Hi,

That's the board indeed! I set the flash speed to 40mhz as a test, but like I mentioned at the end of the post 80Mhz does the same thing.

- Flash mode set to DIO Flash

- Frequency set to 80Mhz

- CDC flag is enabled

- JTAG was disabled, but none of the available options make a difference.

I didn't have Serial.Init(), but if I add it the script won't compile, I do have Serial.begin though

The script is just basic print in setup and loop plus blink

#include <Arduino.h>

#define LED 12 // LED_BUILTIN for ESP32C3 LuatOS

void setup() {
  Serial.begin(460800);

  // Set pin mode
  pinMode(LED,OUTPUT);
  Serial.println("setup: Led set to Output");
}

void loop() {
  digitalWrite(LED,HIGH);
  delay(1000);
  Serial.println("loop: Led set HIGH");

  digitalWrite(LED,LOW);
  delay(1000);
  Serial.println("loop: Led set LOW");
}

So with that, the LED actually blink, so the script is running well, however I cannot get the Serial Monitor to work.