Warning: Implicit Conversion 

Problem:
Breaks compile with warnings on.

I am seeing the below error during compilation:
Implicit conversion loses integer precision: 'in' to 'uint8_t' (aka 'unsigned char')

Solution:
Verbosely cast to uint8_t
Merge pull request #23 from dmiluski/master

Warning: Implicit Conversion
Merge remote-tracking branch 'upstream/master'