1mA

There is also Modem Sleep if you are doing wifi.

The holy grail for the esp32 is Light-Sleep + Modem Sleep DTIM3 while associated to Wifi. The ESP team is working towards that goal, I believe.

You should read these fully:
https://github.com/espressif/esp-idf/bl ... _modes.rst
https://github.com/espressif/esp-idf/bl ... gement.rst
https://github.com/espressif/esp-idf/bl ... p-stub.rst