# FreeRTOS STM32U5 IoT Reference
## Introduction
This project demonstrates how to integrate modular [ FreeRTOS kernel ](https://www.freertos.org/RTOS.html) and [ libraries ](https://www.freertos.org/libraries/categories.html) with hardware enforced security to build more secure updatable cloud connected applications. The project is pre-configured to run on the [ STM32U585 IoT Discovery Kit ](https://www.st.com/en/evaluation-tools/b-u585i-iot02a.html) which includes an kit which includes an [ STM32U5 ](https://www.st.com/en/microcontrollers-microprocessors/stm32u5-series.html) microcontroller.

The *Projects* directory consists of a [Non-TrustZone](Projects/b_u585i_iot02a_ntz) and a [Trusted-Firmware-M-Enabled](Projects/b_u585i_iot02a_tfm) project which both demonstrate connecting to AWS IoT Core and utilizing many of the services available via the MQTT protocol.

Refer to the [ Getting Started Guide ](Getting_Started_Guide.md) for step by step instructions on setting up your development environment.

This includes demonstration tasks for the following AWS services:
* [AWS IoT Device Shadow](https://docs.aws.amazon.com/iot/latest/developerguide/iot-device-shadows.html)
* [AWS IoT Device Defender](https://docs.aws.amazon.com/iot/latest/developerguide/device-defender.html)
* [AWS IoT Jobs](https://docs.aws.amazon.com/iot/latest/developerguide/iot-jobs.html)
* [MQTT File Delivery](https://docs.aws.amazon.com/iot/latest/developerguide/mqtt-based-file-delivery.html)
* [AWS IoT OTA Update](https://docs.aws.amazon.com/freertos/latest/userguide/freertos-ota-dev.html)

The demo projects both connect to AWS IoT core via the included Wi-Fi module and use the [CoreMQTT-Agent](https://github.com/FreeRTOS/coreMQTT-Agent) library to share a single MQTT connection among multiple tasks. These tasks publish environemnt and motion sensor data from a subset of the sensor available on the development board, and demonstrate use of the AWS IoT Device Shadow and Device Defender services.
For more details on the feature, see the [ ST Featured IoT Reference Integration ](https://www.freertos.org/STM32U5/) page on FreeRTOS.org.

## AWS IoT Core Demo Tasks
* MQTT Agent
* IoT Defender
* OTA Update
* Environment Sensor Publishing
* Motion Sensor Publishing

## Key Software Components
### LWIP TCP/IP Stack
See [ lwIP ](https://github.com/lwip-tcpip/lwip) for details. 

### Mbedtls 3.1.0 TLS and Cryptography library
See [ MbedTLS ](https://github.com/Mbed-TLS/mbedtls/tree/d65aeb37349ad1a50e0f6c9b694d4b5290d60e49) for details. 

### Command Line Interface (CLI)
The CLI interface located in the Common/cli directory is used to provision the device. It also provides other Unix-like utilities. See [Common/cli](Common/cli/ReadMe.md) for details. 

### Key-Value Store
The key-value store located in the Common/kvstore directory is used to store runtime configuration values in non-volatile flash memory.
See [Common/kvstore](Common/kvstore/ReadMe.md) for details.

### PkiObject API
The PkiObject API takes care of some of the mundane tasks in converting between different representations of cryptographic objects such as public keys, private keys, and certificates. See [Common/crypto](Common/crypto/ReadMe.md) for details.

### Mbedtls Transport
The *Common/net/mbedtls_transport.c* file contains a transport layer implementation for coreMQTT and coreHTTP which uses mbedtls to encrypt the connection in a way supported by AWS IoT Core.

Optionally, client key / certificate authentication may be used with the mbedtls transport or this parameter may be set to NULL if not needed.
### Cloning the Repository
To clone using HTTPS:
```
git clone https://github.com/FreeRTOS/iot-reference-stm32u5.git --recurse-submodules
```
Using SSH:
```
git clone git@github.com:FreeRTOS/iot-reference-stm32u5 --recurse-submodules
```
If you have downloaded the repo without using the `--recurse-submodules` argument, you should run:
```
git submodule update --init --recursive
```
## Running the demos
To get started running demos, see the [Getting Started Guide](Getting_Started_Guide.md).

## Contribution
See [CONTRIBUTING](https://github.com/FreeRTOS/iot-reference-stm32u5/blob/main/CONTRIBUTING.md) for more information.

## License
Source code located in the *Projects*, *Common*, *Middleware/AWS*, and *Middleware/FreeRTOS* directories are available under the terms of the MIT License. See the LICENSE file for more details.

Other libraries located in the *Drivers* and *Middleware* directories are available under the terms specified in each source file.