CMSIS DSP

void calc_cos(float32_t* src, float32_t per, uint32_t pt){
    float32_t pi32 = PI / per;
    for(uint32_t volatile i=0; i<pt; i++){
        src[i] = 10000.0 * arm_cos_f32( i / pi32 );
    };
};


void calc_dfft(float32_t* src, uint32_t pt){
    arm_status status = arm_cfft_init_f32(&a, pt);
    arm_cfft_f32(&a, srcv, 0, 1);
    arm_cmplx_mag_f32(srcv, dstv, 128);
};

calc_cos(srcv, 1.0, 256);
calc_dfft(srcv, 256);