While the Arduino family of boards connect to your computer using a USB virtual serial port, the ATmega ones have an actual serial connection on-board.

Here’s the code we promised you in the current issue of Macworld. To download a Zip archive containing this code as well as the compiled script, click here. long MINUTES = 15; // take a break ...

After some research, it was determined that it would be relatively simple to have an Arduino convert incoming serial data into a parallel output to the printer.