Okay, I have everything working. The keypad, the webapp, everything.
Now, I'm trying to get all of the hardware to fit in a thin case that I 3D printed. It'll all fit, IF I don't attach the ad2pi to the top of the RPi. I'm guessing the AD2Pi doesn't actually use all 16 of the pins. Which ones does it actually use? The closest information I could find on it were four connections to the Beaglebone Black.
Any insight would be greatly appreciated.