Serial Monitor not working in PlatformIO with LOLIN S3 (works in Arduino IDE)

1

When flashing the ESP32-S3 using Arduino IDE , the Serial Monitor works as expected .

However, when flashing the exact same code using PlatformIO , no serial output appears afterward.

My platformio.ini :

[env:lolin_s3]
platform      = espressif32
board         = lolin_s3
framework     = arduino
monitor_port  = /dev/ttyUSB0  
monitor_speed = 115200
build_flags   = -D PIO_FRAMEWORK_ARDUINO_USB_CDC_ON_BOOT=1

Arduino IDE settings:
board: LOLIN S3
port: tty/USB0

the code is:

void setup()
{
  Serial.begin(115200);
  delay(1000);
  Serial.println("Hello from LOLIN S3!");
}

void loop()
{
  Serial.println("Still alive...");
  delay(1000);
}

I’d appreciate any help or suggestions on what might be missing in my PlatformIO setup. Thanks!

2

What? Where does that macro name come from? Is this something ChatGPT hallucinated?

It should be called just ARDUINO_USB_CDC_ON_BOOT.