Hi, you should understand that GPIO is configurable hardware. When you are launching the model on Raspberry it compiles in executable, that is trying to configure the MCU port as input and output simultaneously, that is incorrect.
The proposed method - using different pins connected by a wire is a good solution.
Also, you can evaluate all accessible pins and their functions by command line or script :
%create the system object, sure that no other Matlab functions drive your PI
mypi = raspi;
% watch pin diagram
showPins(mypi)
% clear system object
clear mypi;
