I don’t know why segmentation fault comes out, but I have managed to make the inclinometer work like this:
1.- I have put the startSDL () and graphics () functions in a program called sdl.c (like the compas application), like: void startSDL () with int graphics ().
2.- I have adjusted the screen variable in current_w-300 and current_h-140 because the raspberry work with a 4 “screen.
3.- Other personal settings (that do not affect).
4.- It only works if you call the program from a terminal after starting the graphic mode with startx.
Jaume