I purchased multiple Arduino Mini Pros and MAX485 TTL boards and now I'm trying to make them communicate together, but the problem is that I need that everyone can send and receive when needed.
I mean, normally, the "Master" request something and then the right "Client" responds. But in my application everyone's master and everyone can send at anytime to anyone. Is there a library, that synchronizes the Read/Write between those Arduinos, so that when one is sending (at anytime) that the other ones won't send, until the transmission of the Arduino who's sending is over?
If there's no library, could I attach one more pin between all Arduinos that act like a PTT switch? When one want to send, it pulls the pin X high and if some other Arduino want to send, it checks for that high pin: If it's high, it will wait. Could that work too? Or maybe this isn't reliable?
Any suggestion or help are highly appreciated.