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Time taken by ESP-WROOM-32D Module to wakeup from Light Sleep mode
Posted: Thu Feb 01, 2018 8:54 am
by FCT_IOT
Hi,
I would like to know the wakeup time taken by the ESP-WROOM-32D Module to wakeup from light sleep mode. Any links to the reference documents or test carried out will be helpful.
Thanks in advance
Re: Time taken by ESP-WROOM-32D Module to wakeup from Light Sleep mode
Posted: Fri Feb 02, 2018 10:11 am
by FCT_IOT
Ping
Re: Time taken by ESP-WROOM-32D Module to wakeup from Light Sleep mode
Posted: Fri Feb 02, 2018 2:06 pm
by WiFive
It depends on whether you power down the flash and if you do it will be limited by the startup time of the flash chip. Otherwise it should be fast. Maybe someone has a measurement.
Re: Time taken by ESP-WROOM-32D Module to wakeup from Light Sleep mode
Posted: Fri Feb 02, 2018 2:48 pm
by ESP_igrr
From memory, the time it takes to enter/exit sleep mode, without powering down the flash chip, is about 350us (at 240MHz CPU clock).
In addition to that, real sleep time may overshoot the set time by (+1ms +/- 5%), due to the internal RTC clock drift.
When flash is powered down when entering light sleep (this happens if sleep time is over 2.5ms and PSRAM is not used), then the extra time needed to wake up the flash is accounted for, and light sleep time is reduced accordingly.
We're working on improving accuracy of light sleep time in order to support automatic light sleep mode.
Re: Time taken by ESP-WROOM-32D Module to wakeup from Light Sleep mode
Posted: Fri Feb 02, 2018 2:55 pm
by WiFive
ESP_igrr wrote:
When flash is powered down when entering light sleep (this happens if sleep time is over 2.5ms and PSRAM is not used), then the extra time needed to wake up the flash is accounted for, and light sleep time is reduced accordingly.
Nice, but obviously only applicable to timer wakeup source.