Kevin has a good point.
Although calling CAL_Update() from the fast loop (via Process_Data_From_Local_IO) would only prevent the camera from working properly.
It wouldn't lockup the controller or disable printfs. The camera code doesn't take very long to execute.
P.S.
Your autonomous code should also execute in a slow loop. It doesn't help to execute faster than you can deliver instructions to the pwms. If you check the IFI default code you'll see the autonomous section in user_routines_fast.c is really a slow loop by virtue of the line:
Code:
if (statusflag.NEW_SPI_DATA) /* 26.2ms loop area */
You just need to add your camera calls within that slow loop.
I'd advise you to pull all your autonomous code out of the user_routines_fast.c file anyway. The name of that file only confuses the issue and your freshmen programmers, since it's not true for the autonomous code.