lrc: uses the ASCII code of each character (uses the value 0x30 for the character '0', 0x31 for '1', etc) which I understand is how most checksums are implemented.
hexlrc: group hexadecimal characters in pairs and interpret the pair as a hexadecimal number. Examples: '12' gets converted to 0x12 and 'A5' to 0xA5.
I've created two LRC checksum functions:
Thanks @ljsSally for the piece of code.