you can remove the hello world statement.
what code does is, when you open the port and send first string it sends back to host and afterwords it enter into the command transmitting loop.
in Linux you can install screen and try to send any char it will send back.
i hope it works, let me know if you have any question.+
Regards,
himanshu
Any one faced this issue? Whats the cause?
Thanks
Rishit