You've come to the right place if you wonder how to append your Simulink model with C/C++ and/or Python code. Exactly such a capability is demonstrated here. A code for the PI controller with clamping is embedded into the Simulink model using four different approaches: S-Function written in m-code, MATLAB Function written in m-code, S-function written in C/C++ and MATLAB Function that invokes the external Python interpreter to run code written in Python. Enjoy!