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.

Diff: Middlewares/PDM2PCM/pdm_filter.h

Revision:
0:d5552d432108
Child:
2:9f389fd8fb2e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Middlewares/PDM2PCM/pdm_filter.h	Tue Feb 28 11:20:53 2017 +0100
@@ -0,0 +1,76 @@
+/**
+  ******************************************************************************
+  * @file    pdm_filter.h
+  * @author  MCD Application Team
+  * @version V2.0.1
+  * @date    17-December-2013
+  * @brief   Header file for PDM audio software decoding Library.   
+  *          This Library is used to decode and reconstruct the audio signal
+  *          produced by ST MEMS microphone (MP45Dxxx, MP34Dxxx).
+  *          For more details about this Library, please refer to document
+  *          "PDM audio software decoding on STM32 microcontrollers (AN3998)".  
+ ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>
+  *
+  * Licensed under MCD-ST Image SW License Agreement V2, (the "License");
+  * You may not use this file except in compliance with the License.
+  * You may obtain a copy of the License at:
+  *
+  *        http://www.st.com/software_license_agreement_image_v2
+  *
+  * Unless required by applicable law or agreed to in writing, software 
+  * distributed under the License is distributed on an "AS IS" BASIS, 
+  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  * See the License for the specific language governing permissions and
+  * limitations under the License.
+  *
+  ******************************************************************************
+  */
+
+/* Define to prevent recursive inclusion -------------------------------------*/
+#ifndef __PDM_FILTER_H
+#define __PDM_FILTER_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/* Includes ------------------------------------------------------------------*/
+#include <stdint.h>
+
+
+/* Exported types ------------------------------------------------------------*/
+typedef struct {
+  uint16_t Fs;
+  float LP_HZ;
+  float HP_HZ;
+  uint16_t In_MicChannels;
+  uint16_t Out_MicChannels;
+  char InternalFilter[34];
+} PDMFilter_InitStruct;
+
+/* Exported constants --------------------------------------------------------*/
+/* Exported macros -----------------------------------------------------------*/
+#define HTONS(A)  ((((uint16_t)(A) & 0xff00) >> 8) | \
+                   (((uint16_t)(A) & 0x00ff) << 8))
+
+/* Exported functions ------------------------------------------------------- */
+void PDM_Filter_Init(PDMFilter_InitStruct * Filter);
+
+int32_t PDM_Filter_64_MSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
+int32_t PDM_Filter_80_MSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
+int32_t PDM_Filter_128_MSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
+int32_t PDM_Filter_64_LSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
+int32_t PDM_Filter_80_LSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
+int32_t PDM_Filter_128_LSB(uint8_t* data, uint16_t* dataOut, uint16_t MicGain, PDMFilter_InitStruct * Filter);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __PDM_FILTER_H */
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
+