Am I missing something glaringly obvious?
Yes.
If you have nothing connected to a pin that is defined as an input, it floats and returns values picked up by noise.
See this:-
http://www.thebox.myzen.co.uk/Tutorial/Inputs.html
Am I missing something glaringly obvious?
Yes.
If you have nothing connected to a pin that is defined as an input, it floats and returns values picked up by noise.
See this:-
http://www.thebox.myzen.co.uk/Tutorial/Inputs.html