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MSPM0G1107: CMSIS FFT-512 Q15

Baskar R
Prodigy 90 points
Part Number: MSPM0G1107
Other Parts Discussed in Thread: ADS131M04

Tool/software:

We are designed with MSPM0 based processor for one of digital signal processing application.
We are collected 512 sampled of 16-bit ADC data through ADS131M04 sampling with 8192 Hz and processing the data using CMSIS FFT Q15 library to find the Maximum Frequency Index.

#define NUM_SAMPLES 512
#define IFFTFLAG 0
#define BITREVERSE 1

Input Signal: gDstBuffer[NUM_SAMPLES]

Output FFT: gFFTOutput[NUM_SAMPLES]

   arm_cfft_q15(&arm_cfft_sR_q15_len512, (q15_t *) gDstBuffer, IFFTFLAG, BITREVERSE);
   arm_cmplx_mag_q15((q15_t *) gDstBuffer, (q15_t *) gFFTOutput, NUM_SAMPLES);
   arm_max_q15((q15_t *) gFFTOutput, NUM_SAMPLES, (q15_t *) &gFFTmaxValue,(uint32_t *) &gFFTmaxFreqIndex);
But the Maximum Frequency Index always getting '0' at gFFTmaxFreqIndex.

Is it possible to provide proper steps to follow the FFT process for 512 sampled 16-bit ADC data to find the Maximum Frequency Index.