sarouje:
I think I am not getting the issue here.if(Serial1.available()>0)
{
//Serial1 data available
}
will that tell you, the data is coming from Serial1? @Robin's tutorial is a great start to write non blocking serial read. It might seems complex at first but that's the right approach.
I'm sorry. I didnt test the second part I posted, it's getting late here. I was just wondering if something like that could work when keeping in mind that only one device will talk to the Arduino.