Yes, I know that, I'm doing all my pcb's by hand, it's always 1 layer board (I don't need more layers, board size does not matter. See the image below).
I know about USART, but I need max232, which is expensive, and it is more work to do. So I'm going to do something with PIC18F2550 (28 pin device, like Atmega328 in arduino uno) which has USB 2.0 built in, no need for any extra components, except for few passive one's. And it will be easy to built and to communicate with a board.