Note, %hu and %hhx are not portable ways to print uint16_t and uint8_t. Instead, you're supposed to #include <inttypes.h> and use: "No type promotion here:

Note, %hu and %hhx are not portable ways to print uint16_t and uint8_t. Instead, you're supposed to #include <inttypes.h> and use: "No type promotion here: %f %"PRIu16" %"PRIx8"\n"