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Code for measuring the signal with a specified length and sampling rate, and saving it on a SD card.
Diff: Envelope/envSignal.cpp
- Revision:
- 1:a514e4de034d
diff -r c05b00be2229 -r a514e4de034d Envelope/envSignal.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Envelope/envSignal.cpp Fri Jul 14 14:41:10 2017 +0000 @@ -0,0 +1,202 @@ +// +// Academic License - for use in teaching, academic research, and meeting +// course requirements at degree granting institutions only. Not for +// government, commercial, or other organizational use. +// File: envSignal.cpp +// +// MATLAB Coder version : 3.3 +// C/C++ source code generated on : 13-Jul-2017 15:47:47 +// + +// Include Files +#include "envSignal.h" +#include "envSignal_emxutil.h" +#include "ifft.h" +#include "fft.h" + +// Function Declarations +static float rt_hypotf(float u0, float u1); + +// Function Definitions + +// +// Arguments : float u0 +// float u1 +// Return Type : float +// +static float rt_hypotf(float u0, float u1) +{ + float y; + float a; + float b; + a = std::abs(u0); + b = std::abs(u1); + if (a < b) { + a /= b; + y = b * std::sqrt(a * a + 1.0F); + } else if (a > b) { + b /= a; + y = a * std::sqrt(b * b + 1.0F); + } else { + y = a * 1.41421354F; + } + + return y; +} + +// +// Bandpass filter signal +// Arguments : const emxArray_real32_T *x +// const emxArray_real32_T *fir_coef +// emxArray_real32_T *y +// Return Type : void +// +void envSignal(const emxArray_real32_T *x, const emxArray_real32_T *fir_coef, + emxArray_real32_T *y) +{ + emxArray_real32_T *b; + int nx_m_nb; + int naxpy; + emxArray_real32_T *b_y1; + int nb; + unsigned int uv0[2]; + int nx; + int k; + int jp; + int j; + emxArray_real32_T *x_filt; + emxArray_creal32_T *b_x; + int b_x_filt[1]; + emxArray_real32_T c_x_filt; + emxArray_creal32_T *c_x; + emxInit_real32_T1(&b, 1); + nx_m_nb = b->size[0]; + b->size[0] = x->size[1]; + emxEnsureCapacity((emxArray__common *)b, nx_m_nb, sizeof(float)); + naxpy = x->size[1]; + for (nx_m_nb = 0; nx_m_nb < naxpy; nx_m_nb++) { + b->data[nx_m_nb] = x->data[x->size[0] * nx_m_nb]; + } + + emxInit_real32_T1(&b_y1, 1); + nb = fir_coef->size[1]; + uv0[0] = (unsigned int)b->size[0]; + nx_m_nb = b_y1->size[0]; + b_y1->size[0] = (int)uv0[0]; + emxEnsureCapacity((emxArray__common *)b_y1, nx_m_nb, sizeof(float)); + nx = b->size[0]; + naxpy = b_y1->size[0]; + nx_m_nb = b_y1->size[0]; + b_y1->size[0] = naxpy; + emxEnsureCapacity((emxArray__common *)b_y1, nx_m_nb, sizeof(float)); + for (nx_m_nb = 0; nx_m_nb < naxpy; nx_m_nb++) { + b_y1->data[nx_m_nb] = 0.0F; + } + + if (b->size[0] >= (fir_coef->size[1] << 1)) { + for (k = 1; k <= nb; k++) { + for (j = k; j <= nx; j++) { + b_y1->data[j - 1] += fir_coef->data[k - 1] * b->data[j - k]; + } + } + } else { + if (b->size[0] > fir_coef->size[1]) { + nx_m_nb = b->size[0] - fir_coef->size[1]; + } else { + nx_m_nb = 0; + } + + jp = -2; + for (k = 1; k <= nx_m_nb; k++) { + jp++; + for (j = 1; j <= nb; j++) { + b_y1->data[jp + j] += b->data[jp + 1] * fir_coef->data[j - 1]; + } + } + + naxpy = b->size[0] - nx_m_nb; + for (k = nx_m_nb + 1; k <= nx; k++) { + jp++; + for (j = 1; j <= naxpy; j++) { + b_y1->data[jp + j] += b->data[jp + 1] * fir_coef->data[j - 1]; + } + + naxpy--; + } + } + + emxFree_real32_T(&b); + emxInit_real32_T(&x_filt, 2); + nx_m_nb = x_filt->size[0] * x_filt->size[1]; + x_filt->size[0] = 1; + x_filt->size[1] = b_y1->size[0]; + emxEnsureCapacity((emxArray__common *)x_filt, nx_m_nb, sizeof(float)); + naxpy = b_y1->size[0]; + for (nx_m_nb = 0; nx_m_nb < naxpy; nx_m_nb++) { + x_filt->data[x_filt->size[0] * nx_m_nb] = b_y1->data[nx_m_nb]; + } + + emxFree_real32_T(&b_y1); + emxInit_creal32_T(&b_x, 1); + + // Compute the complex valued analytic signal using fourier transform + // method, with all negative frequency components set to zero + // xAnalytic = hilbert(xfilt); + b_x_filt[0] = x_filt->size[1]; + c_x_filt = *x_filt; + c_x_filt.size = (int *)&b_x_filt; + c_x_filt.numDimensions = 1; + fft(&c_x_filt, b_x); + naxpy = x_filt->size[1]; + nx_m_nb = naxpy >> 1; + if ((naxpy & 1) == 0) { + jp = nx_m_nb; + } else { + jp = nx_m_nb + 1; + } + + for (k = 1; k + 1 <= jp; k++) { + b_x->data[k].re *= 2.0F; + b_x->data[k].im *= 2.0F; + } + + for (k = nx_m_nb + 1; k + 1 <= naxpy; k++) { + b_x->data[k].re = 0.0F; + b_x->data[k].im = 0.0F; + } + + emxInit_creal32_T(&c_x, 1); + nx_m_nb = c_x->size[0]; + c_x->size[0] = b_x->size[0]; + emxEnsureCapacity((emxArray__common *)c_x, nx_m_nb, sizeof(creal32_T)); + naxpy = b_x->size[0]; + for (nx_m_nb = 0; nx_m_nb < naxpy; nx_m_nb++) { + c_x->data[nx_m_nb] = b_x->data[nx_m_nb]; + } + + ifft(c_x, b_x); + + // Compute modulus of analytic signal + emxFree_creal32_T(&c_x); + for (nx_m_nb = 0; nx_m_nb < 2; nx_m_nb++) { + uv0[nx_m_nb] = (unsigned int)x_filt->size[nx_m_nb]; + } + + nx_m_nb = y->size[0] * y->size[1]; + y->size[0] = 1; + y->size[1] = (int)uv0[1]; + emxEnsureCapacity((emxArray__common *)y, nx_m_nb, sizeof(float)); + for (k = 0; k + 1 <= x_filt->size[1]; k++) { + y->data[k] = rt_hypotf(b_x->data[k].re, b_x->data[k].im); + } + + emxFree_creal32_T(&b_x); + emxFree_real32_T(&x_filt); +} + +// +// File trailer for envSignal.cpp +// +// [EOF] +// +