I'm completely new to Arduino, but diving in head first. I presently have multiple isolated control boxes of timers and relays controlling a number of things around my home and hobby farm such as outdoor lighting at dusk, automatic feeding of horses 4 times a day, exhaust fans, opening and closing windows in the barn depending on temp and humidity. Well I think it's time I consolidated all these isolated devices into one controller and get with the times...... My first question is the operating distance a relay module can safely operate over 22 ga twisted pair wire. As I am bringing everything back to a central point in my home, my analog experience tells me to calculate voltage drop. I can remotely power each relay board, but the high/low digital signal is where I get lost. I don't know the current, and not sure if it's even relative with a digital signal. So...... I would appreciate any knowledge you can share with me regarding the maximum distance over 22ga twisted pair you can safely operate a relay module. I have one location of a pump, that is 900m away, will it work??? Can this be compared to DSL internet where the modem can be 7 or 8 km's from the exchange equipment and the digital signal is fine???
Love to hear your comments on this and any experience you've had.