V2.0.15 USB OTG Serial.println() works WITHOUT a Serial.begin()

[def1149]

Board

Adafruit Feather ESP32-S2

Device Description

N/A

Hardware Configuration

N/A

Version

latest master (checkout manually)

IDE Name

Arduino IDE 2.3.2

Operating System

Windows 10

Flash frequency

80 Mhz

PSRAM enabled

yes

Upload speed

921600

Description

Serial.print() works WITHOUT a Serial.open()

Sketch

void setup() {
  // put your setup code here, to run once:
}

void loop() {
  Serial.println("\nThis Prints !!??");
  delay(2000);
}

Debug Message

N/A

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[SuGlider]

@def1149 - Adafruit Feather ESP32-S2 uses Native USB CDC to print using the Serial object from Arduino.
It has no UART<->USB chip, therefore its USB port is directly connected to the S2 USB pins.

Indeed, Serial.println("\nThis Prints !!??") works because USBCDC::begin() is called in the Arduino Initialization, before the sketch starts in app_main().

I think that there is a reason for that, maybe related to being able to print Debug messages before the Sketch starts, if necessary.

[SuGlider]

@me-no-dev - The call to Serial.begin() in main.cpp->void app_main() started with #5422 followed by #5466 and then finally in #6341

In #5422 there is the commit d425a3f that says "USB CDC should also be started in main".
Is it still valid? Do you remember the reason for that?

[me-no-dev]

@SuGlider sorry, I did not understand this is USB. It would then make sense that it's ON

[Parsaabasi]

Hello,

Due to the overwhelming volume of issues currently being addressed, we have decided to close the previously received tickets. If you still require assistance or if the issue persists, please don't hesitate to reopen the ticket.

Thanks.

[SuGlider]

This shall be investigated.