Please delete this post thank you.

[fkong.1]

..

[TDK]

Is there a question here? You mention arm_cmplx_mag_q15 not giving the expected result but you don't use it in your code. You'll need to include the definition for arm_cfft_sR_q31_len512 as well.

[fkong.1]

@TDK, Sorry I should have mentioned that even using the "arm_cmplx_mag_q31", I am still not getting the correct maxIndex in line19. I might be missing some stuff here and there and I am having doubt on the fixed point conversion or using wrong DSP Functions.

"You'll need to include the definition for arm_cfft_sR_q31_len512 as well"

Does that mean include this header file? arm_const_structs.h, if it is I did include this file.