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Azure RTOS NetX Duo

Azure RTOS NetX Duo is a real time implementation of the TCP/IP standards that works exclusively with Azure RTOS ThreadX as its Real-Time Operating System.

Additionally, Azure IoT Middleware for Azure RTOS is available as an addon to provide platform specific binding code between the Azure RTOS and the Azure SDK for Embedded C which is made available through NetX Duo. This addon enables applications to connect to and use services of Azure IoT Hub.

💡 In its default configuration, Azure RTOS NetX Duo comes with Azure RTOS FileX enabled to support server protocol handlers. However, this has been turned off as Azure RTOS FileX is not provided by the Open IoT SDK.

Fetching

In your application's CMakeLists.txt, include netxduo and its dependency, threadx, in the IOTSDK_FETCH_LIST variable, alongside any other components you need to fetch:

set(IOTSDK_FETCH_LIST
    ...
    netxduo
    threadx
)

💡 This must be done before your application's CMakeLists.txt adds the Open IoT SDK.

Configuration

Available configuration macros are documented in nx_user_sample.h from the Azure RTOS NetX Duo repository. This nx_user_sample.h is also used as the default configuration file, unless you override any macros.

If you would like to override any default configuration macros:

  1. In your application's directory, create a netxduo-config/nx_user.h file.
  2. In the nx_user.h file you have just created, define any macros to override.

  3. In you application's CMakeLists.txt, set NX_USER_FILE to the full path to your nx_user.h file:

    set(NX_USER_FILE "${CMAKE_CURRENT_LIST_DIR}/netxduo-config/nx_user.h")

    💡 CMAKE_CURRENT_LIST_DIR is a CMake built-in variable containing the full path to the directory containing the current CMakeLists.txt.

    💡 This must be done before your application's CMakeLists.txt adds the Open IoT SDK.

The default configuration only enables the TCP/IP stack. If you would also like to enable Azure IoT Middleware for Azure RTOS, in addition to the steps above, you also need to do the following:

  1. In you application's CMakeLists.txt, set NXD_ENABLE_AZURE_IOT to ON:

    set(NXD_ENABLE_AZURE_IOT ON CACHE BOOL "")

    💡 Notice that the way we set NXD_ENABLE_AZURE_IOT is different from NX_USER_FILE earlier. This is because Azure RTOS NetX Duo's CMake support internally declares NXD_ENABLE_AZURE_IOT as a CACHE variable, and it also specifies a very old version of CMake which requires this way of overriding CACHE variables.

    💡 This must be done before your application's CMakeLists.txt adds the Open IoT SDK.

  2. Add the following definitions to the nx_user.h file you have created earlier:

    // Enable Azure IoT Middleware for Azure RTOS
#define NX_ENABLE_EXTENDED_NOTIFY_SUPPORT
#define NX_SECURE_ENABLE
#define NXD_MQTT_CLOUD_ENABLE

// Enable Azure Defender for IoT security module
#define NX_ENABLE_IP_PACKET_FILTER

Linking

In your application's CMakeLists.txt, link the application executable against the library named netxduo alongside any other libraries you need:

target_link_libraries(my_application
    ...
    netxduo
)

💡 Replace my_application with the actual name of your application.

This not only enables the linking of the netxduo static library, but also makes its API headers' include paths available to your application.

Examples

To see the full context of the information in the sections above, you are advised to take a look at

Documentation

For more details of how to use the APIs in your application code, see the official documentations for