Albert94:
The LED should be on for a 1 and off for a 0.
So part of your message is 1111001000000 in binary. What exactly does that look like on the LED? I can't see anything in your code that's doing anything with individual bits in a message.
Albert94:
The pc on the receiver side should be able to receive the message.
What program in the PC is receiving the message and what is it doing with it? Which part of that code is sending "Hello world" to the PC? Or do you intend that all of the text sent using Serial will flash the LED according to it's binary representation?
Steve