I'm building a cue light system (think traffic lights for theatre, media and entertainment industries) and I need to connect outstations (the traffic lights) to the control station (Arduino).
Each control station consists of one button and two LEDs - so I use 4 wires in total (ground, 2x 5v for LED and a pull up for the button). In selecting a connector I noticed that RJ45 is abundant (especially with EtherCon connectors) and cheap to obtain.
What is the danger, both to my system and to switches and networking gear, of using these cables in my system? With the low voltage DC current within the rating for the cables I'm confident it works great for my system on its own - but what would happen if someone accidentally plugged my base station into a laptop for example, or an outstation into a switch? Can I use certain pins to mitigate this or should I use an entirely different connector all together?