how to use mcp23017 for more i/o pins

Projects Programming
1

i am using the mcp23017 chip as a port expansion with the Adafruit library

part of of my project is to use some of the other pins not with the chip but with DigitalWrite and/or DigitalRead as we normally do

is it possible ? do i have to use all i/o pins with the mcp Adafruit library ?

2

Surely the idea is that the chip is a port expander and as such provides the ability to provide more input/output pins by using the I2C interface. If that is so then you can use the remaining pins on the Arduino as well as the extra inputs provided by the chip and library.

It would be a pretty useless device if it provided say 16 more inputs but prevented the use of 16 inputs on the Arduino.