AWS IoT Device SDK for Embedded C

The AWS IoT Device SDK for Embedded C (C-SDK) is a collection of C source files licensed under MIT that allows embedded applications to securely connect to AWS IoT Core.

Key characteristics:

• Portability: The libraries depend only on standard C libraries, making them portable to various operating systems including RTOS, Linux, Mac, and Windows.
• Modular Design: Many libraries (like MQTT client and JSON parser) are decoupled, allowing you to choose or implement your own.
• Integration: It can be built into custom firmware alongside your application code and OS.
• Sample Usage: Demos are available for POSIX systems (using OpenSSL) and FreeRTOS (using mbedTLS).

Depending on your stability and feature requirements, choose one of the following branches:

• main: Continuous development. Use this for the latest features, but be aware it may contain bugs. For production, use tagged releases.
• v4_beta_deprecated: A deprecated beta version. It receives critical bug fixes and security patches but no new features will be added. Use this only if specifically required by your existing integration.

The AWS IoT Device SDK for Embedded C uses a date-based versioning scheme for the overall SDK releases in the format YYYYMM.NN:

• YYYY: Year
• MM: Month
• NN: Release order within that month (e.g., 00 is the first release).

Example: 202106.01 is the second release in June 2021.

Note: While the SDK itself uses date-based versioning, individual libraries within the SDK maintain their own semantic versioning (X.Y.Z). You should use the semantic version of a specific library to determine the impact of updates on your application.

The legacy OTA library and its associated demo have been removed as of the 202412.00 release. It is recommended to transition to the new modular and composable OTA approach.

• Documentation: Modular OTA approach guide
• Reference Implementation: OTA reference demo

Use the presigned_url_gen.py script to generate pre-signed URLs for S3 HTTP GET and PUT requests. This is useful for providing temporary access to specific S3 objects in the HTTP demo.

Run the script by providing the S3 bucket name and the object key. The output will be formatted as C macros that can be directly used in your project configuration.

./presigned_urls_gen.py --bucket <YOUR BUCKET NAME> --key <YOUR OBJECT KEY>

To begin, you must register your device in AWS IoT Core.

1. Create a Thing: Use the AWS CLI to create a new Thing.

   aws iot create-thing --thing-name device_thing_name

2. Register a Certificate: You can use an existing certificate or create a new one via the AWS Management Console. If using your own CA, follow the AWS documentation for registering CA certificates and creating device certificates.
3. Attach Certificate to Thing: Link the certificate to your Thing using its ARN.

   aws iot attach-thing-principal --thing-name device_thing_name --principal <certificate-arn>

A provisioning template defines how AWS IoT should create resources (like Things and Certificates) when a new device connects using a claim certificate.

1. Navigate to AWS IoT Core > Connect many devices > Create provisioning template.
2. Choose Provisioning devices with claim certificates and click Next.
3. Set the status to active.
4. Enter a template name.
5. Select the IAM role created for AWS IoT.
6. Select the provisioning policy created earlier.
7. Select Don't use a pre-provisioning action.
8. Enable the automatic thing creation option and click Next.
9. Select or create a policy for the device's permissions (e.g., permissions for connecting to IoT, subscribing, or publishing to topics).
10. Click Next, review the settings, and click Create the template.

The presigned_url_gen.py script requires Python 3, boto3, and argparse. Install the necessary Python packages using pip:

pip install boto3 argparse