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@15:17bdadc6aa9c, 2017-05-02 (annotated)

Committer:
davide.aliprandi@st.com
Date:
Tue May 02 18:06:58 2017 +0200
Revision:
15:17bdadc6aa9c
Parent:
13:90465220b75f
Child:
16:4ab2eac7be21
Improve performance with a LUT (now supports stereo@32KHz).

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 maxVol 64
davide.aliprandi@st.com 2:9f389fd8fb2e 39 #define FilterGain 16;
davide.aliprandi@st.com 2:9f389fd8fb2e 40 #define RoundDiv(a, b) (((a)>0)?(((a)+(b)/2)/(b)):(((a)-(b)/2)/(b)))
davide.aliprandi@st.com 2:9f389fd8fb2e 41 #define SaturaLH(N, L, H) (((N)<(L))?(L):(((N)>(H))?(H):(N)))
davide.aliprandi@st.com 2:9f389fd8fb2e 42
davide.aliprandi@st.com 15:17bdadc6aa9c 43 #define SINCN_MAX 3
davide.aliprandi@st.com 15:17bdadc6aa9c 44 #define DECIMATION_MAX 64
davide.aliprandi@st.com 15:17bdadc6aa9c 45
davide.aliprandi@st.com 2:9f389fd8fb2e 46
davide.aliprandi@st.com 2:9f389fd8fb2e 47 /* Variables -----------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 48
davide.aliprandi@st.com 2:9f389fd8fb2e 49 uint32_t DivideConst = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 50 int64_t SubConst = 0;
davide.aliprandi@st.com 15:17bdadc6aa9c 51 uint32_t sinc1[DECIMATION_MAX];
davide.aliprandi@st.com 15:17bdadc6aa9c 52 uint32_t sinc2[DECIMATION_MAX*2];
davide.aliprandi@st.com 15:17bdadc6aa9c 53 uint32_t sinc3[DECIMATION_MAX*3];
davide.aliprandi@st.com 15:17bdadc6aa9c 54 uint32_t sinc4[DECIMATION_MAX*4];
davide.aliprandi@st.com 15:17bdadc6aa9c 55 uint32_t sinc[DECIMATION_MAX*5];
davide.aliprandi@st.com 2:9f389fd8fb2e 56 int64_t Z = 0;
davide.aliprandi@st.com 15:17bdadc6aa9c 57 uint32_t coef[5][DECIMATION_MAX]; // Max sinc 5 with Param->Decimation = 128.
davide.aliprandi@st.com 15:17bdadc6aa9c 58 #ifdef USE_LUT
davide.aliprandi@st.com 15:17bdadc6aa9c 59 int32_t lut[256][DECIMATION_MAX / 8][SINCN_MAX];
davide.aliprandi@st.com 15:17bdadc6aa9c 60 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 61
davide.aliprandi@st.com 2:9f389fd8fb2e 62
davide.aliprandi@st.com 2:9f389fd8fb2e 63 /* Functions -----------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 64
davide.aliprandi@st.com 15:17bdadc6aa9c 65 int64_t filterTable(uint8_t *data, uint8_t SincN, uint8_t decimation, uint8_t channels);
davide.aliprandi@st.com 2:9f389fd8fb2e 66
davide.aliprandi@st.com 2:9f389fd8fb2e 67 void convolve(uint32_t Signal[/* SignalLen */], unsigned short SignalLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 68 uint32_t Kernel[/* KernelLen */], unsigned short KernelLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 69 uint32_t Result[/* SignalLen + KernelLen - 1 */]);
davide.aliprandi@st.com 2:9f389fd8fb2e 70
davide.aliprandi@st.com 15:17bdadc6aa9c 71 #ifdef USE_LUT
davide.aliprandi@st.com 15:17bdadc6aa9c 72 inline int64_t filterTable(uint8_t *data, uint8_t SincN, uint8_t decimation, uint8_t channels)
davide.aliprandi@st.com 15:17bdadc6aa9c 73 {
davide.aliprandi@st.com 15:17bdadc6aa9c 74 uint8_t c, d;
davide.aliprandi@st.com 15:17bdadc6aa9c 75 uint16_t data_index = 0;
davide.aliprandi@st.com 15:17bdadc6aa9c 76 int64_t F = 0;
davide.aliprandi@st.com 15:17bdadc6aa9c 77
davide.aliprandi@st.com 15:17bdadc6aa9c 78 for (d = 0; d < (decimation >> 3); d++)
davide.aliprandi@st.com 15:17bdadc6aa9c 79 {
davide.aliprandi@st.com 15:17bdadc6aa9c 80 c = data[data_index];
davide.aliprandi@st.com 15:17bdadc6aa9c 81 F += lut[c][d][SincN];
davide.aliprandi@st.com 15:17bdadc6aa9c 82 data_index += channels;
davide.aliprandi@st.com 15:17bdadc6aa9c 83 }
davide.aliprandi@st.com 15:17bdadc6aa9c 84 return F;
davide.aliprandi@st.com 15:17bdadc6aa9c 85 }
davide.aliprandi@st.com 15:17bdadc6aa9c 86 #else
davide.aliprandi@st.com 11:b2f7f79026e4 87 inline int64_t filterTable(uint8_t *data, uint8_t table, uint8_t decimation, uint8_t channels)
davide.aliprandi@st.com 2:9f389fd8fb2e 88 {
Davidroid 13:90465220b75f 89 uint8_t c, i;
davide.aliprandi@st.com 11:b2f7f79026e4 90 uint16_t data_index = 0;
davide.aliprandi@st.com 11:b2f7f79026e4 91 uint32_t *coef_p = &coef[table][0];
davide.aliprandi@st.com 2:9f389fd8fb2e 92 int64_t F = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 93
davide.aliprandi@st.com 11:b2f7f79026e4 94 for (i = 0; i < decimation; i += 8)
davide.aliprandi@st.com 15:17bdadc6aa9c 95 {
davide.aliprandi@st.com 11:b2f7f79026e4 96 c = data[data_index];
davide.aliprandi@st.com 11:b2f7f79026e4 97 F += ((c >> 7) ) * coef_p[i ] +
davide.aliprandi@st.com 11:b2f7f79026e4 98 ((c >> 6) & 0x01) * coef_p[i + 1] +
davide.aliprandi@st.com 11:b2f7f79026e4 99 ((c >> 5) & 0x01) * coef_p[i + 2] +
davide.aliprandi@st.com 11:b2f7f79026e4 100 ((c >> 4) & 0x01) * coef_p[i + 3] +
davide.aliprandi@st.com 11:b2f7f79026e4 101 ((c >> 3) & 0x01) * coef_p[i + 4] +
davide.aliprandi@st.com 11:b2f7f79026e4 102 ((c >> 2) & 0x01) * coef_p[i + 5] +
davide.aliprandi@st.com 11:b2f7f79026e4 103 ((c >> 1) & 0x01) * coef_p[i + 6] +
davide.aliprandi@st.com 11:b2f7f79026e4 104 ((c ) & 0x01) * coef_p[i + 7];
davide.aliprandi@st.com 11:b2f7f79026e4 105 data_index += channels;
davide.aliprandi@st.com 2:9f389fd8fb2e 106 }
davide.aliprandi@st.com 2:9f389fd8fb2e 107 return F;
davide.aliprandi@st.com 2:9f389fd8fb2e 108 }
davide.aliprandi@st.com 15:17bdadc6aa9c 109 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 110
davide.aliprandi@st.com 2:9f389fd8fb2e 111 void Open_PDM_Filter_Init(TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 112 {
davide.aliprandi@st.com 2:9f389fd8fb2e 113 uint16_t i,j;
davide.aliprandi@st.com 2:9f389fd8fb2e 114 int64_t sum = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 115 Param->Coef[0] = Param->Coef[1] = Param->Coef[2] = Param->Coef[3] = Param->Coef[4] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 116 for(i=0;i<5;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 117 {
davide.aliprandi@st.com 2:9f389fd8fb2e 118 Param->bit[i]=0;
davide.aliprandi@st.com 2:9f389fd8fb2e 119 }
davide.aliprandi@st.com 2:9f389fd8fb2e 120
davide.aliprandi@st.com 2:9f389fd8fb2e 121 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 122 {
davide.aliprandi@st.com 2:9f389fd8fb2e 123 sinc1[i]=1;
davide.aliprandi@st.com 2:9f389fd8fb2e 124 }
davide.aliprandi@st.com 2:9f389fd8fb2e 125 Param->OldOut = Param->OldIn = Param->OldZ = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 126 if(Param->LP_HZ!=0)
davide.aliprandi@st.com 2:9f389fd8fb2e 127 {
davide.aliprandi@st.com 2:9f389fd8fb2e 128 Param->LP_ALFA = (uint16_t)(Param->LP_HZ*256 / (Param->LP_HZ + Param->Fs/(2*3.14)));
davide.aliprandi@st.com 2:9f389fd8fb2e 129 }else
davide.aliprandi@st.com 2:9f389fd8fb2e 130 {
davide.aliprandi@st.com 2:9f389fd8fb2e 131 Param->LP_ALFA = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 132 }
davide.aliprandi@st.com 2:9f389fd8fb2e 133
davide.aliprandi@st.com 2:9f389fd8fb2e 134 if(Param->HP_HZ!=0)
davide.aliprandi@st.com 2:9f389fd8fb2e 135 {
davide.aliprandi@st.com 2:9f389fd8fb2e 136 Param->HP_ALFA = (uint16_t)(Param->Fs*256 / (2*3.14*Param->HP_HZ + Param->Fs));
davide.aliprandi@st.com 2:9f389fd8fb2e 137 }else
davide.aliprandi@st.com 2:9f389fd8fb2e 138 {
davide.aliprandi@st.com 2:9f389fd8fb2e 139 Param->HP_ALFA = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 140 }
davide.aliprandi@st.com 2:9f389fd8fb2e 141
davide.aliprandi@st.com 2:9f389fd8fb2e 142 switch(Param->SincN)
davide.aliprandi@st.com 2:9f389fd8fb2e 143 {
davide.aliprandi@st.com 2:9f389fd8fb2e 144 case 1:
davide.aliprandi@st.com 2:9f389fd8fb2e 145 Param->FilterLen = Param->Decimation;
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[0][i]=1;
davide.aliprandi@st.com 2:9f389fd8fb2e 150 sum+= 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 151 }
davide.aliprandi@st.com 2:9f389fd8fb2e 152 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 153 case 2:
davide.aliprandi@st.com 2:9f389fd8fb2e 154 Param->FilterLen = Param->Decimation * 2;
davide.aliprandi@st.com 2:9f389fd8fb2e 155
davide.aliprandi@st.com 2:9f389fd8fb2e 156 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 157
davide.aliprandi@st.com 2:9f389fd8fb2e 158 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,&sinc[1]);
davide.aliprandi@st.com 2:9f389fd8fb2e 159
davide.aliprandi@st.com 2:9f389fd8fb2e 160 for(j=0;j<2;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
davide.aliprandi@st.com 2:9f389fd8fb2e 169 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 170 case 3:
davide.aliprandi@st.com 2:9f389fd8fb2e 171 Param->FilterLen = Param->Decimation * 3;
davide.aliprandi@st.com 2:9f389fd8fb2e 172 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 173 sinc[Param->Decimation*3-1] = 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,&sinc[1]);
davide.aliprandi@st.com 2:9f389fd8fb2e 176 for(j=0;j<3;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 177 {
davide.aliprandi@st.com 2:9f389fd8fb2e 178 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 179 {
davide.aliprandi@st.com 2:9f389fd8fb2e 180 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 181 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 182 }
davide.aliprandi@st.com 2:9f389fd8fb2e 183 }
davide.aliprandi@st.com 2:9f389fd8fb2e 184 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 185 case 4:
davide.aliprandi@st.com 2:9f389fd8fb2e 186 Param->FilterLen = Param->Decimation * 4;
davide.aliprandi@st.com 2:9f389fd8fb2e 187 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 188 sinc[1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 189 sinc[Param->Decimation*4-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 190 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 191 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,sinc3);
davide.aliprandi@st.com 2:9f389fd8fb2e 192 convolve(sinc3, Param->Decimation*3-2,sinc1,Param->Decimation,&sinc[2]);
davide.aliprandi@st.com 2:9f389fd8fb2e 193 for(j=0;j<4;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 194 {
davide.aliprandi@st.com 2:9f389fd8fb2e 195 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 196 {
davide.aliprandi@st.com 2:9f389fd8fb2e 197 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 198 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 199 }
davide.aliprandi@st.com 2:9f389fd8fb2e 200 }
davide.aliprandi@st.com 2:9f389fd8fb2e 201
davide.aliprandi@st.com 2:9f389fd8fb2e 202 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 203 case 5:
davide.aliprandi@st.com 2:9f389fd8fb2e 204 Param->FilterLen = Param->Decimation*5; // Dec * 5 - 2
davide.aliprandi@st.com 2:9f389fd8fb2e 205 sinc[0] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 206 sinc[1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 207 sinc[Param->Decimation*5-2] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 208 sinc[Param->Decimation*5-1] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 209
davide.aliprandi@st.com 2:9f389fd8fb2e 210 convolve(sinc1, Param->Decimation,sinc1,Param->Decimation,sinc2);
davide.aliprandi@st.com 2:9f389fd8fb2e 211 convolve(sinc2, Param->Decimation*2-1,sinc1,Param->Decimation,sinc3);
davide.aliprandi@st.com 2:9f389fd8fb2e 212 convolve(sinc3, Param->Decimation*3-2,sinc1,Param->Decimation,sinc4);
davide.aliprandi@st.com 2:9f389fd8fb2e 213 convolve(sinc4, Param->Decimation*4-3,sinc1,Param->Decimation,&sinc[2]);
davide.aliprandi@st.com 2:9f389fd8fb2e 214
davide.aliprandi@st.com 2:9f389fd8fb2e 215 for(j=0;j<5;j++)
davide.aliprandi@st.com 2:9f389fd8fb2e 216 {
davide.aliprandi@st.com 2:9f389fd8fb2e 217 for(i=0;i<Param->Decimation;i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 218 {
davide.aliprandi@st.com 2:9f389fd8fb2e 219 coef[j][i] = sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 220 sum+= sinc[j*Param->Decimation+i];
davide.aliprandi@st.com 2:9f389fd8fb2e 221 }
davide.aliprandi@st.com 2:9f389fd8fb2e 222 }
davide.aliprandi@st.com 2:9f389fd8fb2e 223 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 224 }
davide.aliprandi@st.com 2:9f389fd8fb2e 225 SubConst = sum / 2;
davide.aliprandi@st.com 2:9f389fd8fb2e 226 DivideConst = SubConst*maxVol/32768/FilterGain;
davide.aliprandi@st.com 15:17bdadc6aa9c 227 if (DivideConst == 0)
davide.aliprandi@st.com 15:17bdadc6aa9c 228 DivideConst = 1;
davide.aliprandi@st.com 15:17bdadc6aa9c 229
davide.aliprandi@st.com 15:17bdadc6aa9c 230 #ifdef USE_LUT
davide.aliprandi@st.com 15:17bdadc6aa9c 231 /* Look-Up Table. */
davide.aliprandi@st.com 15:17bdadc6aa9c 232 uint16_t c, d, s;
davide.aliprandi@st.com 15:17bdadc6aa9c 233 for (s = 0; s < SINCN_MAX; s++)
davide.aliprandi@st.com 15:17bdadc6aa9c 234 {
davide.aliprandi@st.com 15:17bdadc6aa9c 235 uint32_t *coef_p = &coef[s][0];
davide.aliprandi@st.com 15:17bdadc6aa9c 236 for (c = 0; c < 256; c++)
davide.aliprandi@st.com 15:17bdadc6aa9c 237 for (d = 0; d < DECIMATION_MAX / 8; d++)
davide.aliprandi@st.com 15:17bdadc6aa9c 238 lut[c][d][s] = ((c >> 7) ) * coef_p[d * 8 ] +
davide.aliprandi@st.com 15:17bdadc6aa9c 239 ((c >> 6) & 0x01) * coef_p[d * 8 + 1] +
davide.aliprandi@st.com 15:17bdadc6aa9c 240 ((c >> 5) & 0x01) * coef_p[d * 8 + 2] +
davide.aliprandi@st.com 15:17bdadc6aa9c 241 ((c >> 4) & 0x01) * coef_p[d * 8 + 3] +
davide.aliprandi@st.com 15:17bdadc6aa9c 242 ((c >> 3) & 0x01) * coef_p[d * 8 + 4] +
davide.aliprandi@st.com 15:17bdadc6aa9c 243 ((c >> 2) & 0x01) * coef_p[d * 8 + 5] +
davide.aliprandi@st.com 15:17bdadc6aa9c 244 ((c >> 1) & 0x01) * coef_p[d * 8 + 6] +
davide.aliprandi@st.com 15:17bdadc6aa9c 245 ((c ) & 0x01) * coef_p[d * 8 + 7];
davide.aliprandi@st.com 15:17bdadc6aa9c 246 }
davide.aliprandi@st.com 15:17bdadc6aa9c 247 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 248 }
davide.aliprandi@st.com 2:9f389fd8fb2e 249
davide.aliprandi@st.com 2:9f389fd8fb2e 250 void convolve(uint32_t Signal[/* SignalLen */], unsigned short SignalLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 251 uint32_t Kernel[/* KernelLen */], unsigned short KernelLen,
davide.aliprandi@st.com 2:9f389fd8fb2e 252 uint32_t Result[/* SignalLen + KernelLen - 1 */])
davide.aliprandi@st.com 2:9f389fd8fb2e 253 {
davide.aliprandi@st.com 2:9f389fd8fb2e 254 uint16_t n;
davide.aliprandi@st.com 2:9f389fd8fb2e 255 for (n = 0; n < SignalLen + KernelLen - 1; n++)
davide.aliprandi@st.com 2:9f389fd8fb2e 256 {
davide.aliprandi@st.com 2:9f389fd8fb2e 257 unsigned short kmin, kmax, k;
davide.aliprandi@st.com 2:9f389fd8fb2e 258
davide.aliprandi@st.com 2:9f389fd8fb2e 259 Result[n] = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 260
davide.aliprandi@st.com 2:9f389fd8fb2e 261 kmin = (n >= KernelLen - 1) ? n - (KernelLen - 1) : 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 262 kmax = (n < SignalLen - 1) ? n : SignalLen - 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 263
davide.aliprandi@st.com 2:9f389fd8fb2e 264 for (k = kmin; k <= kmax; k++)
davide.aliprandi@st.com 2:9f389fd8fb2e 265 {
davide.aliprandi@st.com 2:9f389fd8fb2e 266 Result[n] += Signal[k] * Kernel[n - k];
davide.aliprandi@st.com 2:9f389fd8fb2e 267 }
davide.aliprandi@st.com 2:9f389fd8fb2e 268 }
davide.aliprandi@st.com 2:9f389fd8fb2e 269 }
davide.aliprandi@st.com 2:9f389fd8fb2e 270
davide.aliprandi@st.com 2:9f389fd8fb2e 271 void Open_PDM_Filter(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, TPDMFilter_InitStruct *Param)
davide.aliprandi@st.com 2:9f389fd8fb2e 272 {
davide.aliprandi@st.com 2:9f389fd8fb2e 273 uint32_t i;
davide.aliprandi@st.com 2:9f389fd8fb2e 274 int64_t OldOut, OldIn, OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 275 OldOut=Param->OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 276 OldIn=Param->OldIn;
davide.aliprandi@st.com 2:9f389fd8fb2e 277 OldZ=Param->OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 278
davide.aliprandi@st.com 2:9f389fd8fb2e 279 for (i = 0; i < Param->Fs/1000; i++)
davide.aliprandi@st.com 2:9f389fd8fb2e 280 {
davide.aliprandi@st.com 2:9f389fd8fb2e 281 switch(Param->SincN)
davide.aliprandi@st.com 2:9f389fd8fb2e 282 {
davide.aliprandi@st.com 2:9f389fd8fb2e 283 case 1:
davide.aliprandi@st.com 11:b2f7f79026e4 284 Z = filterTable(data, 0, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 2:9f389fd8fb2e 285 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 286 case 2:
davide.aliprandi@st.com 11:b2f7f79026e4 287 Z = Param->Coef[0] + filterTable(data, 1, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 288 Param->Coef[0] = filterTable(data, 0, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 2:9f389fd8fb2e 289 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 290 case 3:
davide.aliprandi@st.com 11:b2f7f79026e4 291 Z = Param->Coef[1] + filterTable(data, 2, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 292 Param->Coef[1] = Param->Coef[0] + filterTable(data, 1, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 293 Param->Coef[0] = filterTable(data, 0, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 2:9f389fd8fb2e 294 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 295 case 4:
davide.aliprandi@st.com 11:b2f7f79026e4 296 Z = Param->Coef[2] + filterTable(data, 3, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 297 Param->Coef[2] = Param->Coef[1] + filterTable(data, 2, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 298 Param->Coef[1] = Param->Coef[0] + filterTable(data, 1, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 299 Param->Coef[0] = filterTable(data, 0, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 2:9f389fd8fb2e 300 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 301 case 5:
davide.aliprandi@st.com 11:b2f7f79026e4 302 Z = Param->Coef[3] + filterTable(data, 4, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 303 Param->Coef[3] = Param->Coef[2] + filterTable(data, 3, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 304 Param->Coef[2] = Param->Coef[1] + filterTable(data, 2, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 305 Param->Coef[1] = Param->Coef[0] + filterTable(data, 1, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 11:b2f7f79026e4 306 Param->Coef[0] = filterTable(data, 0, Param->Decimation, Param->In_MicChannels);
davide.aliprandi@st.com 2:9f389fd8fb2e 307 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 308 }
davide.aliprandi@st.com 2:9f389fd8fb2e 309
davide.aliprandi@st.com 11:b2f7f79026e4 310 Z -= SubConst;
davide.aliprandi@st.com 2:9f389fd8fb2e 311
davide.aliprandi@st.com 11:b2f7f79026e4 312 if (Param->HP_ALFA!= 0)
davide.aliprandi@st.com 2:9f389fd8fb2e 313 {
davide.aliprandi@st.com 2:9f389fd8fb2e 314 OldOut = (Param->HP_ALFA * (OldOut + Z - OldIn))/256;
davide.aliprandi@st.com 11:b2f7f79026e4 315 OldIn = Z;
davide.aliprandi@st.com 11:b2f7f79026e4 316 Z = OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 317 }
davide.aliprandi@st.com 2:9f389fd8fb2e 318
davide.aliprandi@st.com 11:b2f7f79026e4 319 if (Param->LP_ALFA != 0)
davide.aliprandi@st.com 2:9f389fd8fb2e 320 {
davide.aliprandi@st.com 2:9f389fd8fb2e 321 OldZ = ((256-Param->LP_ALFA)*OldZ+Param->LP_ALFA*Z)/256;
davide.aliprandi@st.com 2:9f389fd8fb2e 322 Z = OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 323 }
davide.aliprandi@st.com 2:9f389fd8fb2e 324
davide.aliprandi@st.com 2:9f389fd8fb2e 325 // if(Param->SincN>=3){
davide.aliprandi@st.com 2:9f389fd8fb2e 326 // Z = RoundDiv(Z, DivideConst);
davide.aliprandi@st.com 2:9f389fd8fb2e 327 // Z *= MicGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 328 // }else{
davide.aliprandi@st.com 2:9f389fd8fb2e 329 Z *= MicGain;
davide.aliprandi@st.com 2:9f389fd8fb2e 330 Z = RoundDiv(Z, DivideConst);
davide.aliprandi@st.com 2:9f389fd8fb2e 331 // }
davide.aliprandi@st.com 2:9f389fd8fb2e 332 Z = SaturaLH(Z, -32700, 32700); // saturation
davide.aliprandi@st.com 2:9f389fd8fb2e 333 dataOut[i*Param->Out_MicChannels] = Z ;
davide.aliprandi@st.com 11:b2f7f79026e4 334 data += ((Param->Decimation / 8) * Param->In_MicChannels);
davide.aliprandi@st.com 2:9f389fd8fb2e 335 }
davide.aliprandi@st.com 2:9f389fd8fb2e 336 Param->OldOut=OldOut;
davide.aliprandi@st.com 2:9f389fd8fb2e 337 Param->OldIn=OldIn;
davide.aliprandi@st.com 2:9f389fd8fb2e 338 Param->OldZ=OldZ;
davide.aliprandi@st.com 2:9f389fd8fb2e 339 }