Undefined reference to a function (my function)

1

I have a fuction declaration:

int Medienwechsel(double xi, double yi, double zi);

then i call this function:

x = 20.0;
y = 20.0;
z = 20.0;
pos = Medienwechsel(x,y,z);

and then it shows the following error:

C:\Users\marti\AppData\Local\Temp\ccMVqLbB.ltrans0.ltrans.o: In function main': <artificial>:(.text.startup+0x3a4): undefined reference to Medienwechsel(double, double, double)’
collect2.exe: error: ld returned 1 exit status
*** [.pio\build\megaatmega2560\firmware.elf] Error 1

The strange thing is, that it word if i use int insted of double…

Hope you can help me!
Thank you!

2

In which file is the Medienwechsel function implemented (filename + location)?

If you try calling .c code from .cpp code, you must use extern "C" { #include "your header.h" } in the .cpp code.

3

the function is declared and implemented in the main.cpp. And the main is in the .src

4

Please show the full source code.

5

code was here, but the mistake was so stupid…

6

So you declared the function as taking 3 doubles but implemented the function as taking 3 integers. As far as C++ is concerned, those are different functions (remember. C++ allows overloads of functions with different types).

Since xi, yi and zi are used in for loops as whole numbers, and you can’t have a fraction of a loop iteration, it makes most sense to adapt the declaration to use int too. I.e., correct

to

int Medienwechsel(int xi, int yi, int zi);
7

Thanks!
Omg. That day was too long. What a stupid mistake and i was searching hours. :wink:

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