stm32/matlab system object data conversion problem

I want to implement stm32 as USB_cdc using Simulink block and because Simulink stm32 doesn’t support usb so I have to create a block for this purpose. I used block driver method to do this. As you see below I created a system object and it is sending data correctly.

But when I want to use “oout” in Simulink, data is corrupted and meaningless.

Here is my procedure :

   function y = stepImpl(obj)   %#ok<MANU>
            y =uint64(0);
            
            if isempty(coder.target)
                % Place simulation output code here
            else
                % Call C-function implementing device output
                y = coder.ceval('data_change');
            end
   end
   

when data_cgange function called it dose:

1: send "oout" value to host with "CDC_Transmit_FS" function.(it is hardware layer function and work properly)

2: return "oout" value so i can use it in simulink.(it is not working)

"oout" value is filled in hardware layer and is declared "uint8_t oout[APP_RX_DATA_SIZE];" in code.

    long double data_change(void)
{
     CDC_Transmit_FS(oout, 5);
     memset (a,'\0',10);
     memcpy( a, oout, 10);
     fout = *a;
     //strtod(oout,endpoint);
    return fout;
}

Answer 1

[ali]

By configuring this part, it worked properly

    function varargout = 

        getOutputSizeImpl(~)
              varargout{1} = [10];

Answer 2

[Goutham Varanasi]

This seems to be an issue with the code. Debug the generated code in cube IDE using the below mentioned process.

1. In Model, set Build configuration as Debug: Open Model settings from Modeling tab. Go to Code Generation -> Build process. Select Debug in Build configuration
2. Build the project from Simulink.
3. Create a new STM32 Project in STM32CubeIDE. Select the required board on which you are going to debug the Simulink-generated code.
4. Click on Debug -> Debug Configuration
5. Right Click on STM32 Cortex-M C/C++ Application -> New Configuration
6. Browse the STM32 project created in Step 3 as Project
7. Browse the elf generated from Simulink in C/C++ Application and Click Debug

Note:

• Close all open files before starting debug session.

• Debugging starts in ert_main.c file. Add breakpoints and use Step Into to go inside functions. It will open the relevant source files.

• To add a specify source file for debugging, go to File -> Open File… Browse the file and use it for debugging.

[ali]

Thank you for your answer, the problem was due to output size configuration in m file, and after correcting this, it work properly.