It's possible I screwed up on the purchase of the mcp23017 but I wanted to use it to connect the TMP36 analog sensor and a photocell to it.
I followed these instructions for the TMP36
and connected it to GPA1 input.
I don't want to use the pullup or pull down functions of the mcp23017 for this one unless I need to. So I have no idea on how to code the pi (or wire) an input that would work.
As for the photocell these instructions suggest
you need a voltage divider with a pullup resistor. I didn't have one so just used a 10k resister in the voltage divider as per these arduino instructions.
Itis connected to GPA2
In any case any hints as to how to write some code to get basic input with no pullup-resistors from the pins would be nice. I've done a search on the forums and it seems most of the uses are to have switches trigger some event which makes me believe my sensors would not work with this chipset.
I apologize for my ignorance if the info is easily accessible and i missed it.