3 years, 2 months ago.

Undefined symbol using arm math libraries (FFT)


I am trying to calculcate the FFT of samples that I get from an ADC with DMA. I included de library "arm_math.h" and when I write this:



I compile and this happens:


I don't know if something in the initialitzation is missing or is a problem of the libraries. ¿Could you help me?

Thank you.

1 Answer

3 years, 2 months ago.

Hi Sergi,

You are trying to use functions from the CMSIS-DSP library (which is developed stand-alone outside of Mbed). Mbed offers the include file you would use for the DSP library (arm_math.h) but the library itself appears to be missing. However, the library source code is located in mbed-os\features\unsupported\dsp\cmsis-dsp.

We've been struggling to add the CMSIS-DSP library to the online compiler and are taking this up with our web team. So to use the library, it might be easier to take the project offline and manually add the *.lib file that you need from here: https://github.com/ARM-software/CMSIS_5/tree/develop/CMSIS/Lib

-Ralph, Team Mbed