Newbie: Control relay

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

I have a question. For my proyect I want to controller a board which 8 relay's, and I want to used a Arduino as Master mode and the other three as Slave Mode, these are going to controller the relay's board.

My question is as I can to connect the Master and the Slave to send command, ¿using the pin 1 and 2 (serial comunication)? ¿ICSP? I need the all Arduinos are comunication toghter in the same time, because the Master send a command to active a specific relay on the board.

Thank in advanced.

Regards,
:slight_smile:

2

Using the pin 0 and 1 (serial communication) the answer is no. You have to connect an input to an output and while you can connect many inputs to one output you can't connect outputs together.

How far apart are these going to be? maybe you can use radio or RS485 protocols to link them together.

3

And there are a comercial board for Arduino for RS485 or RS422?

It's near each Arduino, about 9 meters, but I cannot used RF :frowning:

Thank.

4

It's near each Arduino, about 9 meters,

In signalling terms 9 meters is not near.

And there are a comercial board for Arduino for RS485

Yes look for a DMX sheild, this is a sort of multi drop standard that would do what you want.