AVR-Chat

Hi everyone,

I am new to here and this is my first post. And I am totally new to
circuitry.

I only had experience of sending and receiving data between a computer
and a microcontroller. I want to learn how 2 atmel microcontrollers
communicate. The scenario is like this:

A microcontroller is connected to my PC, when another microcotroller
is connected to the 1st one, it can be powered and send its id to the
computer. Later on, I want to have multiple microcontrollers and my PC
should be able to figure out the topology.

Many thanks,
Yingdan