The string at the top with the word "char" in it is not the key to his
solution. Any string on top will work, the type cast is just using the
data type (string). The key to John's solution is setting the data
type of the input correctly. The data type of the value being cast in
John's solution is U8, which matches the size of two hex digits (i.e.
42 hex or 66 decimal), hence the code knows to convert one numeric
byte to a one character string. If you were converting a 4 hex digit
number (e.g. 0042 hex), you would need to ensure the data type of the
input was set to U16.
