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.

BSP/PDM2PCMAudio.cpp@2:9f389fd8fb2e, 2017-04-21 (annotated)

Committer:
davide.aliprandi@st.com
Date:
Fri Apr 21 10:33:08 2017 +0200
Revision:
2:9f389fd8fb2e
Child:
7:9d6a4a53e640
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 PDM2PCMAudio_class.cpp
davide.aliprandi@st.com 2:9f389fd8fb2e 4 * @author AST / Software Platforms and Cloud
davide.aliprandi@st.com 2:9f389fd8fb2e 5 * @version V1.0
davide.aliprandi@st.com 2:9f389fd8fb2e 6 * @date November 10th, 2016
davide.aliprandi@st.com 2:9f389fd8fb2e 7 * @brief Implementation file for the PDM2PCMAudio conversion library.
davide.aliprandi@st.com 2:9f389fd8fb2e 8 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 9 * @attention
davide.aliprandi@st.com 2:9f389fd8fb2e 10 *
davide.aliprandi@st.com 2:9f389fd8fb2e 11 * <h2><center>&copy; COPYRIGHT(c) 2015 STMicroelectronics</center></h2>
davide.aliprandi@st.com 2:9f389fd8fb2e 12 *
davide.aliprandi@st.com 2:9f389fd8fb2e 13 * Redistribution and use in source and binary forms, with or without modification,
davide.aliprandi@st.com 2:9f389fd8fb2e 14 * are permitted provided that the following conditions are met:
davide.aliprandi@st.com 2:9f389fd8fb2e 15 * 1. Redistributions of source code must retain the above copyright notice,
davide.aliprandi@st.com 2:9f389fd8fb2e 16 * this list of conditions and the following disclaimer.
davide.aliprandi@st.com 2:9f389fd8fb2e 17 * 2. Redistributions in binary form must reproduce the above copyright notice,
davide.aliprandi@st.com 2:9f389fd8fb2e 18 * this list of conditions and the following disclaimer in the documentation
davide.aliprandi@st.com 2:9f389fd8fb2e 19 * and/or other materials provided with the distribution.
davide.aliprandi@st.com 2:9f389fd8fb2e 20 * 3. Neither the name of STMicroelectronics nor the names of its contributors
davide.aliprandi@st.com 2:9f389fd8fb2e 21 * may be used to endorse or promote products derived from this software
davide.aliprandi@st.com 2:9f389fd8fb2e 22 * without specific prior written permission.
davide.aliprandi@st.com 2:9f389fd8fb2e 23 *
davide.aliprandi@st.com 2:9f389fd8fb2e 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
davide.aliprandi@st.com 2:9f389fd8fb2e 25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
davide.aliprandi@st.com 2:9f389fd8fb2e 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
davide.aliprandi@st.com 2:9f389fd8fb2e 27 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
davide.aliprandi@st.com 2:9f389fd8fb2e 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
davide.aliprandi@st.com 2:9f389fd8fb2e 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
davide.aliprandi@st.com 2:9f389fd8fb2e 30 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
davide.aliprandi@st.com 2:9f389fd8fb2e 31 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
davide.aliprandi@st.com 2:9f389fd8fb2e 32 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
davide.aliprandi@st.com 2:9f389fd8fb2e 33 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
davide.aliprandi@st.com 2:9f389fd8fb2e 34 *
davide.aliprandi@st.com 2:9f389fd8fb2e 35 ******************************************************************************
davide.aliprandi@st.com 2:9f389fd8fb2e 36 */
davide.aliprandi@st.com 2:9f389fd8fb2e 37
davide.aliprandi@st.com 2:9f389fd8fb2e 38
davide.aliprandi@st.com 2:9f389fd8fb2e 39 /* Includes ------------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 40
davide.aliprandi@st.com 2:9f389fd8fb2e 41 #include "PDM2PCMAudio.h"
davide.aliprandi@st.com 2:9f389fd8fb2e 42
davide.aliprandi@st.com 2:9f389fd8fb2e 43
davide.aliprandi@st.com 2:9f389fd8fb2e 44 /* Variables -----------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 45
davide.aliprandi@st.com 2:9f389fd8fb2e 46 /* Demux filter. */
davide.aliprandi@st.com 2:9f389fd8fb2e 47 const uint8_t PDM2PCMAudio::_demux_filter[DEMUX_FILTER_SIZE] =
davide.aliprandi@st.com 2:9f389fd8fb2e 48 {
davide.aliprandi@st.com 2:9f389fd8fb2e 49 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x02, 0x03,
davide.aliprandi@st.com 2:9f389fd8fb2e 50 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x02, 0x03,
davide.aliprandi@st.com 2:9f389fd8fb2e 51 0x04, 0x05, 0x04, 0x05, 0x06, 0x07, 0x06, 0x07,
davide.aliprandi@st.com 2:9f389fd8fb2e 52 0x04, 0x05, 0x04, 0x05, 0x06, 0x07, 0x06, 0x07,
davide.aliprandi@st.com 2:9f389fd8fb2e 53 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x02, 0x03,
davide.aliprandi@st.com 2:9f389fd8fb2e 54 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x02, 0x03,
davide.aliprandi@st.com 2:9f389fd8fb2e 55 0x04, 0x05, 0x04, 0x05, 0x06, 0x07, 0x06, 0x07,
davide.aliprandi@st.com 2:9f389fd8fb2e 56 0x04, 0x05, 0x04, 0x05, 0x06, 0x07, 0x06, 0x07,
davide.aliprandi@st.com 2:9f389fd8fb2e 57 0x08, 0x09, 0x08, 0x09, 0x0a, 0x0b, 0x0a, 0x0b,
davide.aliprandi@st.com 2:9f389fd8fb2e 58 0x08, 0x09, 0x08, 0x09, 0x0a, 0x0b, 0x0a, 0x0b,
davide.aliprandi@st.com 2:9f389fd8fb2e 59 0x0c, 0x0d, 0x0c, 0x0d, 0x0e, 0x0f, 0x0e, 0x0f,
davide.aliprandi@st.com 2:9f389fd8fb2e 60 0x0c, 0x0d, 0x0c, 0x0d, 0x0e, 0x0f, 0x0e, 0x0f,
davide.aliprandi@st.com 2:9f389fd8fb2e 61 0x08, 0x09, 0x08, 0x09, 0x0a, 0x0b, 0x0a, 0x0b,
davide.aliprandi@st.com 2:9f389fd8fb2e 62 0x08, 0x09, 0x08, 0x09, 0x0a, 0x0b, 0x0a, 0x0b,
davide.aliprandi@st.com 2:9f389fd8fb2e 63 0x0c, 0x0d, 0x0c, 0x0d, 0x0e, 0x0f, 0x0e, 0x0f,
davide.aliprandi@st.com 2:9f389fd8fb2e 64 0x0c, 0x0d, 0x0c, 0x0d, 0x0e, 0x0f, 0x0e, 0x0f
davide.aliprandi@st.com 2:9f389fd8fb2e 65 };
davide.aliprandi@st.com 2:9f389fd8fb2e 66
davide.aliprandi@st.com 2:9f389fd8fb2e 67
davide.aliprandi@st.com 2:9f389fd8fb2e 68 /* Methods -------------------------------------------------------------------*/
davide.aliprandi@st.com 2:9f389fd8fb2e 69
davide.aliprandi@st.com 2:9f389fd8fb2e 70 /**
davide.aliprandi@st.com 2:9f389fd8fb2e 71 * @brief Converting audio data from PDM to PCM.
davide.aliprandi@st.com 2:9f389fd8fb2e 72 * @param output_buffer Pointer to output PCM buffer data.
davide.aliprandi@st.com 2:9f389fd8fb2e 73 * @param input_buffer Pointer to input PDM buffer data.
davide.aliprandi@st.com 2:9f389fd8fb2e 74 * @param volume Volume level (it must be in the range [0..64]).
davide.aliprandi@st.com 2:9f389fd8fb2e 75 * @param decimation_factor Decimation factor (it must be either 64 or 128).
davide.aliprandi@st.com 2:9f389fd8fb2e 76 * @retval COMPONENT_OK in case of success, COMPONENT_ERROR otherwise.
davide.aliprandi@st.com 2:9f389fd8fb2e 77 */
davide.aliprandi@st.com 2:9f389fd8fb2e 78 status_t PDM2PCMAudio::convert(int16_t *output_buffer, uint16_t *input_buffer, uint32_t volume, uint32_t decimation_factor)
davide.aliprandi@st.com 2:9f389fd8fb2e 79 {
davide.aliprandi@st.com 2:9f389fd8fb2e 80 if (!(volume <= PDM2PCM_MAX_VOLUME))
davide.aliprandi@st.com 2:9f389fd8fb2e 81 error("Volume level not supported: it must be in the range [0..64].\r\n");
davide.aliprandi@st.com 2:9f389fd8fb2e 82
davide.aliprandi@st.com 2:9f389fd8fb2e 83 switch (decimation_factor)
davide.aliprandi@st.com 2:9f389fd8fb2e 84 {
davide.aliprandi@st.com 2:9f389fd8fb2e 85 case 64:
davide.aliprandi@st.com 2:9f389fd8fb2e 86 for (uint32_t index = 0; index < 1/*_channels*/; index++) {
davide.aliprandi@st.com 2:9f389fd8fb2e 87 #ifdef PDM2PCM_AUDIO_DEBUG
davide.aliprandi@st.com 2:9f389fd8fb2e 88 _pdm2pcm_audio_signal = 1;
davide.aliprandi@st.com 2:9f389fd8fb2e 89 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 90 #ifdef USE_OPEN_PDM2PCM_LIBRARY
davide.aliprandi@st.com 2:9f389fd8fb2e 91 Open_PDM_Filter(&((uint8_t *) input_buffer)[index], (uint16_t *) &(output_buffer[index]), volume, (TPDMFilter_InitStruct *) &_PDM2PCM_filter[index]);
davide.aliprandi@st.com 2:9f389fd8fb2e 92 #else
davide.aliprandi@st.com 2:9f389fd8fb2e 93 PDM_Filter_64_LSB(&((uint8_t *) input_buffer)[index], (uint16_t *) &(output_buffer[index]), volume, (PDMFilter_InitStruct *) &_PDM2PCM_filter[index]);
davide.aliprandi@st.com 2:9f389fd8fb2e 94 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 95 #ifdef PDM2PCM_AUDIO_DEBUG
davide.aliprandi@st.com 2:9f389fd8fb2e 96 _pdm2pcm_audio_signal = 0;
davide.aliprandi@st.com 2:9f389fd8fb2e 97 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 98 }
davide.aliprandi@st.com 2:9f389fd8fb2e 99 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 100
davide.aliprandi@st.com 2:9f389fd8fb2e 101 case 128:
davide.aliprandi@st.com 2:9f389fd8fb2e 102 for (uint32_t index = 0; index < _channels; index++) {
davide.aliprandi@st.com 2:9f389fd8fb2e 103 #ifdef USE_OPEN_PDM2PCM_LIBRARY
davide.aliprandi@st.com 2:9f389fd8fb2e 104 Open_PDM_Filter(&((uint8_t *) input_buffer)[index], (uint16_t *) &(output_buffer[index]), volume, (TPDMFilter_InitStruct *) &_PDM2PCM_filter[index]);
davide.aliprandi@st.com 2:9f389fd8fb2e 105 #else
davide.aliprandi@st.com 2:9f389fd8fb2e 106 PDM_Filter_128_LSB(&((uint8_t *) input_buffer)[index], (uint16_t *) &(output_buffer[index]), volume, (PDMFilter_InitStruct *) &_PDM2PCM_filter[index]);
davide.aliprandi@st.com 2:9f389fd8fb2e 107 #endif
davide.aliprandi@st.com 2:9f389fd8fb2e 108 }
davide.aliprandi@st.com 2:9f389fd8fb2e 109 break;
davide.aliprandi@st.com 2:9f389fd8fb2e 110
davide.aliprandi@st.com 2:9f389fd8fb2e 111 default:
davide.aliprandi@st.com 2:9f389fd8fb2e 112 error("Decimation factor not supported: it must be either 64 or 128.\r\n");
davide.aliprandi@st.com 2:9f389fd8fb2e 113 }
davide.aliprandi@st.com 2:9f389fd8fb2e 114
davide.aliprandi@st.com 2:9f389fd8fb2e 115 return COMPONENT_OK;
davide.aliprandi@st.com 2:9f389fd8fb2e 116 }
davide.aliprandi@st.com 2:9f389fd8fb2e 117
davide.aliprandi@st.com 2:9f389fd8fb2e 118 /**
davide.aliprandi@st.com 2:9f389fd8fb2e 119 * @brief Scrambling audio data.
davide.aliprandi@st.com 2:9f389fd8fb2e 120 * @param output_buffer Pointer to output PDM buffer data.
davide.aliprandi@st.com 2:9f389fd8fb2e 121 * @param input_buffer Pointer to input PDM buffer data.
davide.aliprandi@st.com 2:9f389fd8fb2e 122 * @param size Size of the buffers (thay has to be equally sized).
davide.aliprandi@st.com 2:9f389fd8fb2e 123 * @retval COMPONENT_OK in case of success, COMPONENT_ERROR otherwise.
davide.aliprandi@st.com 2:9f389fd8fb2e 124 */
davide.aliprandi@st.com 2:9f389fd8fb2e 125 status_t PDM2PCMAudio::scramble(uint16_t *output_buffer, uint16_t *input_buffer, uint32_t size)
davide.aliprandi@st.com 2:9f389fd8fb2e 126 {
davide.aliprandi@st.com 2:9f389fd8fb2e 127 for (uint32_t index = 0; index < size; index++) {
davide.aliprandi@st.com 2:9f389fd8fb2e 128 output_buffer[index] = HTONS(input_buffer[index]);
davide.aliprandi@st.com 2:9f389fd8fb2e 129 }
davide.aliprandi@st.com 2:9f389fd8fb2e 130
davide.aliprandi@st.com 2:9f389fd8fb2e 131 return COMPONENT_OK;
davide.aliprandi@st.com 2:9f389fd8fb2e 132 }
davide.aliprandi@st.com 2:9f389fd8fb2e 133
davide.aliprandi@st.com 2:9f389fd8fb2e 134 /**s
davide.aliprandi@st.com 2:9f389fd8fb2e 135 * @brief Demuxing audio data.
davide.aliprandi@st.com 2:9f389fd8fb2e 136 * @param output_buffer Pointer to output PDM buffer data.
davide.aliprandi@st.com 2:9f389fd8fb2e 137 * @param input_buffer Pointer to input PDM buffer data.
davide.aliprandi@st.com 2:9f389fd8fb2e 138 * @param size Size of the buffers (thay has to be equally sized).
davide.aliprandi@st.com 2:9f389fd8fb2e 139 * @retval COMPONENT_OK in case of success, COMPONENT_ERROR otherwise.
davide.aliprandi@st.com 2:9f389fd8fb2e 140 */
davide.aliprandi@st.com 2:9f389fd8fb2e 141 status_t PDM2PCMAudio::demux(uint16_t *output_buffer, uint16_t *input_buffer, uint32_t size)
davide.aliprandi@st.com 2:9f389fd8fb2e 142 {
davide.aliprandi@st.com 2:9f389fd8fb2e 143 for (uint32_t index = 0; index < size; index++) {
davide.aliprandi@st.com 2:9f389fd8fb2e 144 uint8_t a = ((uint8_t *) input_buffer)[index * 2];
davide.aliprandi@st.com 2:9f389fd8fb2e 145 uint8_t b = ((uint8_t *) input_buffer)[index * 2 + 1];
davide.aliprandi@st.com 2:9f389fd8fb2e 146 ((uint8_t *) (output_buffer))[index * 2] = _demux_filter[a & DEMUX_FILTER_MASK] | _demux_filter[b & DEMUX_FILTER_MASK] << 4;
davide.aliprandi@st.com 2:9f389fd8fb2e 147 ((uint8_t *) (output_buffer))[index * 2 + 1] = _demux_filter[(a >> 1) & DEMUX_FILTER_MASK] | _demux_filter[(b >> 1) & DEMUX_FILTER_MASK] << 4;
davide.aliprandi@st.com 2:9f389fd8fb2e 148 }
davide.aliprandi@st.com 2:9f389fd8fb2e 149
davide.aliprandi@st.com 2:9f389fd8fb2e 150 return COMPONENT_OK;
davide.aliprandi@st.com 2:9f389fd8fb2e 151 }
davide.aliprandi@st.com 2:9f389fd8fb2e 152
davide.aliprandi@st.com 2:9f389fd8fb2e 153 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/