I finally got the example from this addon to compile - I had to add the ofxHIDapi addon to get it working - and it recognises all the HID devices and prints them in the console, including the USB gamepad I am trying to use.
I’ve tested the gamepad with MaxMSP and all the buttons respond.
If anyone can have a look at the included example and get me started, that would be great, because I’m at a loss.
Basically, I am just trying to trigger different actions when the buttons on the controller are pressed - for now just getting it to print “button 1 pressed” would get me on my way. I’m on OS X 10.13.