Serial number from ATMega4809 processor

Projects Programming
2

If you want to avoid the use of String:

  char test[21];
  sprintf(test,
          "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
          SIGROW.SERNUM0,
          SIGROW.SERNUM1,
          SIGROW.SERNUM2,
          SIGROW.SERNUM3,
          SIGROW.SERNUM4,
          SIGROW.SERNUM5,
          SIGROW.SERNUM6,
          SIGROW.SERNUM7,
          SIGROW.SERNUM8,
          SIGROW.SERNUM9
         );
  Serial.println(test);

If you just need the hex value, without converting to a char array:

  byte testarray[10];

  memcpy(testarray, (void*)&SIGROW.SERNUM0, sizeof(testarray));

  for (size_t i = 0; i < sizeof(testarray); i++) {
    if (testarray[i] < 0x10)
      Serial.print('0');
    Serial.print(testarray[i], HEX);
  }
  Serial.println();