TouchGFX Simulator not recognize variable exported from another xxx.c file

[gevmar]

please help someone if you can. The program in CubeIDE compiles and Run without errors , but TouchGFX Simulator not recognize variable exported from another xxx.c file (   usbd_cdc_if.c ; uint8_t my_char_Rx_buf ; ) . In Screen1View.cpp file  (  extern uint8_t my_char_Rx_buf ; ) . 

In TouchGFX 

.......Screen1View.cpp:72: undefined reference to `my_char_Rx_buf ...

collect2.exe: error: ld returned 1 exit status
generated/simulator/gcc/Makefile:160: recipe for target 'build/bin/simulator.exe' failed

[GaetanGodart]

Hello @gevmar 

1.

It looks like a make file error according to the error message. This could be because you are trying to use C code in C++ program.

Where do you include usbd_cdc_if.c?

You probably have to include the header as external c.

Example:

extern "C"
{
#include "My_C_Header.h"
}

For your case, it would probably look something like that :

extern "C"
{
#include " usbd_cdc_if.h"
}

2.

If this step is done and the error persists, try making use of the Model-View-Presenter Design Pattern used by TouchGFX.
Here is the documentation about the MVP Design Pattern :  MVP design pattern 

Here is the tutorial using the MVP Design Pattern : MVP tutorial 

3.

Sharing your project could help us understand the issue.

Hope this helps.

Don’t hesitate to give us a feedback or give more precisions.