Hi huntd69,
Thanks for the advice. Once I verify that the code works as it should, I will be moving everything onto a PCB. I would like to use an embedded Arduino circuit I made in the eventual keyboard device.
At this point, however, I don't yet have any components to solder. I literally just have a commercial Uno with a jumper connected to the input pin at one end, which I then manually plug into a GND pin on the Uno while the code is running. My hope was that I could use this to verify that the button is reading (and thus the USB signals are sending) by looking at whether the LED on pin 13 goes off when the button is grounded out. For some inexplicable reason however, it is freezes every time and as soon as it reads the button once -- since I get exactly one 0 printed out to the serial monitor before nothing else prints...?