ESP32-S2-DevKit-Lipo-USB RTC not working

Started by findmyname, June 11, 2021, 03:26:27 pm

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The reason for the example not working was the " monitor" command. If findmyname was using it, it is reason for his/hers problem too.
This command outputs the serial log entries. But it has the side effect that when it detects the device after not detecting it (i.e. after deep sleep), it resets the device. And since this happens on the case of waking up from deep sleep, no serial output will reach the terminal and all logs printing the values from RTC are vanished. Then, after the reset, all RTC are on default values.
This does not happen with Espressif HW. The difference is that Espressif HW has a separate USB chip and Olimex (in my HW case) is using CDC USB from the module. I do not know exactly why it behaves differently but probably is not compatible with CDC USB or with separate USB chip it somehow detects the rise from deep sleep and does not need to reset.
I found this out by adding led output for different cases and leaving out the monitor. It works fine without monitor but starting monitor makes it fail.
Some other terminal should be used to show the log. the screen command in Linux does not work well since it terminates when port is not available.


Interesting find, and thank you for the update. Unfortunately, yes a lot of the tools are lagging behind when it comes to the native USB of ESP32-S2.
Technical support and documentation manager at Olimex