Process 

I initially tried to put together all the code and circuit at once. It didn't work, and was not immediately clear what was going wrong even after some debugging (turns out I just forgot to connect my potentiometer to power). I scaled back to the basic pushbutton-LED demo code, then added back the potentiometer code and finally realized my wiring issue.

I wanted to play with exposing a Particle function, and initially forgot to return an int. I also realized it sometimes takes a few refreshes to show up on the console.