2025-08-08 12:27 PM
Hello, I need to do FFT transforms of long signal traces, so using CMSIS DSP doesn't look possible because of the 4096 points limit. I tried to use fftw3 library (3.3.10). I built it using OpenSTLinux SDK from the Github source without problem. Here is configuration I used:
configure --host=arm-ostl-linux-gnueabi --enable-neon --enable-single --with-slow-timer
Library libfftw3f.a was built successfully and test app was also successfully linked with it. Here is relevant part of the test app code:
int fft_points = 131072;
2025-08-09 7:03 AM
Hi,
So you want to do a 128K FFT complex in float,
that's needing a lot of memory - sure, that enough RAM is free, for input and output arrays?
Malloc...is okay ?
2025-08-09 2:54 PM
No, it's actually real FFT, so it's like 64K complex. Turned out I didn't need to build fftw3 library myself. I'm new to STM32 development and didn't realize that Developer Package comes with shared libfftw3 libraries. When I used provided 3.6.10 library I didn't have any problem to build and run my app. Test app ran fine even with double type FFT transform.