hserout[reading] will not display the value of "reading", it will send "reading" as if it was an ascii character. so for example, if reading=37 you will see the character % on your terminal.

You need to use hserout[DEC reading] for it to display the decimal representation of the value of reading.

*edit* also, check to make sure the serial out is working. try hserout["Test"] and see if u get Test on your terminal.