ESP32 delay required after Serial.begin

[michael_x]

@Deva_Rishi

It must have something to do with the ESPtool not releasing the port on time

The USB COM port has to be released by the uploading ESPtool and can then be opened by the SerialMonitor again. That's how I understand @kenb4's response #5.

So, for quick tests where everything happens in setup() and is intended to run just once after an upload, I simply add the delay(400);
BTW: this delay can run before Serial.begin as well.

For real sketches where a quick start after reset is interesting, I know to see the full story only after using the RESET button.

Thanks for the discussion to all.