two connected Arduinos

I want to have one master Arduino with just buttons/switches sending commands to a slave Arduino with relays. The Arduinos are connected though wire reaching a distance of 300ft apart.

what is the most cost effective way to do this ?

Thankyou for your time.

RS422, probably...

Earlier i was looking at

Or RS-485, same horse different color.


Shane Sounds similar to what I was planning. I agree that RS422/485 is the easiest connection method, which allows long distance and reasonably high speeds, over dodgy cable. You will need to watch that both legs are balanced relative to earth though.

I'm interested if you have done the code, or settled on a protocol yet.

Thanks Mark

I have used RS422 to control a ROV using the Futurelec boards.
I can recomend this method as the cable is sometimes close to electric motors or other noises.