@ JussiH
I've read at the Viacopter Homepage, that a new Ver. 1.2 N4 Board is released with the following new feature:
--> New version 1.2 N4 expander board - can use UART without turning off BT module
Is it possible, to modify existing Ver. 1.1 Board's on my own?
Did you also modify the uSD Card Slot?