Why do I get an error using a microcontroller library with S-function builder?

Hello every one, I am currently working with a microcontroler (dsPIC33) and I am trying to programm it with SIMULINK.

I would like to use the S-function Builder block. I already read the associated documentation and found several examples.

I wish to import a library used by MPLAB for microcontroler's programming. I made a copy of it and managed to import it with the S-function Builder but when I try to use one of the functions (__delay32 for example) I have the following error :

error LNK2001: unresolved external symbol __delay32

Does anyone have tried to do something similar?

Thanks for your help. Helene

Answer 1

[Kaustubha Govind]

Where is __delay32 defined? Assuming that it is in an external library/source file, you need to add that file to the 'Library/Object/Source files' textbox in the Libraries pane of the S-function Builder Dialog Box.

Answer 2

[Helene]

Thanks for the answer .

Maybe I should explain a little bit more what I am trying to achieve. As I said I am proggramming a microcontroller. I already worked with MPLAB by typing my code and I was using the library libpic30 without any problem. I am now working with Simulink and Lubin Kerhuel "Simulink Blockset Embedded Target microchip devices" . I would like to do my delay instruction without to have to edit the generated code.

I already tried the Taped delay anec Transport delay blocks. They work almost fine BUT I have to enter an initial value for the output. I am more looking for something that just memorized the current value of the signal and pause for a specific amount of time. That is what brought me to the S-function builder bloc.

__delay32 is defined indeed in a external library file, libpic30.h.

I already imported it as you suggested. I found this library file in the XC16 compiler folder from MPLAB but I am programing with simulink on another computer which does not have this version of the compiler.

If it helps the __delay32 function is defined as follow :

extern void __delay32(unsigned long cycles);

But there are no more precisions about the function or about the cycles parameter.

The comments about this .h file does say that: "This file defines useful exports from libpic30.a".

Thanks, Helene

[Kaustubha Govind]

So it appears that __delay32 is only defined for the microcontroller, but not for a host/PC target? Since the Simulink model runs the S-function on the host machine during simulation, you may want to use an OS-equivalent for __delay32 (or make it a no-op) in the S-function Builder. Then, modify the generated TLC file to call __delay32 instead of its replacement, so that the generated embedded code calls __delay32, but not the S-function itself.