PSOC™ 6 MCU: XENSIV™ microphone audio shield stereo

This code example demonstrates the usage of Infineon's XENSIV™ Audio Shield to connect up to two analog or digital microphones to a PC via USB. It is designed to evaluate the performance of XENSIV™ MEMS microphones in array applications and serves as a foundation for audio processing use cases. Host systems can use the device as a stereo channel audio input for development in environments, such as MATLAB®, Python, and others.

It offers a reference implementation for audio data acquisition, processing, and USB streaming using I2S and DMA, facilitating rapid prototyping and extension for advanced audio applications. The project is intended for research, prototyping, and product development in embedded audio and acoustics.

View this README on GitHub.

Provide feedback on this code example.

Requirements

• ModusToolbox™ v3.5 or later (tested with v3.5)
• Board support package (BSP) minimum required version: 4.0.0
• Programming language: C
• XENSIV™ Audio Shield
• Two analog or two digital Infineon's XENSIV™ MEMS microphones on flex, such as:
  • KIT-IM72D128V01-FLEX
  • KIT-IM73A135V01-FLEX
• Two Micro USB cables
• Additional 12v DC Power supply(if required)
• Audio software such as Audacity, Python, MATLAB®, or others
• Associated parts: All PSOC™ 6 MCU parts

Supported toolchains (make variable 'TOOLCHAIN')

• GNU Arm® Embedded Compiler v11.3.1 (GCC_ARM) – Default value of TOOLCHAIN
• Arm® Compiler v6.22 (ARM)
• IAR C/C++ Compiler v9.50.2 (IAR)

Supported kits (make variable 'TARGET')

• PSOC™ 62S2 Evaluation Kit (CY8CEVAL-062S2) – Default value of TARGET
• PSOC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit (CY8CKIT-062S2-43012)

Features

• USB Audio Class 2.0 compliant, supporting stereo channel microphone data at 48 kHz and 24-bit resolution
• Compatible with Audacity and WASAPI for multi-channel recording
• Efficient use of DMA to offload CPU, enabling real-time algorithms on PSOC™ 6 MCU
• Modular firmware structure for easy extension and integration

Hardware setup

XENSIV™ Audio Shield with PSOC™ 62S2 Evaluation Kit

The XENSIV™ PSOC™ 62S2 Evaluation Kit enables you to evaluate and develop your applications using the PSOC™ 62 series MCU (hereafter called “PSOC™ 6 MCU”) and connectivity modules based on AIROC™ Wi-Fi & Bluetooth® combo chip.

• PSOC™ 62S2 Evaluation Kit (CY8CEVAL-062S2)

  Figure 1. PSOC™ 62S2 Evaluation Kit

  

• XENSIV™ Audio Shield

  Figure 2. Audio Shield

  

• XENSIV™ Audio Shield + PSOC™ 62S2 Evaluation Kit

  Figure 3. Audio Shield + PSOC™ 62S2 Evaluation Kit

  

Set up the kit:

1. Connect two XENSIV™ MEMS microphones to XENSIV™ Audio Shield

2. Ensure that XENSIV™ Audio Shield is mounted on the top of the CY8CEVAL-062S2 kit through the pin headers

3. Connect the PSOC™ 62S2 Evaluation Kit to your PC using two Micro USB cables to power the MCU and shield:

   • Connect the first cable to the MCU USB port
   • Connect the second cable to the KitProg USB port

4. Press the XRES reset pin

XENSIV™ Audio Shield with PSOC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit (CY8CKIT-062S2-43012)

The XENSIV™ PSOC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit (CY8CEVAL-062S2-43012) enables you to evaluate and develop your applications using the PSOC™ 6 MCU and AIROC™CYW43012 Wi-Fi & Bluetooth® combo device

• PSOC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit CY8CEVAL-062S2-43012(https://github.com/Infineon/TARGET_CY8CKIT-062S2-43012)

  Figure 4. Evaluation Kit PSOC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit

  

• XENSIV™ Audio Shield

  Figure 5. XENSIV™ Audio Shield

  

• XENSIV™ Audio Shield + PSOC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit

  Figure 6. XENSIV™ Audio Shield + PSOC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit

  

Set up the kit:

1. Connect two XENSIV™ MEMS microphones to XENSIV™ Audio Shield

2. Ensure that XENSIV™ Audio Shield is mounted on the top of the CY8CEVAL-062S2-43012 kit through the pin headers

3. Connect the PSOC™ 62S2 Evaluation Kit to your PC using two micro USB cables to power the MCU and shield:

   • Connect the first cable to the MCU USB port
   • Connect the second cable to the KitProg USB port

4. Press the XRES reset pin

Note:

1. When connecting the Audio Shield to the evaluation kit, follow this connection sequence to prevent power issues:
   a. Connect the MCU USB (or Device USB) and then connect the KitProg USB
   b. Press the XRES button to reset the board and ensure the power LED is on

2. At times it was also seen that the power supplied from the USB port is not sufficient to power both evaluation board and shield.In that case please use the additional DC Power supply as follows
   a. First connect the evaluation kit using the kitprog USB and program the kit (once programmed please remove the kitprog USB).
   b. Then, connect the DC power supply to the J5 jack on the evaluation board.
   c. Connect the USB cable to the "MCU USB" port.

3. The PSOC™ 6 Bluetooth® LE Pioneer Kit (CY8CKIT-062-BLE) and the PSOC™ 6 Wi-Fi Bluetooth® Pioneer Kit (CY8CKIT-062-WIFI-BT) ship with KitProg2 installed. ModusToolbox™ requires KitProg3. Before using this code example, make sure that the board is upgraded to KitProg3. The tool and instructions are available in the Firmware Loader GitHub repository. If you do not upgrade, you will see an error like "unable to find CMSIS-DAP device" or "KitProg firmware is out of date"

Software setup

See the ModusToolbox™ tools package installation guide for information about installing and configuring the tools package.

Install software for recording audio through USB. For instance, this code example uses Audacity and follows the High-quality audio recording in Windows with Audiohub Nano document.

This example requires no additional software or tools.

Using the code example

Create the project

The ModusToolbox™ tools package provides the Project Creator as both a GUI tool and a command line tool.

Use Project Creator GUI

1. Open the Project Creator GUI tool

   There are several ways to do this, including launching it from the dashboard or from inside the Eclipse IDE. For more details, see the Project Creator user guide (locally available at {ModusToolbox™ install directory}/tools_{version}/project-creator/docs/project-creator.pdf)

2. On the Choose Board Support Package (BSP) page, select a kit supported by this code example. See Supported kits

   Note: To use this code example for a kit not listed here, you may need to update the source files. If the kit does not have the required resources, the application may not work

3. On the Select Application page:

   a. Select the Applications(s) Root Path and the Target IDE

   Note: Depending on how you open the Project Creator tool, these fields may be pre-selected for you

   b. Select this code example from the list by enabling its check box

   Note: You can narrow the list of displayed examples by typing in the filter box

   c. (Optional) Change the suggested New Application Name and New BSP Name

   d. Click Create to complete the application creation process

Use Project Creator CLI

The 'project-creator-cli' tool can be used to create applications from a CLI terminal or from within batch files or shell scripts. This tool is available in the {ModusToolbox™ install directory}/tools_{version}/project-creator/ directory.

Use a CLI terminal to invoke the 'project-creator-cli' tool. On Windows, use the command-line 'modus-shell' program provided in the ModusToolbox™ installation instead of a standard Windows command-line application. This shell provides access to all ModusToolbox™ tools. You can access it by typing "modus-shell" in the search box in the Windows menu. In Linux and macOS, you can use any terminal application.

The following example clones the "Audio Shield two-channel microphone" application with the desired name "2ChannelMic" configured for the CY8CEVAL-062S2 BSP into the specified working directory, C:/mtb_projects:

project-creator-cli --board-id CY8CEVAL-062S2 --app-id mtb-mtb-example-ce242117-xensiv-microphone-audioshield-stereo --user-app-name 2ChannelMic--target-dir "C:/mtb_projects"

The 'project-creator-cli' tool has the following arguments:

Argument	Description	Required/optional
--board-id	Defined in the field of the BSP manifest	Required
--app-id	Defined in the field of the CE manifest	Required
--target-dir	Specify the directory in which the application is to be created if you prefer not to use the default current working directory	Optional
--user-app-name	Specify the name of the application if you prefer to have a name other than the example's default name	Optional

Note: The project-creator-cli tool uses the git clone and make getlibs commands to fetch the repository and import the required libraries. For details, see the "Project creator tools" section of the ModusToolbox™ tools package user guide (locally available at {ModusToolbox™ install directory}/docs_{version}/mtb_user_guide.pdf).

Open the project

After the project has been created, you can open it in your preferred development environment.

Eclipse IDE

If you opened the Project Creator tool from the included Eclipse IDE, the project will open in Eclipse automatically.

For more details, see the Eclipse IDE for ModusToolbox™ user guide (locally available at {ModusToolbox™ install directory}/docs_{version}/mt_ide_user_guide.pdf).

Visual Studio (VS) Code

Launch VS Code manually, and then open the generated {project-name}.code-workspace file located in the project directory.

For more details, see the Visual Studio Code for ModusToolbox™ user guide (locally available at {ModusToolbox™ install directory}/docs_{version}/mt_vscode_user_guide.pdf).

Arm® Keil® µVision®

Double-click the generated {project-name}.cprj file to launch the Keil® µVision® IDE.

For more details, see the Arm® Keil® µVision® for ModusToolbox™ user guide (locally available at {ModusToolbox™ install directory}/docs_{version}/mt_uvision_user_guide.pdf).

IAR Embedded Workbench

Open IAR Embedded Workbench manually, and create a new project. Then select the generated {project-name}.ipcf file located in the project directory.

For more details, see the IAR Embedded Workbench for ModusToolbox™ user guide (locally available at {ModusToolbox™ install directory}/docs_{version}/mt_iar_user_guide.pdf).

Command line

If you prefer to use the CLI, open the appropriate terminal, and navigate to the project directory. On Windows, use the command-line 'modus-shell' program; on Linux and macOS, you can use any terminal application. From there, you can run various make commands.

For more details, see the ModusToolbox™ tools package user guide (locally available at {ModusToolbox™ install directory}/docs_{version}/mtb_user_guide.pdf).

Operation

XENSIV™Microphone Audio Shield Stereo

1. Open the Makefile

2. Select the microphone type (digital or analog):

   • DEFINES+=DIGITAL_BOARD for two digital microphones
   • DEFINES+=ANALOG_BOARD for two analog microphones
   • DEFINES+=ENABLE_HEADPHONES to enable headphone output

3. Save the file and close

4. Program the board using one of the following:

   Using Eclipse IDE

   1. Select the application project in the Project Explorer

   2. In the Quick Panel, scroll down, and click <Application Name> Program (KitProg3_MiniProg4)

   In other IDEs

   Follow the instructions in your preferred IDE.

   Using CLI

   From the terminal, execute the make program command to build and program the application using the default toolchain to the default target. The default toolchain is specified in the application's Makefile but you can override this value manually:

   make program TOOLCHAIN=<toolchain>
   

   Example:

   make program TOOLCHAIN=GCC_ARM
   

5. Open any audio recorder or editor. For instance, you can either use any Python scripts or software such as Audacity. For testing this code example, Audacity is used. Use the High-quality audio recording in Windows with Audiohub Nano document to get more insights on how to use the software

Note:
a. For testing we have used Audacity 3.7.5
b. Kindly note the actual device name will be different to what has been shown in the application note.The actual name of the shield is XENSIV Audioshield and will be displayed in audicity as follows

Figure 7. Audacity

6. To achieve low latency and high sample frequencies in Audacity, it is recommended to use drivers, such as WASAPI or ASIO. When selecting WASAPI, ensure to set up all four available channels to optimize your audio setup and take full advantage of the driver's capabilities

Design and implementation

Details

This project is organized into modular components:

• periph_i2s.c: Configures and manages I2S peripherals and DMA for audio data transfer

• usb_audio.c: Implements the USB audio endpoints and streaming logic

• audioShield.c: Initializes the XENSIV™ Audio Shield via I2C and supports additional hardware features

• rtos: Coordinates real-time tasks and event handling

• usb_comm.c: Handles general USB requests and device enumeration

• main.c: Initializes the board, creates RTOS tasks, and starts the scheduler

• Makefile: Selects voltage and codec settings for digital or analog microphones

For further details, see the Audio Shield user guide and mtb-example-ce242117-xensiv-microphone-audioshield-stereo > doc > dataflow_draft.pptx.

USB audio flow

• Microphones are connected via codec and I2S bus to PSOC™ 6 MCU

• I2S is handled via PSOC™ I2S Rx peripheral and triggers DMA to copy data from the I2S Rx FIFO into the software buffer

• If no active USB audio recording is running, the microphone data is forwarded to headphones via the I2S Tx peripheral

• I2S Rx and Tx share the same clock

• This is USB Audio 2 compliant

• Headphone audio data frame is processed within ISR

• See comments in src > periph_i2s.c file for an overview of interleaved audio data alignment

• For further processing, it is recommended to reduce the ISR load and move data processing into a dedicated RTOS task

System overview

Figure 7. System overview

USB audio data flow

Figure 8. USB audio data flow

Related resources

Resources	Links
Application notes	AN228571 – Getting started with PSOC™ 6 MCU on ModusToolbox™ AN215656 – PSOC™ 6 MCU: Dual-CPU system design AN091404 – High-quality audio recording in Windows with Audiohub Nano
User guide	UG095149 – Audiohub Nano Digital
Code examples	Using ModusToolbox™ on GitHub
Device documentation	PSOC™ 6 MCU datasheets PSOC™ 6 technical reference manuals
Development kits	Select your kits from the Evaluation board finder
Libraries on GitHub	mtb-pdl-cat1 – PSOC™ 6 Peripheral Driver Library (PDL) mtb-hal-cat1 – Hardware Abstraction Layer (HAL) library retarget-io – Utility library to retarget STDIO messages to a UART port
Middleware on GitHub	psoc6-middleware – Links to all PSOC™ 6 MCU middleware
Tools	ModusToolbox™ – ModusToolbox™ software is a collection of easy-to-use libraries and tools enabling rapid development with Infineon MCUs for applications ranging from wireless and cloud-connected systems, edge AI/ML, embedded sense and control, to wired USB connectivity using PSOC™ Industrial/IoT MCUs, AIROC™ Wi-Fi and Bluetooth® connectivity devices, XMC™ Industrial MCUs, and EZ-USB™/EZ-PD™ wired connectivity controllers. ModusToolbox™ incorporates a comprehensive set of BSPs, HAL, libraries, configuration tools, and provides support for industry-standard IDEs to fast-track your embedded application development

Other resources

Infineon provides a wealth of data at www.infineon.com to help you select the right device, and quickly and effectively integrate it into your design.

For more information about connected sensor kits, see IoT sensor platform.

Document history

Document title: CE241889 – PSOC™ 6 MCU: XENSIV™ microphone audio shield stereo

Version	Description of change
1.0.0	New code example

All referenced product or service names and trademarks are the property of their respective owners.

The Bluetooth® word mark and logos are registered trademarks owned by Bluetooth SIG, Inc., and any use of such marks by Infineon is under license.

PSOC™, formerly known as PSoC™, is a trademark of Infineon Technologies. Any references to PSoC™ in this document or others shall be deemed to refer to PSOC™.

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