printf hard fault

[luke514]

Whenever the compiler executes

printf("frequency %f: %f \n", ((float32_t)(i * SAMPLING_RATE) / FFT_BUFFER_SIZE), output_fft_mag);

it goes to HardFault.

I attach main.c and syscall.c

All the code that we need to analyze is inside the function void get_sineval_FFT2()

Here's the problem:

EDIT: The problem is only there when I try to printf floats ... whereas with normal strings or ints everything goes

[Tesla DeLorean]

Look at what's actually faulting. The MCU instructions and registers.

Do regular printf() or putchar() work, or do they fault too?

Keil, but the mechanics are the same..  https://github.com/cturvey/RandomNinjaChef/blob/main/KeilHardFault.c

[luke514]

Thank you for your reply!

With breakpoints, the compiler is faulting exatcly when printf is executed, it doesn't matter what its argument is ... I tried as well to write printf("Hello \n"); and HardFault occours.

Does that answer your comment? Because it is not very clear to me when you say "verify using instructions and registers" and what should I do with the code in the link you sent me

[Tesla DeLorean]

I mean at the MCU level not at the C function level. Something with finer granularity, and not the broad side of a barn..

Do you enable the FPU in your SystemInit() code?

Has it linked the appropriate C library. 32-bit ARM code will fault a CM4F processor.

The call to printf() or the code within the function?

Does the CubeIDE provide some sort of Hard Fault Analyzer function or window?

[luke514]

Another thing, in all the other projects I have, printf works correctly.

Here that I imported the arm_math.h libraries etc. following this tutorial ... it does not work. Maybe is there some incompatibility problem?

[luke514]

I can send you pictures of the functions you mention, but I have no idea what to change/check here

[AScha.3]

the CubeIDE has many great things (...if they are working...) :

[luke514]

Now I don't understand if the problem is in the code I wrote (main.c) or in some other file

Thanks @AScha.3 I didn't know about this function because I never needed it

[Pavel A.]

The last thing on the call stack is malloc_r (malloc) so check the pool (size, address....). Where _sbrk() is implemented? Do you have sysmem.c ?

[luke514]

_sbrk() is in sysmem.c