To do this, you would need to download Simulink Support Package for Arduino Hardware. Refer to this documentation link for setup, modeling, deployment and other related stuff: https://www.mathworks.com/help/simulink/supportpkg-arduino.html
Ideally, MathWorks suggests using the MATLAB Function block to generate readable, efficient, and compact C/C++ code that can be deployed to the Arduino hardware. For a detailed overview of the MATLAB Function block, see: https://www.mathworks.com/help/simulink/ug/what-is-a-matlab-function-block.html. There are 50+ examples which can get you started with. Refer to this examples page: https://www.mathworks.com/help/simulink/examples.html?category=supportpkg-arduino
If you have existing C/C++ code from earlier versions that you wish to utilize, it will require some additional effort. Personally, I prefer the method described above for simplicity, but if you're comfortable with it, integrating legacy code shouldn't pose a significant challenge. You can use C Caller / C Function blocks to integrate your code into the Simulink model and use the header files as you are described in your query. Refer to the following documentation links:
- https://www.mathworks.com/help/simulink/ug/integrate-ccode-ccaller.html
- https://www.mathworks.com/help/simulink/ug/call-and-integrate-external-c-algorithms-into-simulink-using-c-function-blocks.html
Hope it helps!
