Thanks for your reply:
The constrain is there to avoid a "strange" value that might be send (the goal is of this is to control a toy chopper). I read that this might be wise to do in case a strange value occurs.
The part for the LCD is not used (its between the /* and */) I got rid of it.
The array I changed because I thought it had something to do with my problem, its changed back to 2.
- also got rid of the semicolon, not sure how that got there. Should it be a while statement?
Still no results: I just get a printed "Setup done!" from my receiver.