[Max Lobovsky]

What does "the simplest code" mean? If you just want some joysticks and buttons directly mapped to pwms/relays and don't have any autonomous code, there is a significant amount you can remove from the default code. There are several functions you can remove from user_routines.c/h. Removing printf_lib.c/h and any calls to it would be another very significant space saver. There is probably more in other files, look for yourself.