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@6:9b8bc842aeb3, 2017-04-21 (annotated)

Committer:
davide.aliprandi@st.com
Date:
Fri Apr 21 19:39:27 2017 +0200
Revision:
6:9b8bc842aeb3
Parent:
2:9f389fd8fb2e
Child:
11:b2f7f79026e4
Closed PDM2PCM library removed.

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 6:9b8bc842aeb3 67 inline int64_t filterTable(uint8_t *data, uint8_t table, TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 68 {
davide.aliprandi@st.com 6:9b8bc842aeb3 69 uint16_t counter = 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 6:9b8bc842aeb3 73 uint16_t internal_bit = Param->bit[table];
davide.aliprandi@st.com 2:9f389fd8fb2e 74 uint16_t In_Mic = Param->In_MicChannels;
davide.aliprandi@st.com 2:9f389fd8fb2e 75
davide.aliprandi@st.com 2:9f389fd8fb2e 76 c = data[0];
davide.aliprandi@st.com 6:9b8bc842aeb3 77 for (i=0; i<Param->Decimation; i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 78 {
davide.aliprandi@st.com 6:9b8bc842aeb3 79 if (c & (1<<((7-internal_bit))))
davide.aliprandi@st.com 2:9f389fd8fb2e 80 F += coef[table][i];
davide.aliprandi@st.com 6:9b8bc842aeb3 81 internal_bit++;
davide.aliprandi@st.com 6:9b8bc842aeb3 82 if (internal_bit==8)
davide.aliprandi@st.com 2:9f389fd8fb2e 83 {
davide.aliprandi@st.com 6:9b8bc842aeb3 84 counter += In_Mic;
davide.aliprandi@st.com 6:9b8bc842aeb3 85 internal_bit = 0;
davide.aliprandi@st.com 6:9b8bc842aeb3 86 c = data[counter];
davide.aliprandi@st.com 2:9f389fd8fb2e 87 }
davide.aliprandi@st.com 2:9f389fd8fb2e 88 }
davide.aliprandi@st.com 6:9b8bc842aeb3 89 Param->bit[table] = internal_bit;
davide.aliprandi@st.com 6:9b8bc842aeb3 90 Param->byte = counter;
davide.aliprandi@st.com 2:9f389fd8fb2e 91
davide.aliprandi@st.com 2:9f389fd8fb2e 92 return F;
davide.aliprandi@st.com 2:9f389fd8fb2e 93 }
davide.aliprandi@st.com 2:9f389fd8fb2e 94
davide.aliprandi@st.com 2:9f389fd8fb2e 95 void Open_PDM_Filter_Init(TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 96 {
davide.aliprandi@st.com 2:9f389fd8fb2e 97 uint16_t i,j;
davide.aliprandi@st.com 2:9f389fd8fb2e 98 int64_t sum = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 99 Param->Coef[0] = Param->Coef[1] = Param->Coef[2] = Param->Coef[3] = Param->Coef[4] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 100 for(i=0;i<5;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 101 {
davide.aliprandi@st.com 2:9f389fd8fb2e 102 Param->bit[i]=0;
davide.aliprandi@st.com 2:9f389fd8fb2e 103 }
davide.aliprandi@st.com 2:9f389fd8fb2e 104
davide.aliprandi@st.com 2:9f389fd8fb2e 105 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 106 {
davide.aliprandi@st.com 2:9f389fd8fb2e 107 sinc1[i]=1;
davide.aliprandi@st.com 2:9f389fd8fb2e 108 }
davide.aliprandi@st.com 2:9f389fd8fb2e 109 Param->OldOut = Param->OldIn = Param->OldZ = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 110 if(Param->LP_HZ!=0)
davide.aliprandi@st.com 2:9f389fd8fb2e 111 {
davide.aliprandi@st.com 2:9f389fd8fb2e 112 Param->LP_ALFA = (uint16_t)(Param->LP_HZ*256 / (Param->LP_HZ + Param->Fs/(2*3.14)));
davide.aliprandi@st.com 2:9f389fd8fb2e 113 }else
davide.aliprandi@st.com 2:9f389fd8fb2e 114 {
davide.aliprandi@st.com 2:9f389fd8fb2e 115 Param->LP_ALFA = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 116 }
davide.aliprandi@st.com 2:9f389fd8fb2e 117
davide.aliprandi@st.com 2:9f389fd8fb2e 118 if(Param->HP_HZ!=0)
davide.aliprandi@st.com 2:9f389fd8fb2e 119 {
davide.aliprandi@st.com 2:9f389fd8fb2e 120 Param->HP_ALFA = (uint16_t)(Param->Fs*256 / (2*3.14*Param->HP_HZ + Param->Fs));
davide.aliprandi@st.com 2:9f389fd8fb2e 121 }else
davide.aliprandi@st.com 2:9f389fd8fb2e 122 {
davide.aliprandi@st.com 2:9f389fd8fb2e 123 Param->HP_ALFA = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 124 }
davide.aliprandi@st.com 2:9f389fd8fb2e 125
davide.aliprandi@st.com 2:9f389fd8fb2e 126 switch(Param->SincN)
davide.aliprandi@st.com 2:9f389fd8fb2e 127 {
davide.aliprandi@st.com 2:9f389fd8fb2e 128 case 1:
davide.aliprandi@st.com 2:9f389fd8fb2e 129 Param->FilterLen = Param->Decimation;
davide.aliprandi@st.com 2:9f389fd8fb2e 130
davide.aliprandi@st.com 2:9f389fd8fb2e 131 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 132 {
davide.aliprandi@st.com 2:9f389fd8fb2e 133 coef[0][i]=1;
davide.aliprandi@st.com 2:9f389fd8fb2e 134 sum+= 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 135 }
davide.aliprandi@st.com 2:9f389fd8fb2e 136 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 137 case 2:
davide.aliprandi@st.com 2:9f389fd8fb2e 138 Param->FilterLen = Param->Decimation * 2;
davide.aliprandi@st.com 2:9f389fd8fb2e 139
davide.aliprandi@st.com 2:9f389fd8fb2e 140 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 141
davide.aliprandi@st.com 2:9f389fd8fb2e 142 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,&sinc[1]);
davide.aliprandi@st.com 2:9f389fd8fb2e 143
davide.aliprandi@st.com 2:9f389fd8fb2e 144 for(j=0;j<2;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 145 {
davide.aliprandi@st.com 2:9f389fd8fb2e 146 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 147 {
davide.aliprandi@st.com 2:9f389fd8fb2e 148 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 149 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 150 }
davide.aliprandi@st.com 2:9f389fd8fb2e 151 }
davide.aliprandi@st.com 2:9f389fd8fb2e 152
davide.aliprandi@st.com 2:9f389fd8fb2e 153 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 154 case 3:
davide.aliprandi@st.com 2:9f389fd8fb2e 155 Param->FilterLen = Param->Decimation * 3;
davide.aliprandi@st.com 2:9f389fd8fb2e 156 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 157 sinc[Param->Decimation*3-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 158 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 159 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,&sinc[1]);
davide.aliprandi@st.com 2:9f389fd8fb2e 160 for(j=0;j<3;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 161 {
davide.aliprandi@st.com 2:9f389fd8fb2e 162 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 163 {
davide.aliprandi@st.com 2:9f389fd8fb2e 164 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 165 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 166 }
davide.aliprandi@st.com 2:9f389fd8fb2e 167 }
davide.aliprandi@st.com 2:9f389fd8fb2e 168 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 169 case 4:
davide.aliprandi@st.com 2:9f389fd8fb2e 170 Param->FilterLen = Param->Decimation * 4;
davide.aliprandi@st.com 2:9f389fd8fb2e 171 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 172 sinc[1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 173 sinc[Param->Decimation*4-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 174 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 175 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,sinc3);
davide.aliprandi@st.com 2:9f389fd8fb2e 176 convolve(sinc3, Param->Decimation*3-2,sinc1,Param->Decimation,&sinc[2]);
davide.aliprandi@st.com 2:9f389fd8fb2e 177 for(j=0;j<4;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 178 {
davide.aliprandi@st.com 2:9f389fd8fb2e 179 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 180 {
davide.aliprandi@st.com 2:9f389fd8fb2e 181 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 182 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 183 }
davide.aliprandi@st.com 2:9f389fd8fb2e 184 }
davide.aliprandi@st.com 2:9f389fd8fb2e 185
davide.aliprandi@st.com 2:9f389fd8fb2e 186 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 187 case 5:
davide.aliprandi@st.com 2:9f389fd8fb2e 188 Param->FilterLen = Param->Decimation*5; // Dec * 5 - 2
davide.aliprandi@st.com 2:9f389fd8fb2e 189 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 190 sinc[1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 191 sinc[Param->Decimation*5-2] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 192 sinc[Param->Decimation*5-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 193
davide.aliprandi@st.com 2:9f389fd8fb2e 194 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 195 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,sinc3);
davide.aliprandi@st.com 2:9f389fd8fb2e 196 convolve(sinc3, Param->Decimation*3-2,sinc1,Param->Decimation,sinc4);
davide.aliprandi@st.com 2:9f389fd8fb2e 197 convolve(sinc4, Param->Decimation*4-3,sinc1,Param->Decimation,&sinc[2]);
davide.aliprandi@st.com 2:9f389fd8fb2e 198
davide.aliprandi@st.com 2:9f389fd8fb2e 199 for(j=0;j<5;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 200 {
davide.aliprandi@st.com 2:9f389fd8fb2e 201 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 202 {
davide.aliprandi@st.com 2:9f389fd8fb2e 203 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 204 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 205 }
davide.aliprandi@st.com 2:9f389fd8fb2e 206 }
davide.aliprandi@st.com 2:9f389fd8fb2e 207 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 208 }
davide.aliprandi@st.com 2:9f389fd8fb2e 209 SubConst = sum / 2;
davide.aliprandi@st.com 2:9f389fd8fb2e 210 DivideConst = SubConst*maxVol/32768/FilterGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 211 if(DivideConst == 0 ) DivideConst = 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 212 }
davide.aliprandi@st.com 2:9f389fd8fb2e 213
davide.aliprandi@st.com 2:9f389fd8fb2e 214 void convolve(uint32_t Signal[/* SignalLen */], unsigned short SignalLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 215 uint32_t Kernel[/* KernelLen */], unsigned short KernelLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 216 uint32_t Result[/* SignalLen + KernelLen - 1 */])
davide.aliprandi@st.com 2:9f389fd8fb2e 217 {
davide.aliprandi@st.com 2:9f389fd8fb2e 218 uint16_t n;
davide.aliprandi@st.com 2:9f389fd8fb2e 219 for (n = 0; n < SignalLen + KernelLen - 1; n++)
davide.aliprandi@st.com 2:9f389fd8fb2e 220 {
davide.aliprandi@st.com 2:9f389fd8fb2e 221 unsigned short kmin, kmax, k;
davide.aliprandi@st.com 2:9f389fd8fb2e 222
davide.aliprandi@st.com 2:9f389fd8fb2e 223 Result[n] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 224
davide.aliprandi@st.com 2:9f389fd8fb2e 225 kmin = (n >= KernelLen - 1) ? n - (KernelLen - 1) : 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 226 kmax = (n < SignalLen - 1) ? n : SignalLen - 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 227
davide.aliprandi@st.com 2:9f389fd8fb2e 228 for (k = kmin; k <= kmax; k++)
davide.aliprandi@st.com 2:9f389fd8fb2e 229 {
davide.aliprandi@st.com 2:9f389fd8fb2e 230 Result[n] += Signal[k] * Kernel[n - k];
davide.aliprandi@st.com 2:9f389fd8fb2e 231 }
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 void Open_PDM_Filter(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 236 {
davide.aliprandi@st.com 2:9f389fd8fb2e 237 uint32_t i;
davide.aliprandi@st.com 2:9f389fd8fb2e 238 int64_t OldOut, OldIn, OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 239 OldOut=Param->OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 240 OldIn=Param->OldIn;
davide.aliprandi@st.com 2:9f389fd8fb2e 241 OldZ=Param->OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 242
davide.aliprandi@st.com 2:9f389fd8fb2e 243 for (i = 0; i < Param->Fs/1000; i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 244 {
davide.aliprandi@st.com 2:9f389fd8fb2e 245 switch(Param->SincN)
davide.aliprandi@st.com 2:9f389fd8fb2e 246 {
davide.aliprandi@st.com 2:9f389fd8fb2e 247 case 1:
davide.aliprandi@st.com 2:9f389fd8fb2e 248 Z = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 249 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 250 case 2:
davide.aliprandi@st.com 2:9f389fd8fb2e 251 Z = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 252 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 253 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 254 case 3:
davide.aliprandi@st.com 2:9f389fd8fb2e 255 Z = Param->Coef[1] + filterTable(data,2, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 256 Param->Coef[1] = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 257 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 258 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 259 case 4:
davide.aliprandi@st.com 2:9f389fd8fb2e 260 Z = Param->Coef[2] + filterTable(data,3, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 261 Param->Coef[2] = Param->Coef[1] + filterTable(data,2, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 262 Param->Coef[1] = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 263 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 264 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 265 case 5:
davide.aliprandi@st.com 2:9f389fd8fb2e 266 Z = Param->Coef[3] + filterTable(data,4, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 267 Param->Coef[3] = Param->Coef[2] + filterTable(data,3, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 268 Param->Coef[2] = Param->Coef[1] + filterTable(data,2, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 269 Param->Coef[1] = Param->Coef[0] + filterTable(data,1, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 270 Param->Coef[0] = filterTable(data,0, Param);
davide.aliprandi@st.com 2:9f389fd8fb2e 271 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 272 }
davide.aliprandi@st.com 2:9f389fd8fb2e 273
davide.aliprandi@st.com 2:9f389fd8fb2e 274 Z-=SubConst;
davide.aliprandi@st.com 2:9f389fd8fb2e 275
davide.aliprandi@st.com 2:9f389fd8fb2e 276 if(Param->HP_ALFA!= 0)
davide.aliprandi@st.com 2:9f389fd8fb2e 277 {
davide.aliprandi@st.com 2:9f389fd8fb2e 278 OldOut = (Param->HP_ALFA * (OldOut + Z - OldIn))/256;
davide.aliprandi@st.com 2:9f389fd8fb2e 279 OldIn=Z;
davide.aliprandi@st.com 2:9f389fd8fb2e 280 Z=OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 281 }
davide.aliprandi@st.com 2:9f389fd8fb2e 282
davide.aliprandi@st.com 2:9f389fd8fb2e 283 if(Param->LP_ALFA != 0)
davide.aliprandi@st.com 2:9f389fd8fb2e 284 {
davide.aliprandi@st.com 2:9f389fd8fb2e 285 OldZ = ((256-Param->LP_ALFA)*OldZ+Param->LP_ALFA*Z)/256;
davide.aliprandi@st.com 2:9f389fd8fb2e 286 Z = OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 287 }
davide.aliprandi@st.com 2:9f389fd8fb2e 288
davide.aliprandi@st.com 2:9f389fd8fb2e 289 // if(Param->SincN>=3){
davide.aliprandi@st.com 2:9f389fd8fb2e 290 // Z = RoundDiv(Z, DivideConst);
davide.aliprandi@st.com 2:9f389fd8fb2e 291 // Z *= MicGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 292 // }else{
davide.aliprandi@st.com 2:9f389fd8fb2e 293 Z *= MicGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 294 Z = RoundDiv(Z, DivideConst);
davide.aliprandi@st.com 2:9f389fd8fb2e 295 // }
davide.aliprandi@st.com 2:9f389fd8fb2e 296 Z = SaturaLH(Z, -32700, 32700); // saturation
davide.aliprandi@st.com 2:9f389fd8fb2e 297 dataOut[i*Param->Out_MicChannels] = Z ;
davide.aliprandi@st.com 2:9f389fd8fb2e 298 // data+=(Param->Decimation-app)/8 * Param->In_MicChannels;
davide.aliprandi@st.com 2:9f389fd8fb2e 299 data+=Param->byte;
davide.aliprandi@st.com 2:9f389fd8fb2e 300 // data+=Param->Decimation/8*Param->In_MicChannels;
davide.aliprandi@st.com 2:9f389fd8fb2e 301 }
davide.aliprandi@st.com 2:9f389fd8fb2e 302 Param->OldOut=OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 303 Param->OldIn=OldIn;
davide.aliprandi@st.com 2:9f389fd8fb2e 304 Param->OldZ=OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 305 }