About C caller usage

Hello

I'm trying to use the C-caller block to import my C-code into simulink.

now i'm trying just a simple code as below:

#include <stdio.h>

int add_fnc (int a, int b)

{

int c;

c = a +b;

return c;

}

I do as the instruction in configuration parameter to set source file.

I run the c-caller block and set the variable name is add_func.

The warning is can not find add_func.

Can you support me?

[Mohammad Sami]

I believe the keyword extern is needed.

https://www.mathworks.com/help/simulink/ug/integrate-ccode-ccaller.html

[hoang tuan]

Thank you.

And it seems we have to create header file to mention the function prototype first.

We can not add direct the c source code only.

[Yao Ren]

Yes, a C function has to be "extern" declared to be visible to a Simulink model. You can use a ".h" header file to declare the C functions.

Alternatively, without writing a new ".h" file, you can declare the C function directly in model's "Configuration paramters > Simulation Target > Custom Code > Include headers" section using following statement.

extern int add_fnc (int a, int b);