Yes that is correct.
Your last question regarding preceeding 0's got me thinking. The way it is currently working isn't very good.
The example of "ABC" could work out to any number of possibilities eg 0x0A, 0x0B, 0x0C, or 0x0A, 0xBC, or 0xAB, 0x0C.
Thank you for getting me thinking about that.
If I require the hex to be input in xx hex format eg 0ABC0D the char array will always have an even length, which should make things a bit easier to translate to the desired and correct output 0x0A 0xBC and 0x0D.
This post is definately going to come in handy Print hex with leading zeroes as my signal RX function does not produce proceeding 0's which is what started this post.