When using Analog or Digital In/Out on any of the available pins on the board, the LCD screen shows corruption and artifacts. In addition, there is unusually high noise when reading Digital or Analog level from any pin (e.g. 1's instead of 0's, 0.99's instead of ~0).
An example screenshot of this behavior is shown below. The screen is supposed to read two lines: KP_TEST, followed by a hex number of bitmask with the pressed buttons. There's 16 buttons and only one button is pressed in the example so we should only see 7 zeros and one 1, 2, 4, or 8, but I'm seeing some F's.
I apologize if this matches an existing post.
Thanks everyone for your help.
I can post test code if needed.