STM32F7 MQTT implementation

[AGaru]

Hi everybody,

actually i'm working on a project involving a STM32F7 MCU and a modem Telit 4G/LTE connected via UART. I have to implement MQTT protocol, for which i choosed PAHO (highly used and suggested). Do you suggest working on bare metal or RTOS CMSIS?

In case i'd use CMSIS OS, can you explain me a few general steps/guide line in order to use PAHO (written in embedded C) in my MCU firmware and make it communicate with the Telit 4G modem via UART? So far i've always been using Ethernet and i didn't need to care about the communication between the Ethernet module and the firmware, it was automatically implicit in lwIP (which is also in STM32CubeIDE but usable only by activating the Ethernet port, which i cannot use).

[bayrem.g]

Hi

First you need to check your modem TCP/IP stack if it includes an MQTT application layer ready (to use with AT commands or whatever interface)

If that's the case then you can send commands through UART and use MQTT with no problem.

Else if there is no support for MQTT in your modem then you can use the TCP implementation in the modem where you need to manually create MQTT packets in your program and send them through TCP.

ex: create a CONNECT packet send it and wait for a CONNACK packet for acknowledgement.

-- Bayrem

[AGaru]

Thank you so much. I will check it out monday at work.

[AGaru]

Hello,

I am looking at the LE910C1 datasheet , it seems like it doesn't include an MQTT application layer. Can i use PAHO to create MQTT packets and send them to the telit device via UART?