connect to a USB host over serial arduino

serial_slave.cpp

uint8_t counter;

void setup() {

  Serial.begin(115200);
  SerialUSB.begin(115200); // speed is irrelevant for native port
  counter = 0;
  
}

byte lat;

void loop() {

  Serial.print("Programming port. Counter is at ");
  Serial.println( counter);

 // SerialUSB.print("Native port. Counter is at ");
  //SerialUSB.println( counter);
  
  while(SerialUSB.peek()!=-1)  
  {
    lat = SerialUSB.read();
    SerialUSB.print("new byte is:");
    SerialUSB.println(lat);
  }
  

  //counter++;
  delay(500);
}