ST / Mbed 2 deprecated HelloWorld_CCA02M1

Simple test application for the STMicroelectronics X-NUCLEO-CCA02M1 MEMS Microphones Expansion Board, built against mbed classic.

Dependencies:   X_NUCLEO_CCA02M1 mbed ST_Events-old

Fork of HelloWorld_CCA02M1_mbedOS by ST

Recording audio with the X-NUCLEO-CCA02M1 Expansion Board

This application provides a simple example of usage of the X-NUCLEO-CCA02M1 MEMS Microphones Expansion Board, built against mbed classic 2.x.

It shows how to record a 2-channel stereo signal as an array of PCM samples (16 bit/sample) that can be acquired through an audio SW like Audacity, for example.

Microphones configuration

Currently the configurations supported are the following:

  • Stereo@48KHz
  • Stereo@44.1KHz (default, 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.
  • Please note that the main application makes use of the "events" library (i.e. the "ST_Events" library imported as "events" library), which is not included into the "mbed" library.
  • The application built against mbed OS can be found here.


Acquiring through the USB on Windows

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.
On Windows, click on the speaker icon on the bottom bar, select "Recording devices", "Microphone", "Properties", then click on the "Advanced" panel, and select "1/2 channels, 16 bit, 16/32KHz" according to board configuration.
Open your preferred audio SW, like "Audacity" for example, configure it to acquire a 2-channel stereo at 16KHz (for default configuration), and record.

main.cpp

Committer:
Davidroid
Date:
2017-04-21
Revision:
1:373c6af58108
Parent:
0:7d07f4df31e1
Child:
7:760d8e527b67

File content as of revision 1:373c6af58108:

/**
 ******************************************************************************
 * @file    main.cpp
 * @author  Davide Aliprandi, STMicroelectronics
 * @version V1.0.0
 * @date    October 28th, 2016
 * @brief   mbed test application for the STMicroelectronics X-NUCLEO-CCA02M1
 *          MEMS Microphones Expansion Board.
 ******************************************************************************
 * @attention
 *
 * <h2><center>&copy; COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *   1. Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *   2. Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *   3. Neither the name of STMicroelectronics nor the names of its contributors
 *      may be used to endorse or promote products derived from this software
 *      without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************
 */


/* Includes ------------------------------------------------------------------*/

/* mbed specific header files. */
#include "mbed.h"
#include "rtos.h"


#if DEVICE_I2S

/* Expansion Board specific header files. */
#include "XNucleoCCA02M1.h"


/* Variables -----------------------------------------------------------------*/

/* Initialization parameters. */
XNucleoCCA02M1_init_t init =
{
	16000,   /* Default Sampling Frequency [Hz]. */
    2        /* Default number of channels. */
};

/* Thread to manage I2S peripherals. */
static rtos::Thread i2s_bh_daemon;


/* Functions -----------------------------------------------------------------*/

/**
 * @brief  Entry point function of mbedOS.
 * @param  None
 * @retval None
 */
int main(void)
{
    /*----- Initialization. -----*/

    /* Initializing MEMS Microphones Expansion Board on the I2S1 interface. */
    XNucleoCCA02M1 *microphones = new XNucleoCCA02M1(PB_15, PB_13);
    if (microphones->init(&init) != COMPONENT_OK)
    {
        error("Initialization of the MEMS Microphones Expansion Board failed.\r\n");
        exit(EXIT_FAILURE);
    }

    /* Starting a thread to manage I2S peripherals. */
    Callback<void()> i2s_bh_task(&I2S::i2s_bh_queue, &events::EventQueue::dispatch_forever);
    i2s_bh_daemon.start(i2s_bh_task);

    /* Enabling transmission via USB. */
    microphones->enable_usb();

    /* Printing to the console. */
    printf("MEMS Microphones Application Example\r\n\n");


    /*----- Recording. -----*/

    /* Printing to the console. */
    printf("--> Recording...\r\n");
    microphones->record();
}

#else // DEVICE_I2S

int main(void)
{
    printf("The target does not support I2S API.\r\n");
}

#endif // DEVICE_I2S