This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
For characters in the ASCII range 0 - 127, the value in a Unicode char is the same as ASCII. You can cast it to a byte or int. For a function to format an int as a hexidecimal or other base string, look at the Integer class static methods. String s = Integer.toHexString( myint ) Bill