Implementing MQTT Communication with Azure IoT Hub on STM32F407

[Noushadalik]

Hello STM Community,

I am currently working on a project using the STM32F407 microcontroller, and I need to implement MQTT communication with Azure IoT Hub for cloud connectivity. The STM32F407 is already connected to the internet through LTE modem via PPPoS, and now I need to integrate MQTT to send data to Azure IoT Hub

• How to set up an MQTT client on STM32 for Azure IoT Hub?
• How to handle TLS/SSL for secure communication with Azure?
• Any resources or example code for device authentication and reconnection logic?

Any guidance or resources for setting this up would be greatly appreciated!

Thanks!

[Noushadalik]

Hello,
Any update Today? 
Can I proceed with the implementation from
 https://github.com/eziya/STM32F4_HAL_ETH_MQTT_CLIENT   ?

[Noushadalik]

Hello,
Any update  Today?

[Guillaume K]

Hello

Did you look at Microsoft documentation to connect to their Azure IoT Hub ?

Microsoft provides C SDKs to connect to azure iot hub:

Azure IoT device and service SDKs - Azure IoT | Microsoft Learn (you need the "device" SDK)

There are 2 SDKs: "Azure IoT C SDK" and "Azure SDK for C". For embedded devices you need "Azure SDK for C" (https://github.com/Azure/azure-sdk-for-c).

General information to connect to Azure IoT Hub:

Use MQTT to communicate with Azure IoT Hub - Azure IoT Hub | Microsoft Learn

if you want low level MQTT connection details:

https://learn.microsoft.com/en-us/azure/iot/iot-mqtt-connect-to-iot-hub#using-the-mqtt-protocol-directly-as-a-device 

If your project uses FreeRTOS, see the link in "Azure IoT SDKs" page to GitHub - Azure/azure-iot-middleware-freertos: Azure IoT Middleware for FreeRTOS

If your project is based on Azure RTOS with Netxduo TCP-IP stack you can have a look at X-CUBE-AZURE or X-CUBE-AZURE-H5 (but they are for STM32U5/STM32H5, not for your STM32F4).

[Noushadalik]

Hi@ Guillaume K

I have reviewed the Azure documentation and would like to integrate the Azure SDK Middleware for FreeRTOS with my STM32F407-based application. However, the Azure documentation mentions that the middleware has only been tested with the following MCUs:

• B-L475E-IOT01A
• B-L4S5I-IOT01A
• STM32H745I-DISCO

For my application, which is based on the STM32F407, which of these MCUs would you recommend I use as a reference for porting?

Additionally, I noticed that the X-CUBE-AZURE package is specifically designed for STM32U5 and STM32H5 devices. Is it possible to adapt X-CUBE-AZURE for the STM32F407, or would this require extensive modifications?

Best regards, 
Noushadali K.

[Noushadalik]

Hi,
Any update Today?

[Guillaume K]

Both X-CUBE-AZURE packages are made with Azure RTOS and Netxduo so it would be difficult to port to FreeRTOS.

I don't have much experience with Azure SDK middleware for FreeRTOS. 

The 3 boards you mention don't have the same network interface as yours (cellular).

I suggest you refer to Microsoft documentation about Azure SDK middleware for FreeRTOS, and your cellular modem documentation.