Jakub Sadowski

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7 years, 4 months ago.

"Error: Undefined symbol arm_rfft_fast_f32 "

Hello,

I am trying to add FFT capability to my project, however I'm not even able to compile basic FFT examples from the vault.

I'm using this as example: https://developer.mbed.org/users/ColoradoRob/code/Nucleo32_fft/file/947ee109759e/main.cpp

The header that's included in my projects: https://developer.mbed.org/users/mbed_official/code/mbed/file/a97add6d7e64/TARGET_NUCLEO_L476RG/arm_math.h

After compiling i get this error: Error: Undefined symbol arm_rfft_fast_init_f32 (referred from main.NUCLEO_L476RG.o).

My target MCU board is Nucleo-L476RG, however compiling for a stm32f7 target gives me the same error.

Simillar functions from arm_math.h cannot be compiled either, even though compiler notices them and takes care of proper arguments, etc.

I have no idea how to resolve this problem in mbed environment, and i'd really like to avoid switching to other IDE. Any Idea what seems to cause this error?

Cheers, Jacob.

1 Answer

Andy A
7 years, 4 months ago.

Did you import this library into your project? https://developer.mbed.org/users/mbed_official/code/mbed-dsp/

In my projects that have used an fft I've not added any header files to my project directly, I've only ever imported that library which includes the arm_math.h file.

Accepted Answer

Thank you very much Andy, your suggestion seems to be working!

It makes me wonder, what are non-compiling examples doing on vault, did something change since they were posted?

Cheers.

posted by Jakub Sadowski 28 Jul 2017

That's the problem with using user code for examples, the quality is variable. I've seen it before where the required libraries are missing due to them creating the project in an odd way.

posted by Andy A 28 Jul 2017