Hi,
I can help with your requirement to connect your STM32 to AWS IoT.
You can use the Mongoose Networking Library. It's a lightweight library designed for embedded systems and is a perfect fit for this task. It has built-in support for secure MQTT with TLS, which is exactly what you need to connect to an AWS endpoint, and it's well-documented here.
The most direct guide to solve your problem is this video tutorial we made. It shows step-by-step how to connect an STM32 board to AWS IoT using Mongoose. Moreover, this tutorial references an example of how to use Mongoose as a MQTT client to connect to AWS IOT, which you can also run on a Linux as a quick demo.
Since you are using LwIP as your base stack, you will need to integrate Mongoose on top of it. We provide examples of LwIP projects using Mongoose, along with detailed guide on how to integrate LwIP with Mongoose. You can start directly from this guide to create a simple Mongoose LwIP project initially.
Heads up: I am part of the Mongoose development team. Hope this helps you.
