Compiler can choose inappropriate println version in such cases, with the unsigned long parameter in your case
Actually it was a signed long. When I printed it without the HEX specifier it printed as a negative number.
If the type for x is byte I expect the above to print out eight characters, 00110011.
Is it possible to implement Serial.printf() as C language's printf() does ?If so, we use %d for integer, %s for string, %f for float point data, etc.We can print different data type in the same function call.We also can print many data in the same code line..