Hi,
what is the maximum length of cable that I can have between my Arduino and my sensor? I'm looking at using Cat5 to connect the Arduino to my room sensors. I want to create a cluster of sensors which are accompanied with an RJ45 jack, then simply wire it all up using Cat5 through the house.
This is a question it is impossible to answer, and without any real details of what sensor you are using it is impossible to even guess.
At the moment your question is akin to the good old question of "How long is a piece of string?"
Much more information is needed.
What sensors?
How are they wired?
What protocol do they use?
What arduino do you have?
How far away do you want the sensors?
No when we say what sensor we mean the part number so we can see how it transfers the information.
However at only two meters distance you should be fine with most things.