use cmsis_dsp_sys::{arm_sin_f32};
let sin = unsafe { arm_sin_f32(core::f32::consts::PI) };
assert_eq!(sin, 0f32);

use cmsis_dsp_sys::{arm_cfft_sR_f32_len16, arm_cfft_f32, arm_cfft_instance_f32, arm_cmplx_mag_f32};
use micromath::F32Ext;
//C needs access to a sqrt fn, lets use micromath
#[no_mangle]
pub extern "C" fn sqrtf(x: f32) -> f32 {
    x.sqrt()
}
...
    //your data as stored as real and imaginary pairs here
    let mut dtfsecoef = [0f32; 32];
    let mut mag = [0f32; 16];
    //Coefficient calculation with CFFT function
    unsafe {
        //CFFT calculation
        arm_cfft_f32(&arm_cfft_sR_f32_len16, dtfsecoef.as_mut_ptr(), 0, 1);
        // Magnitude calculation
        arm_cmplx_mag_f32(s.as_ptr(), mag.as_mut_ptr(), N::to_usize() as uint32_t);
    }
...