Hi Omar,

I have used a MAX3223 (or is it MAX2332) to connect multiple µ-controllers to a single host. They have the ability to put the output lines into a hi-z state. The trick is to define your protocol such that only the host can initiate communication, limiting the µ-controllers to responding to the host's query. It would be bad if two or more of the µ-controllers tried to "talk" at the same time. I've discussed this before on this forum. Search on my name, or on RS232 and you should be able to find a more detailed description of what I've done.