This example demonstrates how to use the I2S hardware block in PSoC™ 6 MCU to interface with an audio codec.
This code example shows how to play a short audio clip on a speaker or headphones. The application stores the audio data in flash memory. This data is written to the output TX FIFO of the I2S hardware block, which interfaces with an audio codec chip.
The audio codec chip converts a digital audio stream into an analog. The chip is configured by PSoC™ 6 MCU over an I2C interface. The code example includes the audio-codec-ak4954a library which provides the mtb_ak4954a.c/h files that wrap the configuration of the audio codec used in this example.
Figure 1. Block diagram
Provide feedback on this code example.
- ModusToolbox™ software v3.0 or later (tested with v3.0)
- Board support package (BSP) minimum required version: 4.0.0
- Programming language: C
- Associated parts: All PSoC™ 6 MCU parts, AIROC™ CYW20735 Bluetooth® & Bluetooth® LE system on chip, AIROC™ CYW20819 Bluetooth® & Bluetooth® LE system on chip, AIROC™ CYW43012 Wi-Fi & Bluetooth® combo chip, AIROC™ CYW4343W Wi-Fi & Bluetooth® combo chip, AIROC™ CYW4373 Wi-Fi & Bluetooth® combo chip, AIROC™ CYW43439 Wi-Fi & Bluetooth® combo chip
- GNU Arm® embedded compiler v10.3.1 (
GCC_ARM) - Default value ofTOOLCHAIN - Arm® compiler v6.16 (
ARM) - IAR C/C++ compiler v9.30.1 (
IAR)
- PSoC™ 6 Wi-Fi Bluetooth® Prototyping Kit (
CY8CPROTO-062-4343W) - PSoC™ 6 Wi-Fi Bluetooth® Pioneer Kit (
CY8CKIT-062-WIFI-BT) – Default value ofTARGET - PSoC™ 6 Bluetooth® LE Pioneer Kit (
CY8CKIT-062-BLE) - PSoC™ 62S2 Wi-Fi Bluetooth® Pioneer Kit (
CY8CKIT-062S2-43012) - PSoC™ 62S1 Wi-Fi Bluetooth® Pioneer Kit (
CYW9P62S1-43438EVB-01) - PSoC™ 62S1 Wi-Fi Bluetooth® Pioneer Kit (
CYW9P62S1-43012EVB-01) - PSoC™ 64 "Secure Boot" Wi-Fi Bluetooth® Pioneer Kit (
CY8CKIT-064B0S2-4343W) - PSoC™ 62S2 Evaluation Kit (
CY8CEVAL-062S2,CY8CEVAL-062S2-LAI-4373M2,CY8CEVAL-062S2-MUR-43439M2,CY8CEVAL-062S2-LAI-43439M2,CY8CEVAL-062S2-MUR-4373EM2) - PSoC™ 6 Bluetooth® LE prototyping kit (
CY8CPROTO-063-BLE)
This code example requires the TFT display shield board CY8CKIT-028-TFT, which has the audio codec. This board comes with CY8CKIT-062-WiFi-BT. It can also be purchased standalone and be used with any other Arduino-compatible PSoC™ 6 MCU kit.
Alternatively, you can use a third-party module - Pmod I2S2: Stereo audio input and output if you are using a prototyping kit, similar to CY8CPROTO-062-4343W.
If using the Pmod I2S2 module, make the following connections:
| I2S signal | Kit pin | Pmod IS2S pin |
|---|---|---|
| TX_SCK | P5[1] | J1.3 |
| TX_DATA | P5[3] | J1.4 |
| TX_WS | P5[2] | J1.2 |
| MCLK | P5[0] | J1.1 |
| GND | GND | GND |
| VCC | VTARG | VCC |
Note: If using CY8CPROTO-062-4343W, you can solder the Pmod I2S2 module to the kit's Pmod header J15.
Note: If using CY8CPROTO-063-BLE, you can use jumper wires to connect the Pmod I2S2 module to the kit's header J2.
Note: 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. The ModusToolbox™ software 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".
This example requires no additional software or tools.
Create the project and open it using one of the following:
In Eclipse IDE for ModusToolbox™ software
-
Click the New Application link in the Quick Panel (or, use File > New > ModusToolbox™ Application). This launches the Project Creator tool.
-
Pick a kit supported by the code example from the list shown in the Project Creator - Choose Board Support Package (BSP) dialog.
When you select a supported kit, the example is reconfigured automatically to work with the kit. To work with a different supported kit later, use the Library Manager to choose the BSP for the supported kit. You can use the Library Manager to select or update the BSP and firmware libraries used in this application. To access the Library Manager, click the link from the Quick Panel.
You can also just start the application creation process again and select a different kit.
If you want to use the application 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.
-
In the Project Creator - Select Application dialog, choose the example by enabling the checkbox.
-
(Optional) Change the suggested New Application Name.
-
The Application(s) Root Path defaults to the Eclipse workspace which is usually the desired location for the application. If you want to store the application in a different location, you can change the Application(s) Root Path value. Applications that share libraries should be in the same root path.
-
Click Create to complete the application creation process.
For more details, see the Eclipse IDE for ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mt_ide_user_guide.pdf).
In command-line interface (CLI)
ModusToolbox™ software provides the Project Creator as both a GUI tool and the command line tool, "project-creator-cli". The 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™ software 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™ software installation instead of a standard Windows command-line application. This shell provides access to all ModusToolbox™ software 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 "project-creator-cli" tool has the following arguments:
| Argument | Description | Required/optional |
|---|---|---|
--board-id |
Defined in the <id> field of the BSP manifest |
Required |
--app-id |
Defined in the <id> 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 |
The following example clones the "mtb-example-psoc6-i2s" application with the desired name "Psoc6I2s" configured for the CY8CKIT-062-WIFI-BT BSP into the specified working directory, C:/mtb_projects:
project-creator-cli --board-id CY8CKIT-062-WIFI-BT --app-id mtb-example-psoc6-i2s --user-app-name Psoc6I2s --target-dir "C:/mtb_projects"
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™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mtb_user_guide.pdf).
To work with a different supported kit later, use the Library Manager to choose the BSP for the supported kit. You can invoke the Library Manager GUI tool from the terminal using make library-manager command or use the Library Manager CLI tool "library-manager-cli" to change the BSP.
The "library-manager-cli" tool has the following arguments:
| Argument | Description | Required/optional |
|---|---|---|
--add-bsp-name |
Name of the BSP that should be added to the application | Required |
--set-active-bsp |
Name of the BSP that should be as active BSP for the application | Required |
--add-bsp-version |
Specify the version of the BSP that should be added to the application if you do not wish to use the latest from manifest | Optional |
--add-bsp-location |
Specify the location of the BSP (local/shared) if you prefer to add the BSP in a shared path | Optional |
Following example adds the CY8CPROTO-062-4343W BSP to the already created application and makes it the active BSP for the app:
~/ModusToolbox/tools_3.0/library-manager/library-manager-cli --project "C:/mtb_projects/mtb-example-psoc6-i2s" --add-bsp-name CY8CKIT-062-WIFI-BT --add-bsp-version "latest-v4.X" --add-bsp-location "local"
~/ModusToolbox/tools_3.0/library-manager/library-manager-cli --project "C:/mtb_projects/mtb-example-psoc6-i2s" --set-active-bsp APP_CY8CKIT-062-WIFI-BT
In third-party IDEs
Use one of the following options:
-
Use the standalone Project Creator tool:
-
Launch Project Creator from the Windows Start menu or from {ModusToolbox™ software install directory}/tools_{version}/project-creator/project-creator.exe.
-
In the initial Choose Board Support Package screen, select the BSP, and click Next.
-
In the Select Application screen, select the appropriate IDE from the Target IDE drop-down menu.
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Click Create and follow the instructions printed in the bottom pane to import or open the exported project in the respective IDE.
-
-
Use command-line interface (CLI):
-
Follow the instructions from the In command-line interface (CLI) section to create the application.
-
Export the application to a supported IDE using the
make <ide>command. -
Follow the instructions displayed in the terminal to create or import the application as an IDE project.
-
For a list of supported IDEs and more details, see the "Exporting to IDEs" section of the ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mtb_user_guide.pdf).
If using a PSoC™ 64 "Secure" MCU kit (like CY8CKIT-064B0S2-4343W), the PSoC™ 64 device must be provisioned with keys and policies before being programmed. Follow the instructions in the "Secure Boot" SDK user guide to provision the device. If the kit is already provisioned, copy-paste the keys and policy folder to the application folder.
By default, the code example is configured to work with audio-codec-ak4954a (the macro USE_AK4954A is defined in the Makefile).
CY8CPROTO-062-4343W and CY8CPROTO-063-BLE kits do not support audio-codec-ak4954a, but you can use a third-party module Pmod I2S2. Therefore, while building the code example for CY8CPROTO-062-4343W and CY8CPROTO-063-BLE, remove the macro USE_AK4954A definition from the Makefile.
-
Connect the TFT display shield to the main board. If using the Pmod I2S2 module, connect to the prototyping kit.
-
Connect the board to your PC using the provided USB cable through the USB connector.
-
Connect a speaker or headphone to the audio jack located in the TFT display shield board (CY8CKIT-028-TFT), or to the Pmod I2S2 green audio jack.
-
Program the board using one of the following:
Using Eclipse IDE for ModusToolbox™ software
-
Select the application project in the Project Explorer.
-
In the Quick Panel, scroll down, and click <Application Name> Program (KitProg3_MiniProg4).
Using CLI
From the terminal, execute the
make programcommand 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 -
-
After programming, the application starts automatically. Press the user button to play the short audio "PSoC™ Rocks".
You can debug the example to step through the code. In the IDE, use the <Application Name> Debug (KitProg3_MiniProg4) configuration in the Quick Panel. For details, see the "Program and debug" section in the Eclipse IDE for ModusToolbox™ software user guide.
Note: (Only while debugging) On the CM4 CPU, some code in main() may execute before the debugger halts at the beginning of main(). This means that some code executes twice – once before the debugger stops execution, and again after the debugger resets the program counter to the beginning of main(). See KBA231071 to learn about this and for the workaround.
The CY8CKIT-028-TFT contains the audio codec AK4954A and an audio jack. This allows you to listen to any audio data stream transmitted to the audio codec over the I2S interface. You can connect a speaker or headphones to the audio jack.
PSoC™ 6 MCU streams the data over I2S. This is done by storing a short audio clip in the flash memory and writing it to the Tx FIFO of the I2S hardware block. The wave.h/c files contain the audio data represented as a binary array. You can generate such a file by converting a WAV audio file to a C array. You can use the bin2c tool.
The I2S interface requires a continuous stream of data, which can be satisfied by writing to the Tx FIFO with DMA transfers, or with some code in the interrupt service routine (ISR). In this example, the CY HAL I2S asynchronous function takes care of transferring the data using an ISR.
PSoC™ 6 MCU also provides the clock source for the audio codec. Based on the AK4954A datasheet, this codec requires a 4.096-MHz MCLK and a 1.024-MHz BCLK to sample at 16 kHz. The code example contains an I2C master, through which PSoC™ 6 MCU configures the audio codec. The code example includes the AK4954A library (deps/audio-codec-ak4954a.mtb) dependency to easily configure the AK4954A. If you do not desire to use the AK4954A, you can edit the Makefile to remove the line DEFINES+=USE_AK4954A.
MCLK is generated by using a PWM running at the desired frequency. The clock used to source the PWM and the audio subsystem must be the same to avoid any synchronization issues. This example uses the PLL to source the CPU/peripherals and the audio subsystem. Note that the actual frequencies differ in the firmware because the PLL cannot generate the exact desired frequency.
Note: The desired frequency values set in this code example are not achievable by sourcing the PLL from the IMO (8 MHz). Therefore, slightly different values are enforced in the firmware to avoid issues during the initialization of the PWM and I2S.
Table 1. Application resources
| Resource | Alias/object | Purpose |
|---|---|---|
| I2S (HAL) | i2s | Interfaces the audio codec |
| I2C (HAL) | mi2c | Configures the audio codec |
| GPIO (HAL) | CYBSP_USER_BTN | Starts playback |
| GPIO (HAL) | CYBSP_USER_LED | Indicates playback |
| PWM (HAL) | mclk_pwm | Generates the MCLK for the audio codec |
| Clock (HAL) | audio_clock | Feeds the audio subsystem |
| Clock (HAL) | pll_clock | PLL clock object |
| Clock (HAL) | fll_clock | FLL clock object |
| Clock (HAL) | system_clock | Feeds the system clock |
| Resources | Links |
|---|---|
| Application notes | AN228571 – Getting started with PSoC™ 6 MCU on ModusToolbox™ software AN215656 – PSoC™ 6 MCU: Dual-CPU system design |
| Code examples | Using ModusToolbox™ software 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 audio-codec-ak4954a - Provides functions to support the use of AK4954A audio codec |
| Middleware on GitHub | psoc6-middleware – Links to all PSoC™ 6 MCU middleware |
| Tools | Eclipse IDE for ModusToolbox™ software – ModusToolbox™ software is a collection of easy-to-use software and tools enabling rapid development with Infineon MCUs, covering applications from embedded sense and control to wireless and cloud-connected systems using AIROC™ Wi-Fi and Bluetooth® connectivity devices |
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 PSoC™ 6 MCU devices, see How to design with PSoC™ 6 MCU - KBA223067 in the Infineon Developer community.
Document title: CE218636 - PSoC™ 6 MCU: Inter-IC sound (I2S) audio
| Version | Description of change |
|---|---|
| 1.0.0 | New code example |
| 1.1.0 | Updated to support ModusToolbox™ software v2.1 Updated to use HAL drivers for the I2S block |
| 2.0.0 | Major update to support ModusToolbox™ software v2.2, added support for new kits This version is not backward compatible with ModusToolbox™ software v2.1 Added support to new kits |
| 3.0.0 | Major update to support ModusToolbox™ v3.0 and BSPs v4.X. This version is not backward compatible with previous versions of ModusToolbox™ |
| 3.1.0 | Added support for CY8CEVAL-062S2-LAI-43439M2, and CY8CEVAL-062S2-MUR-4373EM2 kits |
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