I'm working with an ELM327 OBD II Interpreter. The serial data is in the form of ASCii, intended to communicate with a PC Serial Port (yea, from a decade ago). If I send Request "01 05" (for Coolant Temp) it has to be in the form of ASCii. The Response would begin "41 05" then the value, all in ASCii. This means the first received byte is the upper nibble of the first Hex character, the second byte the lower nibble, and so forth. The PBP3 Reference Manual lists a HEX Modifier. The example leaves lots of ambiguity as to how it should be used. I am open to any suggestions on how to structure the "unraveling" code.