ST / X_NUCLEO_CCA02M1

Library to handle the X-NUCLEO-CCA02M1 MEMS Microphones Expansion Board.

Dependencies:   ST_I2S ST_FREQUENCY_DIVIDER USBDEVICE

Dependents:   HelloWorld_CCA02M1 HelloWorld_CCA02M1_mbedOS HelloWorld_CCA02M1 Karaoke_CCA01M1_CCA02M1_mbedOS

Fork of X_NUCLEO_CCA02M1 by ST Expansion SW Team

MEMS Microphones Library

Library to handle the X-NUCLEO-CCA02M1 MEMS Microphones Expansion Board. A single board allows to record a standard 2-channel stereo signal as an array of PCM samples (16 bit/sample); in principle, it could make use of six additional MEMS microphones to realize a 8-channel audio system.


Microphones configuration

Currently the configurations supported are the following:

  • Stereo@48KHz
  • Stereo@44.1KHz (CD audio quality)
  • Stereo@32KHz
  • Stereo@16KHz
  • Stereo@8KHz
  • Mono@48KHz
  • Mono@44.1KHz
  • Mono@32KHz
  • Mono@16KHz
  • Mono@8KHz

Mono configurations need a Jumper connecting PB_5 and PB_13 on the Morpho connector to properly work.


Platform compatibility

  • This board can be currently used with the Nucleo F4 Family only, please see the ST_I2S library compatibility for further information.
  • The library is compatible both with mbed OS 5.x and mbed classic 2.x (to work with mbed classic, the main application has to import the "events" library, which is not included into the "mbed" library).


I2S Peripheral Usage

By default this board makes use of the I2S peripheral available on Nucleo boards.


Acquiring through the USB

In order to acquire the recorded PCM audio channel with an audio SW on a PC, please connect the expansion board to a USB port of the PC, and the Nucleo board to a USB power supply.

Middlewares/OpenPDM2PCM/OpenPDMFilter.c@2:9f389fd8fb2e, 2017-04-21 (annotated)

Committer:
davide.aliprandi@st.com
Date:
Fri Apr 21 10:33:08 2017 +0200
Revision:
2:9f389fd8fb2e
Child:
6:9b8bc842aeb3
Aligned to ARM mbed codinmg style; OpenPDM2PCM middleware added.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
davide.aliprandi@st.com 2:9f389fd8fb2e 1 /**
davide.aliprandi@st.com 2:9f389fd8fb2e 2 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 3 * @file OpenPDMFilter.h
davide.aliprandi@st.com 2:9f389fd8fb2e 4 * @author CL
davide.aliprandi@st.com 2:9f389fd8fb2e 5 * @version V1.0.0
davide.aliprandi@st.com 2:9f389fd8fb2e 6 * @date 9-September-2015
davide.aliprandi@st.com 2:9f389fd8fb2e 7 * @brief Open PDM audio software decoding Library.
davide.aliprandi@st.com 2:9f389fd8fb2e 8 * This Library is used to decode and reconstruct the audio signal
davide.aliprandi@st.com 2:9f389fd8fb2e 9 * produced by ST MEMS microphone (MP45Dxxx, MP34Dxxx).
davide.aliprandi@st.com 2:9f389fd8fb2e 10 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 11 * @attention
davide.aliprandi@st.com 2:9f389fd8fb2e 12 *
davide.aliprandi@st.com 2:9f389fd8fb2e 13 * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>
davide.aliprandi@st.com 2:9f389fd8fb2e 14 *
davide.aliprandi@st.com 2:9f389fd8fb2e 15 * Licensed under MCD-ST Image SW License Agreement V2, (the "License");
davide.aliprandi@st.com 2:9f389fd8fb2e 16 * You may not use this file except in compliance with the License.
davide.aliprandi@st.com 2:9f389fd8fb2e 17 * You may obtain a copy of the License at:
davide.aliprandi@st.com 2:9f389fd8fb2e 18 *
davide.aliprandi@st.com 2:9f389fd8fb2e 19 * http://www.st.com/software_license_agreement_image_v2
davide.aliprandi@st.com 2:9f389fd8fb2e 20 *
davide.aliprandi@st.com 2:9f389fd8fb2e 21 * Unless required by applicable law or agreed to in writing, software
davide.aliprandi@st.com 2:9f389fd8fb2e 22 * distributed under the License is distributed on an "AS IS" BASIS,
davide.aliprandi@st.com 2:9f389fd8fb2e 23 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
davide.aliprandi@st.com 2:9f389fd8fb2e 24 * See the License for the specific language governing permissions and
davide.aliprandi@st.com 2:9f389fd8fb2e 25 * limitations under the License.
davide.aliprandi@st.com 2:9f389fd8fb2e 26 *
davide.aliprandi@st.com 2:9f389fd8fb2e 27 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 28 */
davide.aliprandi@st.com 2:9f389fd8fb2e 29
davide.aliprandi@st.com 2:9f389fd8fb2e 30
davide.aliprandi@st.com 2:9f389fd8fb2e 31 /* Includes ------------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 32
davide.aliprandi@st.com 2:9f389fd8fb2e 33 #include "OpenPDMFilter.h"
davide.aliprandi@st.com 2:9f389fd8fb2e 34
davide.aliprandi@st.com 2:9f389fd8fb2e 35
davide.aliprandi@st.com 2:9f389fd8fb2e 36 /* Definitions ---------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 37
davide.aliprandi@st.com 2:9f389fd8fb2e 38 #define maxDecFactor 128
davide.aliprandi@st.com 2:9f389fd8fb2e 39 #define maxVol 64
davide.aliprandi@st.com 2:9f389fd8fb2e 40 #define FilterGain 16;
davide.aliprandi@st.com 2:9f389fd8fb2e 41 #define RoundDiv(a, b) (((a)>0)?(((a)+(b)/2)/(b)):(((a)-(b)/2)/(b)))
davide.aliprandi@st.com 2:9f389fd8fb2e 42 #define SaturaLH(N, L, H) (((N)<(L))?(L):(((N)>(H))?(H):(N)))
davide.aliprandi@st.com 2:9f389fd8fb2e 43
davide.aliprandi@st.com 2:9f389fd8fb2e 44
davide.aliprandi@st.com 2:9f389fd8fb2e 45 /* Variables -----------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 46
davide.aliprandi@st.com 2:9f389fd8fb2e 47 uint32_t coef[5][maxDecFactor]; // Max sinc 5 with decimation 128
davide.aliprandi@st.com 2:9f389fd8fb2e 48 uint32_t DivideConst = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 49 int64_t SubConst = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 50 uint32_t sinc1[maxDecFactor];
davide.aliprandi@st.com 2:9f389fd8fb2e 51 uint32_t sinc2[maxDecFactor*2];
davide.aliprandi@st.com 2:9f389fd8fb2e 52 uint32_t sinc3[maxDecFactor*3];
davide.aliprandi@st.com 2:9f389fd8fb2e 53 uint32_t sinc4[maxDecFactor*4];
davide.aliprandi@st.com 2:9f389fd8fb2e 54 uint32_t sinc[maxDecFactor*5];
davide.aliprandi@st.com 2:9f389fd8fb2e 55 int64_t Z = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 56 uint16_t app;
davide.aliprandi@st.com 2:9f389fd8fb2e 57
davide.aliprandi@st.com 2:9f389fd8fb2e 58
davide.aliprandi@st.com 2:9f389fd8fb2e 59 /* Functions -----------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 60
davide.aliprandi@st.com 2:9f389fd8fb2e 61 int64_t filterTable(uint8_t *data, uint8_t table, TPDMFilter_InitStruct *Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 62
davide.aliprandi@st.com 2:9f389fd8fb2e 63 void convolve(uint32_t Signal[/* SignalLen */], unsigned short SignalLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 64 uint32_t Kernel[/* KernelLen */], unsigned short KernelLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 65 uint32_t Result[/* SignalLen + KernelLen - 1 */]);
davide.aliprandi@st.com 2:9f389fd8fb2e 66
davide.aliprandi@st.com 2:9f389fd8fb2e 67 int64_t filterTable(uint8_t *data, uint8_t table, TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 68 {
davide.aliprandi@st.com 2:9f389fd8fb2e 69 uint16_t contatore = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 70 int64_t F = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 71 uint8_t c;
davide.aliprandi@st.com 2:9f389fd8fb2e 72 uint8_t i;
davide.aliprandi@st.com 2:9f389fd8fb2e 73 uint16_t internalBit = Param->bit[table];
davide.aliprandi@st.com 2:9f389fd8fb2e 74 uint16_t internalBit_copy = internalBit;
davide.aliprandi@st.com 2:9f389fd8fb2e 75 uint16_t In_Mic = Param->In_MicChannels;
davide.aliprandi@st.com 2:9f389fd8fb2e 76
davide.aliprandi@st.com 2:9f389fd8fb2e 77 c = data[0];
davide.aliprandi@st.com 2:9f389fd8fb2e 78 for(i=0; i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 79 {
davide.aliprandi@st.com 2:9f389fd8fb2e 80 if (c & (1<<((7-internalBit))))
davide.aliprandi@st.com 2:9f389fd8fb2e 81 F += coef[table][i];
davide.aliprandi@st.com 2:9f389fd8fb2e 82 internalBit++;
davide.aliprandi@st.com 2:9f389fd8fb2e 83 if(internalBit==8)
davide.aliprandi@st.com 2:9f389fd8fb2e 84 {
davide.aliprandi@st.com 2:9f389fd8fb2e 85 contatore+=In_Mic;
davide.aliprandi@st.com 2:9f389fd8fb2e 86 internalBit = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 87 c = data[contatore];
davide.aliprandi@st.com 2:9f389fd8fb2e 88 }
davide.aliprandi@st.com 2:9f389fd8fb2e 89 }
davide.aliprandi@st.com 2:9f389fd8fb2e 90 Param->bit[table] = internalBit;
davide.aliprandi@st.com 2:9f389fd8fb2e 91 Param->byte = contatore;
davide.aliprandi@st.com 2:9f389fd8fb2e 92
davide.aliprandi@st.com 2:9f389fd8fb2e 93 return F;
davide.aliprandi@st.com 2:9f389fd8fb2e 94 }
davide.aliprandi@st.com 2:9f389fd8fb2e 95
davide.aliprandi@st.com 2:9f389fd8fb2e 96 void Open_PDM_Filter_Init(TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 97 {
davide.aliprandi@st.com 2:9f389fd8fb2e 98 uint16_t i,j;
davide.aliprandi@st.com 2:9f389fd8fb2e 99 int64_t sum = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 100 Param->Coef[0] = Param->Coef[1] = Param->Coef[2] = Param->Coef[3] = Param->Coef[4] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 101 for(i=0;i<5;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 102 {
davide.aliprandi@st.com 2:9f389fd8fb2e 103 Param->bit[i]=0;
davide.aliprandi@st.com 2:9f389fd8fb2e 104 }
davide.aliprandi@st.com 2:9f389fd8fb2e 105
davide.aliprandi@st.com 2:9f389fd8fb2e 106 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 107 {
davide.aliprandi@st.com 2:9f389fd8fb2e 108 sinc1[i]=1;
davide.aliprandi@st.com 2:9f389fd8fb2e 109 }
davide.aliprandi@st.com 2:9f389fd8fb2e 110 Param->OldOut = Param->OldIn = Param->OldZ = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 111 if(Param->LP_HZ!=0)
davide.aliprandi@st.com 2:9f389fd8fb2e 112 {
davide.aliprandi@st.com 2:9f389fd8fb2e 113 Param->LP_ALFA = (uint16_t)(Param->LP_HZ*256 / (Param->LP_HZ + Param->Fs/(2*3.14)));
davide.aliprandi@st.com 2:9f389fd8fb2e 114 }else
davide.aliprandi@st.com 2:9f389fd8fb2e 115 {
davide.aliprandi@st.com 2:9f389fd8fb2e 116 Param->LP_ALFA = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 117 }
davide.aliprandi@st.com 2:9f389fd8fb2e 118
davide.aliprandi@st.com 2:9f389fd8fb2e 119 if(Param->HP_HZ!=0)
davide.aliprandi@st.com 2:9f389fd8fb2e 120 {
davide.aliprandi@st.com 2:9f389fd8fb2e 121 Param->HP_ALFA = (uint16_t)(Param->Fs*256 / (2*3.14*Param->HP_HZ + Param->Fs));
davide.aliprandi@st.com 2:9f389fd8fb2e 122 }else
davide.aliprandi@st.com 2:9f389fd8fb2e 123 {
davide.aliprandi@st.com 2:9f389fd8fb2e 124 Param->HP_ALFA = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 125 }
davide.aliprandi@st.com 2:9f389fd8fb2e 126
davide.aliprandi@st.com 2:9f389fd8fb2e 127 switch(Param->SincN)
davide.aliprandi@st.com 2:9f389fd8fb2e 128 {
davide.aliprandi@st.com 2:9f389fd8fb2e 129 case 1:
davide.aliprandi@st.com 2:9f389fd8fb2e 130 Param->FilterLen = Param->Decimation;
davide.aliprandi@st.com 2:9f389fd8fb2e 131
davide.aliprandi@st.com 2:9f389fd8fb2e 132 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 133 {
davide.aliprandi@st.com 2:9f389fd8fb2e 134 coef[0][i]=1;
davide.aliprandi@st.com 2:9f389fd8fb2e 135 sum+= 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 136 }
davide.aliprandi@st.com 2:9f389fd8fb2e 137 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 138 case 2:
davide.aliprandi@st.com 2:9f389fd8fb2e 139 Param->FilterLen = Param->Decimation * 2;
davide.aliprandi@st.com 2:9f389fd8fb2e 140
davide.aliprandi@st.com 2:9f389fd8fb2e 141 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 142
davide.aliprandi@st.com 2:9f389fd8fb2e 143 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,&sinc[1]);
davide.aliprandi@st.com 2:9f389fd8fb2e 144
davide.aliprandi@st.com 2:9f389fd8fb2e 145 for(j=0;j<2;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 146 {
davide.aliprandi@st.com 2:9f389fd8fb2e 147 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 148 {
davide.aliprandi@st.com 2:9f389fd8fb2e 149 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 150 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 151 }
davide.aliprandi@st.com 2:9f389fd8fb2e 152 }
davide.aliprandi@st.com 2:9f389fd8fb2e 153
davide.aliprandi@st.com 2:9f389fd8fb2e 154 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 155 case 3:
davide.aliprandi@st.com 2:9f389fd8fb2e 156 Param->FilterLen = Param->Decimation * 3;
davide.aliprandi@st.com 2:9f389fd8fb2e 157 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 158 sinc[Param->Decimation*3-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 159 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 160 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,&sinc[1]);
davide.aliprandi@st.com 2:9f389fd8fb2e 161 for(j=0;j<3;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 162 {
davide.aliprandi@st.com 2:9f389fd8fb2e 163 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 164 {
davide.aliprandi@st.com 2:9f389fd8fb2e 165 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 166 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 167 }
davide.aliprandi@st.com 2:9f389fd8fb2e 168 }
davide.aliprandi@st.com 2:9f389fd8fb2e 169 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 170 case 4:
davide.aliprandi@st.com 2:9f389fd8fb2e 171 Param->FilterLen = Param->Decimation * 4;
davide.aliprandi@st.com 2:9f389fd8fb2e 172 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 173 sinc[1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 174 sinc[Param->Decimation*4-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 175 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 176 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,sinc3);
davide.aliprandi@st.com 2:9f389fd8fb2e 177 convolve(sinc3, Param->Decimation*3-2,sinc1,Param->Decimation,&sinc[2]);
davide.aliprandi@st.com 2:9f389fd8fb2e 178 for(j=0;j<4;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 179 {
davide.aliprandi@st.com 2:9f389fd8fb2e 180 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 181 {
davide.aliprandi@st.com 2:9f389fd8fb2e 182 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 183 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 184 }
davide.aliprandi@st.com 2:9f389fd8fb2e 185 }
davide.aliprandi@st.com 2:9f389fd8fb2e 186
davide.aliprandi@st.com 2:9f389fd8fb2e 187 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 188 case 5:
davide.aliprandi@st.com 2:9f389fd8fb2e 189 Param->FilterLen = Param->Decimation*5; // Dec * 5 - 2
davide.aliprandi@st.com 2:9f389fd8fb2e 190 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 191 sinc[1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 192 sinc[Param->Decimation*5-2] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 193 sinc[Param->Decimation*5-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 194
davide.aliprandi@st.com 2:9f389fd8fb2e 195 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 196 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,sinc3);
davide.aliprandi@st.com 2:9f389fd8fb2e 197 convolve(sinc3, Param->Decimation*3-2,sinc1,Param->Decimation,sinc4);
davide.aliprandi@st.com 2:9f389fd8fb2e 198 convolve(sinc4, Param->Decimation*4-3,sinc1,Param->Decimation,&sinc[2]);
davide.aliprandi@st.com 2:9f389fd8fb2e 199
davide.aliprandi@st.com 2:9f389fd8fb2e 200 for(j=0;j<5;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 201 {
davide.aliprandi@st.com 2:9f389fd8fb2e 202 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 203 {
davide.aliprandi@st.com 2:9f389fd8fb2e 204 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 205 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 206 }
davide.aliprandi@st.com 2:9f389fd8fb2e 207 }
davide.aliprandi@st.com 2:9f389fd8fb2e 208 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 209 }
davide.aliprandi@st.com 2:9f389fd8fb2e 210 SubConst = sum / 2;
davide.aliprandi@st.com 2:9f389fd8fb2e 211 DivideConst = SubConst*maxVol/32768/FilterGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 212 if(DivideConst == 0 ) DivideConst = 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 213 }
davide.aliprandi@st.com 2:9f389fd8fb2e 214
davide.aliprandi@st.com 2:9f389fd8fb2e 215 void convolve(uint32_t Signal[/* SignalLen */], unsigned short SignalLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 216 uint32_t Kernel[/* KernelLen */], unsigned short KernelLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 217 uint32_t Result[/* SignalLen + KernelLen - 1 */])
davide.aliprandi@st.com 2:9f389fd8fb2e 218 {
davide.aliprandi@st.com 2:9f389fd8fb2e 219 uint16_t n;
davide.aliprandi@st.com 2:9f389fd8fb2e 220 for (n = 0; n < SignalLen + KernelLen - 1; n++)
davide.aliprandi@st.com 2:9f389fd8fb2e 221 {
davide.aliprandi@st.com 2:9f389fd8fb2e 222 unsigned short kmin, kmax, k;
davide.aliprandi@st.com 2:9f389fd8fb2e 223
davide.aliprandi@st.com 2:9f389fd8fb2e 224 Result[n] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 225
davide.aliprandi@st.com 2:9f389fd8fb2e 226 kmin = (n >= KernelLen - 1) ? n - (KernelLen - 1) : 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 227 kmax = (n < SignalLen - 1) ? n : SignalLen - 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 228
davide.aliprandi@st.com 2:9f389fd8fb2e 229 for (k = kmin; k <= kmax; k++)
davide.aliprandi@st.com 2:9f389fd8fb2e 230 {
davide.aliprandi@st.com 2:9f389fd8fb2e 231 Result[n] += Signal[k] * Kernel[n - k];
davide.aliprandi@st.com 2:9f389fd8fb2e 232 }
davide.aliprandi@st.com 2:9f389fd8fb2e 233 }
davide.aliprandi@st.com 2:9f389fd8fb2e 234 }
davide.aliprandi@st.com 2:9f389fd8fb2e 235
davide.aliprandi@st.com 2:9f389fd8fb2e 236 void Open_PDM_Filter(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 237 {
davide.aliprandi@st.com 2:9f389fd8fb2e 238 uint32_t i;
davide.aliprandi@st.com 2:9f389fd8fb2e 239 int64_t OldOut, OldIn, OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 240 OldOut=Param->OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 241 OldIn=Param->OldIn;
davide.aliprandi@st.com 2:9f389fd8fb2e 242 OldZ=Param->OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 243
davide.aliprandi@st.com 2:9f389fd8fb2e 244 for (i = 0; i < Param->Fs/1000; i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 245 {
davide.aliprandi@st.com 2:9f389fd8fb2e 246 switch(Param->SincN)
davide.aliprandi@st.com 2:9f389fd8fb2e 247 {
davide.aliprandi@st.com 2:9f389fd8fb2e 248 case 1:
davide.aliprandi@st.com 2:9f389fd8fb2e 249 Z = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 250 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 251 case 2:
davide.aliprandi@st.com 2:9f389fd8fb2e 252 Z = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 253 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 254 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 255 case 3:
davide.aliprandi@st.com 2:9f389fd8fb2e 256 Z = Param->Coef[1] + filterTable(data,2, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 257 Param->Coef[1] = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 258 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 259 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 260 case 4:
davide.aliprandi@st.com 2:9f389fd8fb2e 261 Z = Param->Coef[2] + filterTable(data,3, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 262 Param->Coef[2] = Param->Coef[1] + filterTable(data,2, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 263 Param->Coef[1] = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 264 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 265 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 266 case 5:
davide.aliprandi@st.com 2:9f389fd8fb2e 267 Z = Param->Coef[3] + filterTable(data,4, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 268 Param->Coef[3] = Param->Coef[2] + filterTable(data,3, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 269 Param->Coef[2] = Param->Coef[1] + filterTable(data,2, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 270 Param->Coef[1] = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 271 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 272 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 273 }
davide.aliprandi@st.com 2:9f389fd8fb2e 274
davide.aliprandi@st.com 2:9f389fd8fb2e 275 Z-=SubConst;
davide.aliprandi@st.com 2:9f389fd8fb2e 276
davide.aliprandi@st.com 2:9f389fd8fb2e 277 if(Param->HP_ALFA!= 0)
davide.aliprandi@st.com 2:9f389fd8fb2e 278 {
davide.aliprandi@st.com 2:9f389fd8fb2e 279 OldOut = (Param->HP_ALFA * (OldOut + Z - OldIn))/256;
davide.aliprandi@st.com 2:9f389fd8fb2e 280 OldIn=Z;
davide.aliprandi@st.com 2:9f389fd8fb2e 281 Z=OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 282 }
davide.aliprandi@st.com 2:9f389fd8fb2e 283
davide.aliprandi@st.com 2:9f389fd8fb2e 284 if(Param->LP_ALFA != 0)
davide.aliprandi@st.com 2:9f389fd8fb2e 285 {
davide.aliprandi@st.com 2:9f389fd8fb2e 286 OldZ = ((256-Param->LP_ALFA)*OldZ+Param->LP_ALFA*Z)/256;
davide.aliprandi@st.com 2:9f389fd8fb2e 287 Z = OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 288 }
davide.aliprandi@st.com 2:9f389fd8fb2e 289
davide.aliprandi@st.com 2:9f389fd8fb2e 290 // if(Param->SincN>=3){
davide.aliprandi@st.com 2:9f389fd8fb2e 291 // Z = RoundDiv(Z, DivideConst);
davide.aliprandi@st.com 2:9f389fd8fb2e 292 // Z *= MicGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 293 // }else{
davide.aliprandi@st.com 2:9f389fd8fb2e 294 Z *= MicGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 295 Z = RoundDiv(Z, DivideConst);
davide.aliprandi@st.com 2:9f389fd8fb2e 296 // }
davide.aliprandi@st.com 2:9f389fd8fb2e 297 Z = SaturaLH(Z, -32700, 32700); // saturation
davide.aliprandi@st.com 2:9f389fd8fb2e 298 dataOut[i*Param->Out_MicChannels] = Z ;
davide.aliprandi@st.com 2:9f389fd8fb2e 299 // data+=(Param->Decimation-app)/8 * Param->In_MicChannels;
davide.aliprandi@st.com 2:9f389fd8fb2e 300 data+=Param->byte;
davide.aliprandi@st.com 2:9f389fd8fb2e 301 // data+=Param->Decimation/8*Param->In_MicChannels;
davide.aliprandi@st.com 2:9f389fd8fb2e 302 }
davide.aliprandi@st.com 2:9f389fd8fb2e 303 Param->OldOut=OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 304 Param->OldIn=OldIn;
davide.aliprandi@st.com 2:9f389fd8fb2e 305 Param->OldZ=OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 306 }