CrossRoads:
Is the DSS Circuits I2C library used with this?
Or is it one or the other?
Do you mean with this chip or with the MultiSerial shield?
Either the standard Wire library or the DSS Circuits library will work with this chip. I use the DSS Circuits library because I need to talk to this chip from inside an interrupt service routine (ISR). The Wire lib uses interrupts, and therefore can not be used inside an ISR. The DSS library does not use interrupts, so it can be used inside an ISR.
I hope I answered the question...